MedWorm: Intensity-Modulated Radiation Therapy

Intensity Modulated Radiotherapy (IMRT) in the Treatment of Pelvic Lymph Nodes in Locally Advanced Prostate Cancer (LAPCa): a Single UK Institution Experience

Clinical Oncology — Thu, 09 Feb 2012 08:13:42 +0100

Introduction: Evidence is in favour of localised radiotherapy in the treatment of LAPCa. Whether there is added disease control by including the pelvic lymph nodes in the irradiation volume is less clear. This paper describes our experience in using IMRT to treat the pelvic nodes in this patient population. (Source: Clinical Oncology)

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Quantitative comparison of volumetric modulated arc therapy and intensity modulated radiotherapy plan quality in sino-nasal cancer

Journal of Medical Physics — Wed, 08 Feb 2012 05:00:00 +0100

Marimuthu Sankaralingam, Martin Glegg, Suzanne Smith, Allan James, Mohammed RizwanullahJournal of Medical Physics 2012 37(1):8-13The aim of this study was to compare various dosimetric parameters of dynamic mlc intensity modulated radiotherapy (IMRT) plans with volumetric modulated arc therapy (VMAT) plans for sino-nasal cancers, which are rare and complex tumors to treat with radiotherapy. IMRT using five fields, coplanar in the sagittal plane and VMAT employing two coplanar arc plans were created for five patients. The plans were assessed by comparing Conformity Index and Sigma Index (dose homogeneity) in the Planning Target Volume (PTV) and through comparison of dose-volume characteristics to the following organs at risk (OARs): Spinal cord, brainstem, eye, ipsilateral and contralateral...

Evaluation of relative transmitted dose for a step and shoot head and neck intensity modulated radiation therapy using a scanning liquid ionization chamber electronic portal imaging device

Journal of Medical Physics — Wed, 08 Feb 2012 05:00:00 +0100

Mohammad Mohammadi, Eva BezakJournal of Medical Physics 2012 37(1):14-26The dose delivery verification for a head and neck static intensity modulated radiation therapy (IMRT) case using a scanning liquid ionization chamber electronic portal imaging device (SLIC-EPID) was investigated. Acquired electronic portal images were firstly converted into transmitted dose maps using an in-house developed method. The dose distributions were then compared with those calculated in a virtual EPID using the Pinnacle3 treatment planning system (TPS). Using gamma evaluation with the DDmax and DTA criteria of 3%/2.54 mm, an excellent agreement was observed between transmitted dose measured using SLIC-EPID and that calculated by TPS (gamma score approximately 95%) for large MLC fields. In contr...

A National Survey of the Availability of Intensity-Modulated Radiation Therapy and Stereotactic Radiosurgery in Canada

Radiation Oncology — Tue, 07 Feb 2012 05:00:00 +0100

Conclusions: The survey showed a growing adoption of IMRT and SRS in Canada, although the latter was available in less than half of responding centers. Barriers to implementation differed for IMRT compared to SRS. Enhancing human resources is an important consideration in the implementation of new RT technologies, due to the multidisciplinary nature of the planning and treatment process. (Source: Radiation Oncology)

Accelerated Partial Breast Irradiation Using Once-Daily Fractionation: Analysis of 312 Cases with Four Years Median Follow-Up

Radiation Oncology — Mon, 06 Feb 2012 05:00:00 +0100

Conclusions: External beam APBI with once daily fractionation has a low rate of IBF consistent with other published APBI studies. The ASTRO risk stratification did not differentiate a subset of patients with a higher rate of IBF. APBI may be an appropriate treatment for women with DCIS and ILC. (Source: Radiation Oncology)

Proton Beam No Better than IMRT for Prostate Cancer (CME/CE)

MedPage Today Hematology/Oncology — Thu, 02 Feb 2012 18:48:22 +0100

SAN FRANCISCO (MedPage Today) -- For localized prostate cancer, proton beam radiation offers no advantage in minimizing recurrences or side effects, study results suggested. (Source: MedPage Today Hematology/Oncology)

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IMRT superior to CRT, possibly to proton beam for prostate cancer

HemOncToday.com — Thu, 02 Feb 2012 17:03:00 +0100

(Source: HemOncToday.com)

IMRT Superior to Conventional Radiotherapy in Prostate CancerIMRT Superior to Conventional Radiotherapy in Prostate Cancer

Medscape Today Headlines — Wed, 01 Feb 2012 18:18:36 +0100

Intensity-modulated radiation therapy (IMRT) was associated with fewer adverse effects and reduced disease recurrence than conformal radiation therapy. Benefits of proton-beam therapy remain unclear. Medscape Medical News (Source: Medscape Today Headlines)

IMRT Provides Better QoL in Head and Neck CancerIMRT Provides Better QoL in Head and Neck Cancer

Medscape Today Headlines — Tue, 31 Jan 2012 18:13:35 +0100

This is the first long-term study of its kind. Medscape Medical News (Source: Medscape Today Headlines)

Life Quality in Head and Neck Cancer Gets Lift from IMRT

MedPage Today Hematology/Oncology — Tue, 31 Jan 2012 17:00:00 +0100

PHOENIX (MedPage Today) -- Intensity modulated radiation therapy was better than other treatments in boosting long-term quality of life in head-and-neck cancer patients, investigators reported here. (Source: MedPage Today Hematology/Oncology)

IMRT Slows Radiation-Related OsteoradionecrosisIMRT Slows Radiation-Related Osteoradionecrosis

Medscape Today Headlines — Mon, 30 Jan 2012 18:58:28 +0100

Osteoradionecrosis appears delayed with intensity-modulated radiation therapy (IMRT); however, some complications still occur. Medscape Medical News (Source: Medscape Today Headlines)

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Issue Highlights

International Journal of Radiation Oncology * Biology * Physics — Mon, 30 Jan 2012 09:33:53 +0100

In this study the Radiation Therapy Oncology Group-endorsed brachial plexus contouring atlas was used to guide three radiation oncologists to independently delineate this particular structure on treatment planning CT scans from representative head-and-neck cancer patients undergoing IMRT. Inter-observer differences were remarkably small and thus this atlas appears to provide a consistent set of guidelines for contouring with essentially no learning curve. (Source: International Journal of Radiation Oncology * Biology * Physics)

Are the Results of RTOG 0617 Mysterious?

International Journal of Radiation Oncology * Biology * Physics — Mon, 30 Jan 2012 09:33:53 +0100

On June 17, 2011, two of the four arms in the Radiation Therapy Oncology Group (RTOG) 0617 protocol were closed to accrual when a planned interim analysis showed that the higher radiation dose being tested, 74 Gy, could not produce an overall survival benefit compared with the lower, standard dose of 60 Gy . This four-arm study was designed to test radiation with carboplatin and paclitaxel, with or without cetuximab, for Stage III non–small-cell lung cancer (NSCLC). Survival was compared between the two 74-Gy groups and the two 60-Gy groups, and overall survival was found to be better in the lower dose groups (1-year overall survival rate, 70.4% in the 74-Gy groups vs. 81% in the 60-Gy groups—both respectable rates for this stage of disease). However, even though 17 patients died in th...

IMRT offers better outcome for head/neck cancer patients

AuntMinnie.com Headlines — Fri, 27 Jan 2012 21:38:48 +0100

Patients treated with intensity-modulated radiation therapy (IMRT) for head (more) (Source: AuntMinnie.com Headlines)

IMRT Improves Head And Neck Cancer Patients' Long-Term Quality Of Life

Health News from Medical News Today — Fri, 27 Jan 2012 12:00:00 +0100

Patients treated with IMRT for head and neck cancer report an increasingly better quality of life post-treatment when compared to patients receiving other forms of radiation therapy, according to a study presented at the Multidisciplinary Head and Neck Cancer Symposium, sponsored by AHNS, ASCO, ASTRO and SNM. Intensity modulated radiation therapy, or IMRT, is a highly specialized form of external beam radiation therapy that allows the radiation beam to better target and conform to a tumor. It is a newer treatment that has become widely adopted for treating head and neck cancer... (Source: Health News from Medical News Today)

Study: IMRT boosts quality of life for head and neck cancer patients

Health Imaging News — Fri, 27 Jan 2012 10:30:17 +0100

Patients with head and neck cancers who have been treated with intensity-modulated radiation therapy (IMRT) enjoy a better quality of life than those treated with 3D conformal radiation therapy, according to a study presented Jan. 27 at the Multidisciplinary Head and Neck Cancer Symposium in Phoenix. (Source: Health Imaging News)

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Newer radiation technology improves head and neck cancer patients' long-term quality of life

EurekAlert! - Social and Behavioral Science — Thu, 26 Jan 2012 05:00:00 +0100

(American Society for Radiation Oncology) Patients treated with IMRT for head and neck cancer report an increasingly better quality of life post-treatment when compared to patients receiving other forms of radiation therapy, according to a study presented at the Multidisciplinary Head and Neck Cancer Symposium, sponsored by AHNS, ASCO, ASTRO and SNM. (Source: EurekAlert! - Social and Behavioral Science)

Gantry angle dependence in IMRT pre-treatment patient-specific quality controls.

Physica Medica — Wed, 25 Jan 2012 05:00:00 +0100

Authors: Monti AF, Berlusconi C, Gelosa S Abstract Intensity Modulated Radiation Therapy (IMRT) is a complex treatment modality that requires pre-treatment patient-specific quality control (QC) in order to assess a correct treatment delivery. The aim of this work is to investigate pre-treatment patient-specific per-field QCs performed with an on-board EPID at the gantry angle of 0° and at the treatment ones, and to asses if measurements executed at 0° are able to guarantee a correct treatment. Ten patients with prostate cancer were evaluated. Two "verification" plans were created for each patient in order to calculate the dose at the EPID surface: one with all fields positioned at 0° and one with all fields at the actual treatment angles. EPID's mechanical shifts due to gravity ...

The role of intensity modulated radiotherapy in advanced oral cavity carcinoma

Journal of Cancer Research and Therapeutics — Tue, 24 Jan 2012 05:00:00 +0100

SA Bhide, M Ahmed, K Newbold, KJ Harrington, CM NuttingJournal of Cancer Research and Therapeutics 2012 8(6):67-71It is increasingly being recognized that oral cavity cancer incidences are rising globally. Furthermore, these tumors represent a high risk group of tumors comparative to other head and neck tumor sub-sites and have a high preponderance of occult nodal metastases. Surgery alone leads to excellent outcomes in early stage disease. Advanced tumors require adjuvant radiotherapy with or without concomitant chemotherapy. Irradiation using 3D conformal radiotherapy results in high incidence of late radiation side-effects. Xersostomia and mandibular osteoradionecrosis result in most significant effects on patients' quality of life. Intensity modulated radiotherapy (IMRT) is an a...

An end-to-end examination of geometric accuracy of IGRT using a new digital accelerator equipped with onboard imaging system.

Physics in Medicine and Biology — Mon, 23 Jan 2012 08:30:50 +0100

Authors: Wang L, Kielar KN, Mok E, Hsu A, Dieterich S, Xing L Abstract The Varian's new digital linear accelerator (LINAC), TrueBeam™ STx, is equipped with a high dose rate flattening filter free (FFF) mode (6 MV and 10 MV), a high definition multileaf collimator (2.5 mm leaf width), as well as onboard imaging capabilities. A series of end-to-end phantom tests were performed, TrueBeam-based image guided radiation therapy (IGRT), to determine the geometric accuracy of the image-guided setup and dose delivery process for all beam modalities delivered using intensity modulated radiation therapy (IMRT) and RapidArc™. In these tests, an anthropomorphic phantom with a Ball Cube II insert and the analysis software (FilmQA™ (3cognition)) were used to evaluate the accuracy of TrueBeam...

The impact of direct aperture optimization on plan quality and efficiency in complex head and neck IMRT

Radiation Oncology — Mon, 23 Jan 2012 05:00:00 +0100

Conclusions: All IMRT approaches implemented in the different treatment planning systems (TPS) generated clinically acceptable and comparable plans. No superior system in terms of PTV coverage and OAR sparing was found. Major differences in efficiency of the method in terms of calculated MU and treatment times were found. (Source: Radiation Oncology)

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Improved outcomes in buccal squamous cell carcinoma

Head and Neck — Fri, 20 Jan 2012 05:00:00 +0100

ConclusionThe survival of patients with buccal cancer was improved after 2002, which represented the start of intensity‐modulated radiotherapy (IMRT) in our institute. Ipsilateral neck alone irradiation was recommended for T1‐2N0‐1 and small T3N0 disease, and bilateral neck irradiation could be reserved for advanced disease. © 2012 Wiley Periodicals, Inc. Head Neck, 2012 (Source: Head and Neck)

Volumetric change of human papillomavirus–related neck lymph nodes before, during, and shortly after intensity‐modulated radiation therapy

Head and Neck — Fri, 20 Jan 2012 05:00:00 +0100

ConclusionHPV‐related LN behavior during IMRT is extremely variable but somewhat predictable on the basis of nodal density at planning. © 2012 Wiley Periodicals, Inc. Head Neck, 2012 (Source: Head and Neck)

Sensitivity of a helical diode array device to delivery errors in IMRT treatment and establishment of tolerance level for pretreatment QA.

Journal of Applied Clinical Medical Physics — Tue, 17 Jan 2012 11:30:03 +0100

Authors: Garcia-Vicente F, Fernandez V, Bermudez R, Gomez A, Perez L, Zapatero A, Torres JJ Abstract The aim of this study is to determine the gantry angle and multileaf collimator (MLC) gap error-detection threshold of a diode helical array with an inserted micro-ionization chamber in order to use this device for the pretreatment quality assurance (QA) of intensity-modulated radiation therapy (IMRT) treatments. Implications on the dose-volume histograms (DVHs) of the patient treatments will also be considered for the establishment of a QA protocol with a reasonable tolerance level. Three dynamic IMRT HN (head and neck) and prostate treatments were studied. Random and systematic variations of gantry angle and systematic errors in MLC gap width of the clinical treatments were analyz...

A study of segment weight optimization with the CMS XiO step-and-shoot IMRT technique for prostate cancer.

Journal of Applied Clinical Medical Physics — Tue, 17 Jan 2012 11:30:03 +0100

This study shows that the segment weight optimization method significantly reduces the total number of segments and the dose to the rectum for IMRT prostate cancer. It also resulted in fewer monitor units for most of the prostate cases observed in this study. PMID: 22231214 [PubMed - in process] (Source: Journal of Applied Clinical Medical Physics)

Dose to craniofacial region through portal imaging of pediatric brain tumors.

Journal of Applied Clinical Medical Physics — Tue, 17 Jan 2012 11:30:03 +0100

Authors: Hitchen CJ, Osa EO, Dewyngaert K, Chang J, Narayana A Abstract The purpose of this study was to determine dose to the planning target volume (PTV) and organs at risk (OARs) from portal imaging (PI) of the craniofacial region in pediatric brain tumor patients treated with intensity-modulated radiation therapy (IMRT). Twenty pediatric brain tumor patients were retrospectively studied. Each received portal imaging of treatment fields and orthogonal setup fields in the craniofacial region. The number of PI and monitor units used for PI were documented for each patient. Dose distributions and dose-volume histograms were generated to quantify the maximum, minimum, and mean dose to the PTV, and the mean dose to OARs through PI acquisition. The doses resulting from PI are reported...

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An opposed matched field IMRT technique for prostate cancer patients with bilateral prosthetic hips.

Journal of Applied Clinical Medical Physics — Tue, 17 Jan 2012 11:30:03 +0100

In conclusion, the use of this technique should be considered for patients with bilateral metal hip implants who do not meet dose-volume criteria by conventional IMRT techniques. PMID: 22231205 [PubMed - in process] (Source: Journal of Applied Clinical Medical Physics)

Protecting the oral mucosa in patients with oral tongue squamous cell carcinoma treated postoperatively with intensity‐modulated radiotherapy: A randomized study

The Laryngoscope — Tue, 17 Jan 2012 05:00:00 +0100

Conclusions:OR‐SP PO‐IMRT for patients with oral tongue SCC resulted in a significant decrease in the severity of acute mucositis and improved quality of life. The sparing of the oral mucosa outside of the PTV is safe and does not compromise oncologic outcomes. (Source: The Laryngoscope)

Intensity-modulated radiotherapy for nasopharyngeal carcinoma: improvement of the therapeutic ratio with helical tomotherapy versus segmental multileaf collimator-based techniques.

The British Journal of Radiology — Tue, 17 Jan 2012 05:00:00 +0100

Conclusion: The superior dosimetric outcome observed with HT appeared to translate into moderately improved clinical outcomes with respect to salivary sparing. Prospective trials are needed to validate this gain in the therapeutic ratio. PMID: 22253350 [PubMed - as supplied by publisher] (Source: The British Journal of Radiology)

Does VMAT for treatment of NSCLC patients increase the risk of pneumonitis compared to IMRT ? - A planning study.

Acta Oncologica — Tue, 17 Jan 2012 05:00:00 +0100

Conclusions. Using IMRT as reference for the VMAT optimization it was possible to implement VMAT in the clinic with no increase in estimated risk of RP. Thus, toxicity is not expected to be a hindrance to using VMAT and will profit from the shorter delivery time with VMAT compared to IMRT. PMID: 22248064 [PubMed - as supplied by publisher] (Source: Acta Oncologica)

Response to “The Correlation of Osteoradionecrosis and Dental Events With Dosimetric Parameters in Intensity-Modulated Radiation Therapy (IMRT) for Head-and-Neck Cancer.” (Int J Radiat Oncol Biol Phys 2011;81:e207–e213.)

International Journal of Radiation Oncology * Biology * Physics — Sat, 14 Jan 2012 19:43:01 +0100

To the Editor: We read with great interest the article by Gomez et al. on correlation of osteoradionecrosis (ORN) and dental events with dosimetric parameters in intensity-modulated radiation therapy (IMRT) for head-and-neck cancer.The authors provide additional data that IMRT is associated with a very low incidence of ORN (1%) . Noteworthy, this low incidence may indeed make the establishment of statistically relevant correlations between dose, dental events, and ORN difficult. Additionally, as stated by the authors, follow-up was too short to enable firm conclusions on the benefit of IMRT to be drawn. Additionally, the number of patients lost to follow-up with planned extractions was 12%, indeed 20 of the 29 patients with dental events, which we think may be a serious statistical pitfal...

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Der ICRU-Report 83: Verordnung, Dokumentation und Kommunikation der fluenzmodulierten Photonenstrahlentherapie (IMRT)

Strahlentherapie und Onkologie — Tue, 10 Jan 2012 17:01:08 +0100

Der ICRU-Report 83: Verordnung, Dokumentation und Kommunikation der fluenzmodulierten Photonenstrahlentherapie (IMRT) Content Type Journal ArticleCategory Literatur kommentiertPages 97-100DOI 10.1007/s00066-011-0015-xAuthors N. Hodapp, Klinik für Strahlenheilkunde, Universitätsklinikum Freiburg, Freiburg, Deutschland Journal Strahlentherapie und OnkologieOnline ISSN 1439-099XPrint ISSN 0179-7158 Journal Volume Volume 188 Journal Issue Volume 188, Number 1 (Source: Strahlentherapie und Onkologie)

Failure patterns and survival in patients with nasopharyngeal carcinoma treated with intensity modulated radiation in Northwest China: A pilot study

Radiation Oncology — Tue, 10 Jan 2012 05:00:00 +0100

Conclusions: IMRT with or without chemotherapy can improve the long term survival of NPC patients in Northwest ChinaDistant metastasis becomes the main cause of treatment failure. Age and anemia before radiotherapy were the main prognosis factors of NPC patients. (Source: Radiation Oncology)

Head and neck cancer: Bevacizumab an option for nasopharyngeal carcinoma?

Nature Clinical Practice Oncology — Tue, 10 Jan 2012 05:00:00 +0100

Nature Reviews Clinical Oncology 9, 66 (2012). doi:10.1038/nrclinonc.2011.209 A recent phase II trial has shown that bevacizumab is tolerated by patients with nasopharyngeal carcinoma. The trial assessed patients with grade IIB–IVB disease and combined treatment with bevacizumab and cisplatin with intensity-modulated radiation therapy. There were no grade 5 adverse events, which was one (Source: Nature Clinical Practice Oncology)

Volumetric modulated arc therapy for nasopharyngeal carcinoma: A dosimetric comparison with TomoTherapy and step-and-shoot IMRT.

Mon, 09 Jan 2012 05:00:00 +0100

CONCLUSIONS: Our results indicate that VMAT provides better sparing of normal tissue, homogeneity, and conformity than IMRT, and shorter delivery time than HT. PMID: 22236614 [PubMed - as supplied by publisher] (Source: Radiotherapy and Oncology : journal of the European Society for Therapeutic Radiology and Oncology)

Does weight loss predict accuracy of setup in head and neck cancer patients treated with Intensity-Modulated Radiation Therapy?

La Radiologia Medica — Sat, 07 Jan 2012 16:53:44 +0100

Conclusions Weight loss is not a good clinical parameters for predicting an increase of setup errors. Other clinical and/or anthropometrical features should be prospectively evaluated in order to assess the need for re-planning. Content Type Journal ArticleCategory Radiotherapy / RadioterapiaPages 1-7DOI 10.1007/s11547-011-0765-7Authors B. De Bari, Département de Radiothérapie Oncologie, Centre Hospitalier Lyon Sud, Chemin du Grand-Revoyet, 69310 Pierre-Bénite, FranceM. Ait Erraisse, Département de Radiothérapie Oncologie, Centre Hospitalier Lyon Sud, Chemin du Grand-Revoyet, 69310 Pierre-Bénite, FranceT. Chekrine, Département de Radiothérapie Oncologie, Centre Hospitalier Lyon Sud, Chemin du Grand-Revoyet, 69310 Pierre-Bénite, FranceM. Rabilloud, Service de...

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Dosimetric integration of daily mega-voltage cone-beam CT for image-guided intensity-modulated radiotherapy

Strahlentherapie und Onkologie — Wed, 04 Jan 2012 06:48:29 +0100

Conclusion Both methods of incorporating the additional MV-CBCT dose into the treatment plan are suitable for clinical practice. The dose distribution of the target volume could be achieved as conformal as with the orgIMRT plan, while only a moderate increase of mean dose to OAR was observed. Content Type Journal ArticleCategory Original articlePages 1-7DOI 10.1007/s00066-011-0021-zAuthors A. Zabel-du Bois, Department of Radiooncology, University of Heidelberg, INF 400, 69120 Heidelberg, GermanyS. Nill, Department of Medical Physics, German Cancer Research Center, Heidelberg, GermanyS. Ulrich, Department of Medical Physics, German Cancer Research Center, Heidelberg, GermanyU. Oelfke, Department of Medical Physics, German Cancer Research Center, Heidelberg, GermanyB....

Imaging of hypoxia using PET and MRI.

Current Pharmaceutical Biotechnology — Mon, 02 Jan 2012 05:00:00 +0100

This article provides an overview over the various methods, with a particular emphasis on PET and MRI for imaging of hypoxia, and reviews their performance in preclinical and clinical studies. PMID: 22214501 [PubMed - as supplied by publisher] (Source: Current Pharmaceutical Biotechnology)

[Articles] Independent validation of genes and polymorphisms reported to be associated with radiation toxicity: a prospective analysis study

The Lancet Oncology — Sun, 01 Jan 2012 05:00:00 +0100

SummaryBackgroundSeveral studies have reported associations between radiation toxicity and single nucleotide polymorphisms (SNPs) in candidate genes. Few associations have been tested in independent validation studies. This prospective study aimed to validate reported associations between genotype and radiation toxicity in a large independent dataset.Methods92 (of 98 attempted) SNPs in 46 genes were successfully genotyped in 1613 patients: 976 received adjuvant breast radiotherapy in the Cambridge breast IMRT trial (ISRCTN21474421, n=942) or in a prospective study of breast toxicity at the Christie Hospital, Manchester, UK (n=34). (Source: The Lancet Oncology)

A convolution model for obtaining the response of an ionization chamber in static non standard fields.

Medical Physics — Sun, 01 Jan 2012 05:00:00 +0100

Conclusions: This method could be implemented in TPS in order to calculate dosimetry correction factors when an experimental IMRT treatment verification with in-phantom ionization chamber is performed. The miss-response of the IC due to the nonreference conditions could be quickly corrected by this method rather than employing MC derived correction factors. This method can be considered as an alternative to the plan-class associated correction factors proposed recently as part of an IAEA work group on nonstandard field dosimetry. PMID: 22225319 [PubMed - as supplied by publisher] (Source: Medical Physics)

An efficient inverse radiotherapy planning method for VMAT using quadratic programming optimization.

Medical Physics — Sun, 01 Jan 2012 05:00:00 +0100

Conclusion: Quadratic programming is an alternative approach for inverse planning which generates clinically satisfying plans in comparison to the clinical system and constitutes an efficient optimization process characterized by uniqueness and reproducibility of the solution. PMID: 22225315 [PubMed - in process] (Source: Medical Physics)

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Motion-compensated estimation of delivered dose during external beam radiation therapy: Implementation in Philips' Pinnacle(3) treatment planning system.

Medical Physics — Sun, 01 Jan 2012 05:00:00 +0100

Conclusions: This paper presents results from the implementation of an algorithm on a commercially available treatment planning system that quantifies the dosimetric effects of interfractional and intrafractional motion in external beam radiation therapy (EBRT) of prostate cancer. The implementation of this algorithm within a commercial treatment planning system such as Pinnacle(3) enables easy deployment in the existing clinical workflow. The results of the PDD tests validate the implementation of the DiDIT algorithm in Pinnacle(3), in comparison with previously published results. PMID: 22225314 [PubMed - in process] (Source: Medical Physics)

Dose homogeneity specification for reference dosimetry of nonstandard fields.

Medical Physics — Sun, 01 Jan 2012 05:00:00 +0100

Conclusions: The authors have shown that a plan-class specific correction factor can be specified as a function of plan evaluation parameters especially for Farmer-type chambers. This work provides a recipe based on quantifying dose distribution to accurately select air-filled ionization chamber correction factors for nonstandard fields. PMID: 22225310 [PubMed - in process] (Source: Medical Physics)

In aqua vivo EPID dosimetry.

Medical Physics — Sun, 01 Jan 2012 05:00:00 +0100

Conclusions: With the in aqua vivo approach for the verification of lung cancer treatments (IMRT and VMAT), we can achieve results with the same accuracy as obtained during in vivo EPID dosimetry of sites without large inhomogeneities. PMID: 22225306 [PubMed - as supplied by publisher] (Source: Medical Physics)

Evaluating dosimetric accuracy of flattening filter free compensator-based IMRT: Measurements with diode arrays.

Medical Physics — Sun, 01 Jan 2012 05:00:00 +0100

Conclusions: MAPCHECK analysis demonstrates high passing rates with the stringent γ(2%/2 mm) and local normalization criteria combination. The geometry of the ARCCHECK array creates a stress test for the FFF TPS model because of the shallow depth of the entrance diodes and large air cavity. Hence, the ARCCHECK γ-analysis passing rates are lower than with the MAPCHECK, while still on par with TG-119. PMID: 22225304 [PubMed - in process] (Source: Medical Physics)

Aperture superposition dose model versus pencil beam superposition dose model for a finite size Cobalt-60 source for tomotherapy deliveries.

Medical Physics — Sun, 01 Jan 2012 05:00:00 +0100

Conclusions: The results presented in this paper indicate that the AS model provides better accuracy than the FSPB model when calculating dose for fan beams from large radiation sources. The implementation of this model to the current treatment planning systems has the scope of advancing Co-60 based IMRT and tomotherapy. PMID: 22225289 [PubMed - in process] (Source: Medical Physics)

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TomoTherapy MLC verification using exit detector data.

Medical Physics — Sun, 01 Jan 2012 05:00:00 +0100

Conclusions: The exit detectors in the TomoTherapy treatment systems can provide valuable information about MLC behavior during delivery. A technique to estimate the TomoTherapy binary MLC leaf open time from exit detector signals is described. This technique is shown to be both robust and accurate for delivery verification. PMID: 22225283 [PubMed - in process] (Source: Medical Physics)

Implementation of EPID transit dosimetry based on a through-air dosimetry algorithm.

Medical Physics — Sun, 01 Jan 2012 05:00:00 +0100

Conclusions: A prediction of the transit PDI behind a phantom or patient can be created for the purposes of treatment verification via an extension of the Van Esch through-air PDI algorithm. The results of the verification measurements through phantoms indicate that further investigation through patients during their treatments is warranted. PMID: 22225278 [PubMed - in process] (Source: Medical Physics)

Evaluation of the accuracy of 3DVH software estimates of dose to virtual ion chamber and film in composite IMRT QA.

Medical Physics — Sun, 01 Jan 2012 05:00:00 +0100

Conclusions: 3DVH + mapcheck 2 predicts the same absolute dose, the percent of pixels failing the gamma metric, and the percent of pixels failing 2% or 3% dose difference tolerance tests as one would have obtained had one made measurements in solid water phantom using an ion chamber and coronal film instead of a diode array. This is also a necessary although not sufficient condition for validation of the accuracy of 3DVH predictions of the 3D dose using beam-by-beam measurements. PMID: 22225277 [PubMed - in process] (Source: Medical Physics)

Dosimetric investigation of breath-hold intensity-modulated radiotherapy for pancreatic cancer.

Medical Physics — Sun, 01 Jan 2012 05:00:00 +0100

Conclusions: This study suggested that the baseline drift of >5 mm should be avoided in the BH-IMRT. PMID: 22225274 [PubMed - in process] (Source: Medical Physics)

IMRT, laser surgery improves survival in head/neck cancer

AuntMinnie.com Headlines — Thu, 29 Dec 2011 07:00:00 +0100

The combination of functional resection laser surgery and intensity-modulated (more) (Source: AuntMinnie.com Headlines)

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Preliminary comparison of helical tomotherapy and mixed beams of unmodulated electrons and intensity modulated radiation therapy for treating superficial cancers of the parotid gland and nasal cavity

Radiation Oncology — Wed, 28 Dec 2011 05:00:00 +0100

Conclusions: Mixed beam treatments offer some dosimetric advantages over IMRT or helical tomotherapy for target depths that do not exceed the useful range of the electron beam. Adding a small IMRT component (e.g., IMRT:electron weighting = 1:4) to electron beam plans markedly improved target dose homogeneity and conformity for the cases examined in this study. (Source: Radiation Oncology)

Potential and limitations of advanced MRI and CT.

Cancer Imaging — Mon, 26 Dec 2011 17:24:03 +0100

Authors: Schlemmer HP Abstract Radiotherapy has been considerably improved by three-dimensional intensity-modulated radiation therapy (imRT). The technique of dose painting affords precise adaption of the dose distribution to the complex geometry of the tumor including an improved block out of surrounding healthy structures. Progress in image-guided radiotherapy enables tracking of tumor and healthy organs repeatedly before or even during each treatment session, thereby taking account temporal changes of tumor positions due to organ movement or tumor geometry caused by treatment effects. Adequate registration of the tumor localization, its heterogeneous viability and temporal variations during radiotherapy enable optimization of radiotherapy treatment effects by concurrently preser...

Volumetric response evaluation after intensity modulated radiotherapy in patients with supratentorial gliomas.

Technology in Cancer Research and Treatment — Sat, 24 Dec 2011 16:49:00 +0100

Authors: Cho KH, Choi JH, Kim JY, Lee SH, Yoo H, Shin KH, Kim TH, Moon SH, Lee SH, Park HC Abstract Radiotherapy is frequently indicated to treat cerebral gliomas. Accurate response evaluation after radiotherapy is essential to determine the efficacy of treatment. We retrospectively analyzed the volumetric tumor response after simultaneous integrated boost-intensity modulated radiotherapy (SIB-IMRT) in patients with gliomas. Thirty-five patients (Grade II, 7 patients; Grade III, 12; and Grade IV, 16) were treated with SIB-IMRT with a median total dose of 55.9 Gy/26 fractions for Grade II and 60 Gy/25 fractions for Grade III-IV tumors. Tumor responses were evaluated for enhancing volume on post-gadolinium T1-weighted images (Vgd) and hyper-intensity volume on T2-weighted FLAIR image...

Urethra sparing - potential of combined Nickel-Titanium stent and intensity modulated radiation therapy in prostate cancer.

Fri, 23 Dec 2011 05:00:00 +0100

CONCLUSIONS: A new concept for urethra dose reduction is presented. The method relies on the use of a Ni-Ti stent as a fiducial marker combined with intensity modulated radiotherapy. Theoretical calculations suggest preserved tumour control. PMID: 22197354 [PubMed - as supplied by publisher] (Source: Radiotherapy and Oncology : journal of the European Society for Therapeutic Radiology and Oncology)

Cone beam CT for organs motion evaluation in pediatric abdominal neuroblastoma.

Fri, 23 Dec 2011 05:00:00 +0100

CONCLUSIONS: With the use of daily CBCT we may be able to reduce the PTV margin. If CBCT is not used daily, a wider margin is needed. PMID: 22197353 [PubMed - as supplied by publisher] (Source: Radiotherapy and Oncology : journal of the European Society for Therapeutic Radiology and Oncology)

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Monitoring Dosimetric Impact of Weight Loss With Kilovoltage (KV) Cone Beam CT (CBCT) During Parotid-Sparing IMRT and Concurrent Chemotherapy

International Journal of Radiation Oncology * Biology * Physics — Fri, 23 Dec 2011 05:00:00 +0100

Conclusions: Although patient weight loss and parotid volume shrinkage was observed, overall, there was no significant excess dose to the organs at risk. No replanning was felt necessary for this patient cohort, but a larger patient sample will be investigated to further confirm these results. Nevertheless, kilovoltage CBCT is a valuable tool for patient setup verification and monitoring of dosimetric variation during radiotherapy. (Source: International Journal of Radiation Oncology * Biology * Physics)

Dosimetric Study of Current Treatment Options for Radiotherapy in Retinoblastoma

International Journal of Radiation Oncology * Biology * Physics — Fri, 23 Dec 2011 05:00:00 +0100

Conclusions: Inverse planned image-guided radiotherapy delivered using HT or VMAT gives better conformity index, improved orbital bone and brain sparing, and a lower integral dose than other techniques. (Source: International Journal of Radiation Oncology * Biology * Physics)

Prospective phase II trial of cetuximab plus VMAT-SIB in locally advanced head and neck squamous cell carcinoma

Strahlentherapie und Onkologie — Thu, 22 Dec 2011 12:51:01 +0100

Conclusion The here reported toxicity data are promising and encouraging in regard to the adoption of moderate hypofractionation with VMAT-SIB techniques, when cetuximab is concomitantly administered. Content Type Journal ArticleCategory Original articlePages 1-7DOI 10.1007/s00066-011-0006-yAuthors F. Alongi, Radiotherapy and Radiosurgery, Humanitas Cancer Center, Istituto Clinico Humanitas, Via Manzoni 56, 20098 Rozzano (Milan), ItalyM. Bignardi, Radiotherapy and Radiosurgery, Humanitas Cancer Center, Istituto Clinico Humanitas, Via Manzoni 56, 20098 Rozzano (Milan), ItalyI. Garassino, Oncology, Humanitas Cancer Center, Istituto Clinico Humanitas, Rozzano (Milan), ItalyS. Pentimalli, Radiotherapy and Radiosurgery, Humanitas Cancer Center, Istituto Clinico Humanitas,...

Patterns of Practice in Intensity-modulated Radiation Therapy and Image-guided Radiation Therapy for Prostate Cancer in Japan

Japanese Journal of Clinical Oncology — Thu, 22 Dec 2011 05:00:00 +0100

Conclusions The results of the survey identified current patterns in the treatment planning and delivery processes of external-beam radiation therapy for prostate cancer in Japan. (Source: Japanese Journal of Clinical Oncology)

VMAT and Step-and-Shoot IMRT in Head and Neck Cancer

Strahlentherapie und Onkologie — Wed, 21 Dec 2011 19:54:42 +0100

Conclusions: VMAT results in dose distributions for H&N patients that are at least comparable with treatments performed with step-and-shoot IMRT. Two new tools to quantify the quality of dose distributions are presented and have proven to be useful. Content Type Journal ArticleCategory Original ArticlePages 820-825DOI 10.1007/s00066-011-2267-xAuthors Rolf Wiehle, Klinik für Strahlenheilkunde, Uniklinik Freiburg, Freiburg, GermanyStefan Knippen, Klinik für Strahlenheilkunde, Uniklinik Freiburg, Freiburg, GermanyAnca-Ligia Grosu, Klinik für Strahlenheilkunde, Uniklinik Freiburg, Freiburg, GermanyGregor Bruggmoser, Klinik für Strahlenheilkunde, Uniklinik Freiburg, Freiburg, GermanyNorbert Hodapp, Klinik für Strahlenheilkunde, Uniklinik Freiburg, Freiburg, Germany...

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Dosimetry comparison between volumetric modulated arc therapy with RapidArc and fixed field dynamic IMRT for local-regionally advanced nasopharyngeal carcinoma

Chinese Journal of Cancer Research — Wed, 21 Dec 2011 19:52:18 +0100

Conclusion For locally advanced NPC, both RapidArc and IMRT reached the clinic requirement. The target volume coverage was similar for the different techniques. The RapidArc technique showed some improvements in OARs and other tissue sparing while using reduced MUs and delivery time. Content Type Journal ArticleCategory Original ArticlePages 259-264DOI 10.1007/s11670-011-0259-0Authors Bao-min Zheng, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Radiotherapy, Peking University School of Oncology, Beijing Cancer Hospital & Institute, Beijing, 100142 ChinaXiao-xia Dong, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Radiotherapy, Peking University School of Oncology...

Evaluation of multiple-atlas-based strategies for segmentation of the thyroid gland in head and neck CT images for IMRT.

Physics in Medicine and Biology — Sat, 17 Dec 2011 00:51:39 +0100

Authors: Chen A, Niermann KJ, Deeley MA, Dawant BM Abstract Segmenting the thyroid gland in head and neck CT images is of vital clinical significance in designing intensity-modulated radiation therapy (IMRT) treatment plans. In this work, we evaluate and compare several multiple-atlas-based methods to segment this structure. Using the most robust method, we generate automatic segmentations for the thyroid gland and study their clinical applicability. The various methods we evaluate range from selecting a single atlas based on one of three similarity measures, to combining the segmentation results obtained with several atlases and weighting their contribution using techniques including a simple majority vote rule, a technique called STAPLE that is widely used in the medical imaging ...

Predictive value of MRI in the localization, staging, volume estimation, assessment of aggressiveness, and guidance of radiotherapy and biopsies in prostate cancer

Journal of Magnetic Resonance Imaging — Fri, 16 Dec 2011 20:39:29 +0100

AbstractMultiparametric magnetic resonance imaging (MRI) has the potential of being the ideal prostate cancer (PCa) assessment tool. Information gathered with multiparametric MRI can serve therapy choice, guidance of interventions, and treatments. The purpose of this review is to discuss the potential role of multiparametric MRI in focal therapy with respect to patient selection and directing (robot‐guided) biopsies and intensity‐modulated radiation therapy (IMRT). Multiparametric MRI is a versatile and promising technique. It appears to be the best available imaging technique at the moment in localizing, staging (primary as well as recurrent disease, and local as well as distant disease), determining aggressiveness, and volume of PCa. However, larger study populations in multicenter s...

Dosimetric Comparison of Combined Intensity-Modulated Radiotherapy (IMRT) and Proton Therapy Versus IMRT Alone for Pelvic and Para-Aortic Radiotherapy in Gynecologic Malignancies

International Journal of Radiation Oncology * Biology * Physics — Fri, 16 Dec 2011 05:00:00 +0100

Conclusions: Compared with IMRT alone, PSPT/IMRT and IMPT/IMRT had a statistically significant decrease in dose to the small and large bowel and kidneys, while maintaining excellent planning target volume coverage. Further studies should be done to correlate the clinical significance of these findings. (Source: International Journal of Radiation Oncology * Biology * Physics)

Rational Use of Intensity-Modulated Radiation Therapy: The Importance of Clinical Outcome

Seminars in Radiation Oncology — Fri, 16 Dec 2011 01:20:01 +0100

During the last 2 decades, intensity-modulated radiation therapy (IMRT) became a standard technique despite its drawbacks of volume delineation, planning, robustness of delivery, challenging quality assurance, and cost as compared with non-IMRT. The theoretic advantages of IMRT dose distributions are generally accepted, but the clinical advantages remain debatable because of the lack of clinical assessment of the effort that is required to overshadow the disadvantages. Rational IMRT use requires a positive advantage/drawback balance. Only 5 randomized clinical trials (RCTs), 3 in the breast and 2 in the head and neck, which compare IMRT with non-IMRT (2-dimensional technique in four fifths of the trials), have been published (as of March 2011), and all had toxicity as the primary endpoint....

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Quantitative Metrics for Assessing Plan Quality

Seminars in Radiation Oncology — Fri, 16 Dec 2011 01:20:01 +0100

Despite many studies over the last 3 decades that have attempted to explicitly quantify the decision-making process for radiotherapy treatment plan evaluation, judgments of an individual plan's degree of quality are still largely subjective and can show inter- and intra-practitioner variability even if the clinical treatment goals are the same. Several factors conspire to confound the full quantification of treatment plan quality, including uncertainties in dose response of cancerous and normal tissue, the rapid pace of new technology adoption, and the human component of treatment planning. However, new developments in clinical informatics and automation are lowering the bar for developing and implementing quantitative metrics into the treatment planning process. This review discusses gene...

Intensity-modulated radiotherapy for sinonasal teratocarcinosarcoma

Journal of Huazhong University of Science and Technology -- Medical Sciences -- — Thu, 15 Dec 2011 16:45:13 +0100

We report here two cases of SNTCS that were treated by IMRT. One patient was given extensive IMRT involving elective neck irradiation. Follow-up examinations revealed no recurrence and metastasis 3.5 years after IMRT. Another patient simultaneously suffered from multiple systematical diseases and was administered involved-field radiotherapy. He was found to have a marginal recurrence during the follow up and eventually died 8 months after disease diagnosis. It was suggested in this study that appropriate use of IMRT for the treatment of SNTCS may achieve excellent local control. Content Type Journal ArticlePages 857-860DOI 10.1007/s11596-011-0691-xAuthors Gang Peng, Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 4300...

External validation of three dimensional conformal radiotherapy based NTCP models for patient-rated xerostomia and sticky saliva among patients treated with intensity modulated radiotherapy.

Mon, 12 Dec 2011 05:00:00 +0100

CONCLUSION: 3D-CRT based models for patient-rated xerostomia and sticky saliva among head and neck cancer patients treated with primary radiotherapy or chemoradiation turned out to be less valid for patients treated with IMRT. The main message from these findings is that models developed in a population treated with a specific technique cannot be generalised and extrapolated to a population treated with another technique without external validation. PMID: 22169766 [PubMed - as supplied by publisher] (Source: Radiotherapy and Oncology : journal of the European Society for Therapeutic Radiology and Oncology)

Submandibular gland-sparing intensity modulated radiotherapy in the treatment of head and neck cancer: Sites of locoregional relapse and survival.

Acta Oncologica — Mon, 12 Dec 2011 05:00:00 +0100

Conclusion. In selected head and neck cancer patients who are estimated to have a low risk of cancer recurrence at the nodal levels I-II and who are treated with SMG-sparing IMRT the risk of cancer recurrence at the vicinity of the spared salivary glands is low. PMID: 22150115 [PubMed - as supplied by publisher] (Source: Acta Oncologica)

Fast IMRT by increasing the beam number and reducing the number of segments

Radiation Oncology — Fri, 09 Dec 2011 05:00:00 +0100

Conclusions: 2-Step Fast plans are suited to reduce the delivery time, especially if the data handling time per beam is short. The plan quality can be retained or even increased for fewer segments provided more gantry angles are used. (Source: Radiation Oncology)

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Reirradiation for recurrent or second primary head and neck cancers.

Bulletin du Cancer — Fri, 09 Dec 2011 05:00:00 +0100

Authors: Mouttet-Audouard R, Gras L, Comet B, Lartigau E Abstract Recurrences or second primary head and neck cancers meant, for a long time, therapeutic dead ends. Surgery was the standard treatment, but could only be achieved in 25% of the patients. The GETTEC-GORTEC (99-01) randomized trial showed that radiochemotherapy improved disease-free survival for a highly selected population. For inoperable patients, three options can be discussed: supportive care only, chemotherapy or radiotherapy with or without chemotherapy. The EXTREME protocol showed that combining platinum, 5FU and cetuximab improved overall survival for recurrent or metastatic forms. This is certainly the best option for advanced forms, which are not accessible to radiotherapy. Concerning radiotherapy, only one r...

Does IGRT ensure target dose coverage of head and neck IMRT patients?

Mon, 05 Dec 2011 05:00:00 +0100

CONCLUSION: IGRT repositioning ensured target volume coverage, but significant dose variations were observed for OARs. The dosimetric impact of anatomic changes during radiotherapy was of lesser importance than the effects of IGRT repositioning. PMID: 22146294 [PubMed - as supplied by publisher] (Source: Radiotherapy and Oncology : journal of the European Society for Therapeutic Radiology and Oncology)

Editorial Comment

Urology — Thu, 01 Dec 2011 05:00:00 +0100

Urologists are coming under close scrutiny by third-party payers and the government for their ownership of ancillary services, including laboratory services such as blood work and pathology, imaging equipment, treatment facilities including surgicenters, lithotripters, and intensity-modulated radiation therapy. These relationships have not gone unnoticed in the lay press and are frequently recounted on the front pages of the nation's more prominent newspapers. In this article, Hollingsworth and colleagues at the University of Michigan looked at whether urologist investment in lithotripters in the state of Michigan changed practice patterns, specifically with regard to ureteroscopy (URS) and shock wave lithotripsy (SWL). The authors queried the state's ambulatory surgery database to perform...

Dosimetric evaluation of conventional radiotherapy, 3‐D conformal radiotherapy and direct machine parameter optimisation intensity‐modulated radiotherapy for breast cancer after conservative surgery

Australasian Radiology — Thu, 01 Dec 2011 05:00:00 +0100

Conclusions: In WBI of breast cancer after conservative surgery, 3DCRT and DMPO‐IMRT improved the homogeneity and conformity of the PTV compared with CR. Meanwhile, 3DCRT reduced the irradiated volumes of OARs at all dose levels listed in our study while DMPO‐IMRT reduced the irradiated volumes of OARs in high‐dose areas but increased the irradiated volumes of OARs in low‐dose areas. (Source: Australasian Radiology)

Dose comparisons for conformal, IMRT and VMAT prostate plans

Australasian Radiology — Thu, 01 Dec 2011 05:00:00 +0100

Conclusions: Single‐ and double‐arc VMAT consistently resulted in favourable or slightly superior dosimetry when compared with static gantry IMRT for prostate cases. Both the VMAT techniques and static gantry IMRT resulted in superior critical tissue sparing when compared with conformal plans. (Source: Australasian Radiology)

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[Intensity-modulated radiotherapy and involved-node concept in patients with Hodgkin lymphoma: Experience of the Gustave-Roussy Institute].

Cancer Radiotherapie — Thu, 01 Dec 2011 05:00:00 +0100

CONCLUSION: Our results suggest that patients with localized Hodgkin lymphoma can be safely and efficiently treated using the involved node irradiation concept and intensity modulated irradiation. PMID: 22116023 [PubMed - in process] (Source: Cancer Radiotherapie)

Effect of Photon-Beam Energy on VMAT and IMRT Treatment Plan Quality and Dosimetric Accuracy for Advanced Prostate Cancer

Strahlentherapie und Onkologie — Wed, 30 Nov 2011 04:38:07 +0100

Conclusion: For static and rotational IMRT, 15 MV photons did not show advantages over 6 and 10 MV high energy photon beams in large volume pelvic plans. For the investigated TPS and linac combination, 10 MV photon beams can be used as the general purpose energy for intensity modulation. Content Type Journal ArticleCategory Original ArticlePages 1-7DOI 10.1007/s00066-011-1150-0Authors Marlies Pasler, Lake Constance Radiation Oncology Center Singen–Friedrichshafen, Singen, GermanyDietmar Georg, Department of Radiotherapy, Medical University Vienna, Vienna, AustriaHolger Wirtz, Lake Constance Radiation Oncology Center Singen–Friedrichshafen, Singen, GermanyJohannes Lutterbach, Lake Constance Radiation Oncology Center Singen–Friedrichshafen, Singen, Germany ...

Impact of Gantry Rotation Time on Plan Quality and Dosimetric Verification – Volumetric Modulated Arc Therapy (VMAT) vs. Intensity Modulated Radiotherapy (IMRT)

Strahlentherapie und Onkologie — Wed, 30 Nov 2011 04:38:06 +0100

Conclusion: VMAT90, VMAT120, and IMRT achieved comparable treatment plans. Slower gantry movement in VMAT120 plans only improves dosimetric quality for highly complex targets. Content Type Journal ArticleCategory Original ArticlePages 1-8DOI 10.1007/s00066-011-2263-1Authors Marlies Pasler, Gemeinschaftspraxis für Strahlentherapie Singen–Friedrichshafen, Friedrichshafen, GermanyHolger Wirtz, Gemeinschaftspraxis für Strahlentherapie Singen–Friedrichshafen, Friedrichshafen, GermanyJohannes Lutterbach, Gemeinschaftspraxis für Strahlentherapie Singen–Friedrichshafen, Friedrichshafen, Germany Journal Strahlentherapie und OnkologieOnline ISSN 1439-099XPrint ISSN 0179-7158 (Source: Strahlentherapie und Onkologie)

Dosimetric and radiobiological comparison of helical tomotherapy, forward-planned intensity-modulated radiotherapy and two-phase conformal plans for radical radiotherapy treatment of head and neck squamous cell carcinomas.

The British Journal of Radiology — Sun, 27 Nov 2011 15:13:59 +0100

Conclusion: TCP for the single-phase plans was comparable to that of HT plans, whereas that for the two-phase technique was lower. Centres that cannot provide IMRT for the radical treatment of all patients could implement the single-phase technique as standard to attain comparable TCP. However, IMRT produced better UCP, thereby enabling the exploration of dose escalation. PMID: 22101580 [PubMed - in process] (Source: The British Journal of Radiology)

Radiotherapy: technical aspects

Medicine — Sat, 26 Nov 2011 02:35:24 +0100

Abstract: Radiotherapy is involved in the treatment of at least 40% of cancer patients. Whereas palliative radiotherapy is typically given over 1–10 treatments, radical treatments can extend over 4–8 weeks. Radiation is delivered using external beam machines or by inserting radioactive isotopes. Localization of tumours has been transformed with spiral computed tomography, magnetic resonance imaging and positron emission tomography scanning. Modern imaging, computing and delivery systems have led to dramatic improvements in external-beam radiotherapy such as intensity-modulated radiotherapy (IMRT). Image-guided radiotherapy (IGRT) increases accuracy by imaging moving targets during treatment. Stereotactic radiotherapy allows very high doses to be delivered very precisely in a small numb...

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Clinical impact of margin reduction on late toxicity and short-term biochemical control for patients treated with daily on-line image guided IMRT for prostate cancer.

Fri, 25 Nov 2011 05:00:00 +0100

Authors: Crehange G, Mirjolet C, Gauthier M, Martin E, Truc G, Peignaux-Casasnovas K, Azelie C, Bonnetain F, Naudy S, Maingon P Abstract To evaluate the impact of PTV reduction when delivering image-guided IMRT (IG-IMRT) for patients with prostate cancer. Between 2001 and 2007, 165 men were treated with daily IG-IMRT using a 3D ultrasound-based system. Median dose prescribed to the prostate was 78Gy [74Gy-78Gy]. Patients were stratified regarding the CTV to the PTV margin: group A (n=87)=5mm or group B (n=78)=10mm. Late toxicity was scored using the CTC v3.0 scale. Biochemical progression-free survival (bPFS) was calculated using the Phoenix definition. Grade 2 genitourinary toxicity was 7.0% for group A and 6.6% for group B (p=1.00). Grade 2 gastrointestinal toxicity was 1.2% and ...

The effect of gantry spacing resolution on plan quality in a single modulated arc optimization.

Journal of Applied Clinical Medical Physics — Wed, 23 Nov 2011 18:48:02 +0100

This study investigates the relation between the number of segments and plan quality in VMAT optimization for a single modulated arc. Five prostate, five lung, and five head-and-neck (HN) patient plans were studied retrospectively. For each case, four VMAT plans were generated. The plans differed only in the number of control points used in the optimization process. The control points were spaced 2°, 3°, 4°, and 6° apart, respectively. All of the optimization parameters were the same among the four schemes. The 2° spacing plan was used as a reference to which the other three plans were compared. The plan quality was assessed by comparison of dose indices (DIs) and generalized equivalent uniform doses (gEUDs) for targets and critical structures. All optimization schemes generated clini...

Measurements to predict the time of target replacement of a helical tomotherapy.

Journal of Applied Clinical Medical Physics — Wed, 23 Nov 2011 18:48:02 +0100

Authors: Kampfer S, Schell S, Duma MN, Wilkens JJ, Kneschaurek P Abstract Intensity-modulated radiation therapy (IMRT) requires more beam-on time than normal open field treatment. Consequently, the machines wear out and need more spare parts. A helical tomotherapy treatment unit needs a periodical tungsten target replacement, which is a time consuming event. To be able to predict the next replacement would be quite valuable. We observed unexpected variations towards the end of the target lifetime in the performed pretreatment measurements for patient plan verification. Thus, we retrospectively analyze the measurements of our quality assurance program. The time dependence of the quotient of two simultaneous dose measurements at different depths within a phantom for a fixed open fiel...

Expanding the use of real-time electromagnetic tracking in radiation oncology.

Journal of Applied Clinical Medical Physics — Wed, 23 Nov 2011 18:48:02 +0100

Authors: Shah AP, Kupelian PA, Willoughby TR, Meeks SL Abstract In the past 10 years, techniques to improve radiotherapy delivery, such as intensity-modulated radiation therapy (IMRT), image-guided radiation therapy (IGRT) for both inter- and intrafraction tumor localization, and hypofractionated delivery techniques such as stereotactic body radiation therapy (SBRT), have evolved tremendously. This review article focuses on only one part of that evolution, electromagnetic tracking in radiation therapy. Electromagnetic tracking is still a growing technology in radiation oncology and, as such, the clinical applications are limited, the expense is high, and the reimbursement is insufficient to cover these costs. At the same time, current experience with electromagnetic tracking applie...

Comparative analysis of SmartArc-based dual arc volumetric-modulated arc radiotherapy (VMAT) versus intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma.

Journal of Applied Clinical Medical Physics — Wed, 23 Nov 2011 18:48:02 +0100

Authors: Lee TF, Chao PJ, Ting HM, Lo SH, Wang YW, Tuan CC, Fang FM, Su TJ Abstract The purpose of this study was to evaluate and quantify the planning performance of SmartArc-based volumetric-modulated arc radiotherapy (VMAT) versus fixed-beam intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC) using a sequential mode treatment plan. The plan quality and performance of dual arc-VMAT (DA-VMAT) using the Pinnacle3 Smart-Arc system (clinical version 9.0; Philips,Fitchburg, WI, USA) were evaluated and compared with those of seven-field (7F)-IMRT in 18 consecutive NPC patients. Analysis parameters included the conformity index (CI) and homogeneity index (HI) for the planning target volume (PTV), maximum and mean dose, normal tissue complication probability (NTCP)...

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The dosimetric effect of mixed-energy IMRT plans for prostate cancer.

Journal of Applied Clinical Medical Physics — Wed, 23 Nov 2011 18:48:02 +0100

Authors: Park JM, Choi CH, Ye SJ, Ha SW Abstract We investigated the effect of mixing high- and low-energy photon beams on the quality of intensity-modulated radiation therapy (IMRT) plans for patients with prostate cancer. Three different plans for each of twenty patients were generated using either 6 MV or 15 MV alone, and both 6 and 15 MV beams. All the planning parameters, goals, and constraints were set to be identical except beam energy. The dose distributions were similar in terms of target coverage, conformity, and homogeneity regardless of beam energy. The V70Gy of rectal wall in 6 MV, 15 MV and mixed-energy plans was 16.7%, 17.9%, and 16.3%, respectively, while V40Gy was 55.6%, 53.2%, and 50%. The mean dose to femoral heads in 6 MV, 15 MV, and mixed-energy plans were 31.7...

Comparison of bulk electron density and voxel-based electron density treatment planning.

Journal of Applied Clinical Medical Physics — Wed, 23 Nov 2011 18:48:02 +0100

Authors: Karotki A, Mah K, Meijer G, Meltsner M Abstract The use of magnetic resonance imaging (MRI) alone for radiation planning is limited by the lack of electron density for dose calculations. The purpose of this work is to evaluate the dosimetric accuracy of using bulk electron density as a substitute for computed tomography (CT)-derived electron density in intensity-modulated radiation therapy (IMRT) treatment planning of head and neck (HN) cancers. Ten clinically-approved, CT-based IMRT treatment plans of HN cancer were used for this study. Three dose distributions were calculated and compared for each treatment plan. The first calculation used CT-derived density and was assumed to be the most accurate. The second calculation used a homogeneous patient density of 1 g/cm3. For...

Irradiation with protons for the individualized treatment of patients with locally advanced rectal cancer: A planning study with clinical implications

Radiotherapy and Oncology — Wed, 23 Nov 2011 05:00:00 +0100

Conclusions: Planning results suggest that treatment with protons can improve the therapeutic tolerance for the irradiation of rectal cancer, particularly for patients scheduled for an irradiation with an intensified chemotherapy regimen and identified to be at high risk for acute therapy-related toxicity. However, clinical experiences and long-term observation are needed to assess tumor response and related toxicity rates. (Source: Radiotherapy and Oncology)

Concomitant intensity modulated boost during whole breast hypofractionated radiotherapy – A feasibility and toxicity study

Radiotherapy and Oncology — Wed, 23 Nov 2011 05:00:00 +0100

Abstract: Background: Breast cancer sensitivity to large fraction size may be enhanced using hypofractionated concomitant boost radiotherapy (CBRT), thereby shortening overall treatment time. This ethics approved, prospective single cohort feasibility study was designed to evaluate the dosimetry and toxicity of CBRT using an intensity-modulated radiotherapy (IMRT) technique, compared with a standard sequential boost technique (SBT).Methods: Fifteen women (11 right-sided; 4 left-sided) received 42.4Gy to the whole breast and an additional 10.08Gy to the tumor bed in 16 daily fractions, using IMRT and standard dose constraints. Each patient was replanned with the SBT, using mixed photon–electrons. Clinical target volume (CTV), dose evaluation volume (DEV), and organs at risk (OAR) dose dis...

In Response to Dr. Yang and Colleagues

International Journal of Radiation Oncology * Biology * Physics — Tue, 22 Nov 2011 20:40:02 +0100

This study proves that the tumor volume reduction rate (VRR) is a predictor for local control in oropharyngeal cancer (OPC) and hypopharyngeal cancer (HPC) patients after intensity-modulated radiation therapy. However, there are some limitations in this retrospective study. (Source: International Journal of Radiation Oncology * Biology * Physics)

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Concomitant intensity modulated boost during whole breast hypofractionated radiotherapy - A feasibility and toxicity study.

Mon, 21 Nov 2011 05:00:00 +0100

CONCLUSIONS: CBRT using IMRT improved boost coverage and lowered OAR doses, compared with SBT. Toxicities were acceptable using a daily boost of 3.28Gy. While resource utilization was greater, overall treatment time was reduced. PMID: 22112781 [PubMed - as supplied by publisher] (Source: Radiotherapy and Oncology : journal of the European Society for Therapeutic Radiology and Oncology)

Irradiation with protons for the individualized treatment of patients with locally advanced rectal cancer: A planning study with clinical implications.

Mon, 21 Nov 2011 05:00:00 +0100

CONCLUSIONS: Planning results suggest that treatment with protons can improve the therapeutic tolerance for the irradiation of rectal cancer, particularly for patients scheduled for an irradiation with an intensified chemotherapy regimen and identified to be at high risk for acute therapy-related toxicity. However, clinical experiences and long-term observation are needed to assess tumor response and related toxicity rates. PMID: 22112780 [PubMed - as supplied by publisher] (Source: Radiotherapy and Oncology : journal of the European Society for Therapeutic Radiology and Oncology)

The potential benefit of swallowing sparing intensity modulated radiotherapy to reduce swallowing dysfunction: An in silico planning comparative study.

Mon, 21 Nov 2011 05:00:00 +0100

CONCLUSIONS: New predictive models for swallowing dysfunction were applied to show potential reductions in physician and patient-rated swallowing dysfunction with IMRT that was specifically optimised to spare SWOARs. PMID: 22112778 [PubMed - as supplied by publisher] (Source: Radiotherapy and Oncology : journal of the European Society for Therapeutic Radiology and Oncology)

Comparison of anisotropic aperture based intensity modulated radiotherapy with 3D-conformal radiotherapy for the treatment of large lung tumors

Radiotherapy and Oncology — Mon, 21 Nov 2011 05:00:00 +0100

Abstract: Purpose/objective(s): IMRT allows dose escalation for large lung tumors, but respiratory motion may compromise delivery. A treatment plan that modulates fluence predominantly in the transversal direction and leaves the fluence identical in the direction of the breathing motion may reduce this problem.Materials/methods: Planning-CT-datasets of 20 patients with Stage I–IV non small cell lung cancer (NSCLC) formed the basis of this study. A total of two IMRT plans and one 3D plan were created for each patient. Prescription dose was 60Gy to the CTV and 70Gy to the GTV. For the 3D plans an energy of 18MV photons was used. IMRT plans were calculated for 6MV photons with 13 coplanar and with 17 noncoplanar beams. Robustness of the used method of anisotropic modulation toward breathing...

Summaries: International Kidney Cancer Symposium

Kidney Cancer Association — Sun, 20 Nov 2011 21:48:07 +0100

Conclusion: there is no increased risk of doing the lymph node dissection early on. Dr. Eggener-CON Basics Lymph node dissections rarely done, even for large tumors, because there is no proven therapeutic or staging benefit for low risk patients. A Mayo study revealed no data showing therapeutic benefit in high risk patients. For clinically node negative high risk patients, there is staging value but no proven therapeutic benefit. Rate of positive nodes is associated with stage and grade; the higher the stage and grade, the more likely there will be positive nodes. A tumor > 10 cm with sarcomatoid features and tumor necrosis is also associated with positive nodes. Looking at several studies, t...

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Advances of Precise Radiotherapy for Lung Cancer

Chinese Journal of Lung Cancer — Sun, 20 Nov 2011 05:00:00 +0100

At present lung tumor radiation therapy has entered the accurate radiotherapy era. Precise radiotherapy includes intensity modulated radiotherapy (IMRT), image-guided radiotherapy (IGRT) and stereotactic body radiotherapy (SBRT). During the process of implementing precise radiotherapy, these problems should be fully considered to ensure executing precise radiotherapy accurately: patient positioning, controlling of the lung tumor motion, selecting of image techniques, PTV margin, dose prescription and reporting, arrangement of beams, controlling of dose volume and treatment delivering. DOI: 10.3779/j.issn.1009-3419.2011.11.12 (Source: Chinese Journal of Lung Cancer)

Improved Normal Tissue Sparing in Head and Neck Radiotherapy Using Biological Cost Function Based-IMRT.

Technology in Cancer Research and Treatment — Sat, 19 Nov 2011 16:18:53 +0100

This study observed improved OAR avoidance with BBO planning. Further investigations will be undertaken to review any clinical benefit of this improved planned dosimetry. PMID: 22066597 [PubMed - in process] (Source: Technology in Cancer Research and Treatment)

A benchmark study on 883 nasopharyngeal cancer patients treated in two Italian Centres from 1977 to 2000. Part II: evolving technical choices and toxicity patterns

La Radiologia Medica — Fri, 18 Nov 2011 06:53:24 +0100

Conclusions Results of this benchmark study may have implications for understanding and developing new radiotherapy techniques, such as three-dimensional conformal radiotherapy (3D-CRT) and, in particular, intensity-modulated radiotherapy (IMRT) for NPC patients. Content Type Journal ArticleCategory Radiotherapy / RadioterapiaPages 1-10DOI 10.1007/s11547-011-0756-8Authors S. M. Magrini, Istituto del Radio “O. Alberti”, Spedali Civili, Piazzale Spedali Civili 1, 25123 Brescia, ItalyS. Tonoli, Istituto del Radio “O. Alberti”, Spedali Civili, Piazzale Spedali Civili 1, 25123 Brescia, ItalyL. Costa, Istituto del Radio “O. Alberti”, Spedali Civili, Piazzale Spedali Civili 1, 25123 Brescia, ItalyN. Pasinetti, Istituto del Radio “O. Alberti”, Spedali Civili,...

A benchmark study on 883 nasopharyngeal cancer patients treated in two Italian Centres from 1977 to 2000. Part I: evolving technical choices and survival

La Radiologia Medica — Fri, 18 Nov 2011 06:53:24 +0100

Conclusions Results of this benchmark study may be useful for understanding the development of new radio-therapy techniques for NPC, such as three-dimensional conformal radiotherapy (3D-CRT) and particularly intensity-modulated radiotherapy (IMRT). Content Type Journal ArticleCategory Radiotherapy / RadioterapiaPages 1-25DOI 10.1007/s11547-011-0755-9Authors S. Tonoli, Istituto del Radio “O. Alberti”, Spedali Civili, Piazzale Spedali Civili 1, 25123 Brescia, ItalyS. M. Magrini, Istituto del Radio “O. Alberti”, Spedali Civili, Piazzale Spedali Civili 1, 25123 Brescia, ItalyL. Costa, Istituto del Radio “O. Alberti”, Spedali Civili, Piazzale Spedali Civili 1, 25123 Brescia, ItalyF. Paiar, Radioterapia, Ospedale Careggi, Firenze, ItalyG. Simontacchi, Radiotera...

Megavoltage cone beam computed tomography: Commissioning and evaluation of patient dose

Journal of Medical Physics — Fri, 18 Nov 2011 05:00:00 +0100

Hassan S Abou-elenein, Ehab M Attalla, H Ammar, Ismail Eldesoky, Mohamed Farouk, Mohamed S ZaghloulJournal of Medical Physics 2011 36(4):205-212The improvement in conformal radiotherapy techniques enables us to achieve steep dose gradients around the target which allows the delivery of higher doses to a tumor volume while maintaining the sparing of surrounding normal tissue. One of the reasons for this improvement was the implementation of intensity-modulated radio therapy (IMRT) by using linear accelerators fitted with multi-leaf collimator (MLC), Tomo therapy and Rapid arc. In this situation, verification of patient set-up and evaluation of internal organ motion just prior to radiation delivery become important. To this end, several volumetric image-guided techniques have been developed ...

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Radiotherap-e. An e-learning programme in advanced radiotherapy techniques

Radiography — Fri, 18 Nov 2011 05:00:00 +0100

Over the past decade, radiotherapy has seen unprecedented advances in technology and techniques, many of which incorporate new concepts and skills which may be unfamiliar to the current workforce. In 2007, the Department of Health National Radiotherapy Action Group (NRAG) and the NHS Cancer Reform Strategy laid out a vision for a world class radiotherapy service in the UK, with equitable access to advanced radiotherapy techniques across the nation by 2012 . A survey by the Radiotherapy Development Board in 2009 found however that progress with implementing advanced radiotherapy techniques in the UK, specifically intensity modulated radiotherapy (IMRT), has been slower than expected . Lack of appropriately trained physicists (86%), oncologists (54%), dosimetrists (54%) and radiographers (20...

Dosimetric evaluation of breast radiotherapy in a dynamic phantom.

Physics in Medicine and Biology — Thu, 17 Nov 2011 21:55:41 +0100

Authors: Menon G, Pudney D, Smith W Abstract This phantom study quantifies changes in delivered dose due to respiratory motion for four breast radiotherapy planning techniques: three intensity-modulated techniques (forward-planned, surface-compensated and hybrid intensity-modulated radiation therapy (IMRT)); using a combination of open fields and inverse planned IMRT) and a 2D conventional technique. The plans were created on CT images of a wax breast phantom with a cork lung insert, and dose distributions were measured using films inserted through slits in the axial and sagittal planes. Films were irradiated according to each plan under a static (modeling breathhold) and three dynamic conditions-isocenter set at mid-respiratory cycle with motion amplitudes of 1 and 2 cm and at end...

The clinical impact of the couch top and rails on IMRT and arc therapy.

Physics in Medicine and Biology — Thu, 17 Nov 2011 21:55:22 +0100

Authors: Pulliam KB, Howell RM, Followill D, Luo D, White RA, Kry SF Abstract The clinical impact of the Varian Exact Couch on dose, volume coverage to targets and critical structures, and tumor control probability (TCP) has not been described. Thus, we examined their effects on IMRT and arc therapy. Five clinical prostate patients were planned with both 6 MV eight-field IMRT and 6 MV two-arc RapidArc techniques using the Eclipse treatment planning system. These plans neglected treatment couch attenuation, as is a common clinical practice. Dose distributions were then recalculated in Eclipse with the inclusion of the Varian Exact Couch (imaging couch top) and the rails in varying configurations. The changes in dose and coverage were evaluated using the dose-volume histograms from e...

Dosimetric variations of target volumes and organs at risk in nasopharyngeal carcinoma intensity-modulated radiotherapy.

The British Journal of Radiology — Thu, 17 Nov 2011 05:00:00 +0100

Conclusions: There are no significant dose changes for target volumes and spinal cord, and doses to brainstem and both parotids changed individually during NPC IMRT. Replanning helps to spare bilateral parotids. PMID: 22096217 [PubMed - as supplied by publisher] (Source: The British Journal of Radiology)

Comparison of anisotropic aperture based intensity modulated radiotherapy with 3D-conformal radiotherapy for the treatment of large lung tumors.

Thu, 17 Nov 2011 05:00:00 +0100

CONCLUSIONS: Anisotropic modulation of IMRT improves dose delivery over 3D-RT and renders IMRT plans robust toward breathing induced organ motion, effectively preventing interplay effects. PMID: 22100654 [PubMed - as supplied by publisher] (Source: Radiotherapy and Oncology : journal of the European Society for Therapeutic Radiology and Oncology)

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Effects of 3-Dimensional Conformal or Intensity-modulated Radiotherapy on Dental Pulp Sensitivity during and after the Treatment of Oral or Oropharyngeal Malignancies

Journal of Endodontics — Wed, 16 Nov 2011 05:00:00 +0100

Conclusions: RT decreased the number of teeth responding to PST after doses greater than 30 to 35 Gy. The type of RT (3D-RT or IMRT) had no influence on the pulp responses to PST after the conclusion of RT. (Source: Journal of Endodontics)

Successful treatment of anaplastic meningioma metastatic to cervical lymph nodes

Head and Neck — Tue, 15 Nov 2011 05:00:00 +0100

ConclusionCervical lymph node metastasis of anaplastic meningioma is potentially treatable with surgical resection and IMRT, although further studies with long‐term follow‐up are necessary. © 2011 Wiley Periodicals, Inc. Head Neck, 2011 (Source: Head and Neck)

Adjuvant radiotherapy after extrapleural pneumonectomy for mesothelioma. Prospective analysis of a multi-institutional series

Radiotherapy and Oncology — Mon, 14 Nov 2011 05:00:00 +0100

Conclusion: Postoperative RT with modern techniques is an effective method to obtain excellent local control and cure rates in mesothelioma patients submitted to EPP. (Source: Radiotherapy and Oncology)

Adjuvant radiotherapy after extrapleural pneumonectomy for mesothelioma. Prospective analysis of a multi-institutional series.

Fri, 11 Nov 2011 05:00:00 +0100

CONCLUSION: Postoperative RT with modern techniques is an effective method to obtain excellent local control and cure rates in mesothelioma patients submitted to EPP. PMID: 22079529 [PubMed - as supplied by publisher] (Source: Radiotherapy and Oncology : journal of the European Society for Therapeutic Radiology and Oncology)

Dosimetric comparison of three different external beam whole breast irradiation techniques.

Advances in Therapy — Tue, 08 Nov 2011 05:00:00 +0100

CONCLUSIONS: 2D-RT could not be performed safely on the intact breast in any of the subgroups. FiF-IMRT is a superior technique for breast dosimetry, and normal tissue. For patients with large breast size or separation, further intensive techniques must be investigated. PMID: 22076811 [PubMed - as supplied by publisher] (Source: Advances in Therapy)

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Boosting runtime-performance of photon pencil beam algorithms for radiotherapy treatment planning.

Physica Medica — Mon, 07 Nov 2011 05:00:00 +0100

Authors: Siggel M, Ziegenhein P, Nill S, Oelfke U Abstract Pencil beam algorithms are still considered as standard photon dose calculation methods in Radiotherapy treatment planning for many clinical applications. Despite their established role in radiotherapy planning their performance and clinical applicability has to be continuously adapted to evolving complex treatment techniques such as adaptive radiation therapy (ART). We herewith report on a new highly efficient version of a well-established pencil beam convolution algorithm which relies purely on measured input data. A method was developed that improves raytracing efficiency by exploiting the capability of modern CPU architecture for a runtime reduction. Since most of the current desktop computers provide more than one calc...

Concurrent Temozolomide and Dose-Escalated Intensity Modulated Radiation Therapy in Newly Diagnosed Glioblastoma.

Clinical Cancer Research — Mon, 07 Nov 2011 05:00:00 +0100

CONCLUSIONS: GBM patients can safely receive standard TMZ with 75 Gy in 30 fractions, delivered using IMRT. The median OS of 20.1 months is promising. Furthermore, MET-PET appears to predict regions of high risk of recurrence not defined by MRI, suggesting that further improvements may be possible by targeting metabolically active regions. PMID: 22065084 [PubMed - as supplied by publisher] (Source: Clinical Cancer Research)

GPU-based fast Monte Carlo simulation for radiotherapy dose calculation.

Physics in Medicine and Biology — Sat, 05 Nov 2011 19:59:07 +0100

Authors: Jia X, Gu X, Graves YJ, Folkerts M, Jiang SB Abstract Monte Carlo (MC) simulation is commonly considered to be the most accurate dose calculation method in radiotherapy. However, its efficiency still requires improvement for many routine clinical applications. In this paper, we present our recent progress toward the development of a graphics processing unit (GPU)-based MC dose calculation package, gDPM v2.0. It utilizes the parallel computation ability of a GPU to achieve high efficiency, while maintaining the same particle transport physics as in the original dose planning method (DPM) code and hence the same level of simulation accuracy. In GPU computing, divergence of execution paths between threads can considerably reduce the efficiency. Since photons and electrons und...

Raster-scanned carbon ion therapy for malignant salivary gland tumors: acute toxicity and initial treatment response

Radiation Oncology — Wed, 02 Nov 2011 04:00:00 +0100

Conclusion: Acute toxicity remains low in IMRT with carbon ion boost also in R1-resected patients and patients undergoing re-irradiation. R2-resected patients showed high rates of treatment response, though follow-up is too short to assess long-term disease control. (Source: Radiation Oncology)

Volumetric modulated arc therapy: a review of current literature and clinical use in practice.

The British Journal of Radiology — Tue, 01 Nov 2011 04:00:00 +0100

This article aims to discuss the current use of VMAT techniques in practice and review the available data from planning and clinical outcome studies in various tumour sites including prostate, pelvis (lower gastrointestinal, gynaecological), head and neck, thoracic, central nervous system, breast and other tumour sites. PMID: 22011829 [PubMed - in process] (Source: The British Journal of Radiology)

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[B-mode ultrasound for defining planning target volume in intensity-modulated radiotherapy for prostate cancer].

Journal of Southern Medical University — Tue, 01 Nov 2011 04:00:00 +0100

CONCLUSION: The ultrasound imagining guided localization, with simple operation, nonirradiation and small systemic error, can be real-time corrected. PMID: 22126782 [PubMed - in process] (Source: Journal of Southern Medical University)

Feasibility of TCP-based Dose Painting by Numbers Applied to a Prostate Case with (18)F-Choline PET Imaging.

Zeitschrift fur Medizinische Physik — Mon, 31 Oct 2011 04:00:00 +0100

CONCLUSION: If the distribution of radiobiological parameters within a tumor is known, this model can be used to create a dose-painting by numbers plan which maximizes the TCP. It could be shown, that such a heterogeneous dose distribution is technically feasible. PMID: 22047806 [PubMed - as supplied by publisher] (Source: Zeitschrift fur Medizinische Physik)

Dysphagia

Strahlentherapie und Onkologie — Fri, 28 Oct 2011 16:57:32 +0100

Conclusion The findings of this study suggest that more emphasis should be placed on structured clinical diagnostics, therapy, and rehabilitation of deglutition problems. This means in particular to not only spare the parotids while planning the irradiation, but also to take into consideration the important structures for deglutition, like the retropharyngeal muscles. Content Type Journal ArticleCategory Original ArticlePages 1-6DOI 10.1007/s00066-011-2275-xAuthors Julia Maurer, Department of Radiotherapy, Regensburg University Medical Center, Regensburg, GermanyMatthias Hipp, Department of Radiotherapy, Regensburg University Medical Center, Regensburg, GermanyChristof Schäfer, Department of Radiotherapy, Hospital St. Elisabeth Straubing, Straubing, GermanyOliver K...

Comparison of different adjuvant radiotherapy approaches in childhood bladder/prostate rhabdomyosarcoma treated with conservative surgery

Strahlentherapie und Onkologie — Fri, 28 Oct 2011 16:57:31 +0100

Conclusion All modalities provide good sparing of normal tissue. BT and IMPT are superior to IMRT with regard to doses on rectum and growth plates. BT is equivalent to IMPT in adequately selected tumors. Content Type Journal ArticleCategory Original ArticlePages 1-7DOI 10.1007/s00066-011-2261-3Authors Frank Heinzelmann, Department of Radiation Oncology, University of Tuebingen, Tuebingen, GermanyDaniela Thorwarth, Department of Radiation Oncology/Medical Physics, University of Tuebingen, Tuebingen, GermanyUlf Lamprecht, Department of Radiation Oncology/Medical Physics, University of Tuebingen, Tuebingen, GermanyTheodor W. Kaulich, Department of Radiation Oncology/Medical Physics, University of Tuebingen, Tuebingen, GermanyJörg Fuchs, Department of Pediatric Surgery,...

Dose verification of IMRT by use of a COMPASS transmission detector

Radiological Physics and Technology — Fri, 28 Oct 2011 16:45:04 +0100

Abstract Our purpose in this study was to evaluate the fundamental accuracy of reconstructed dose distributions from the COMPASS system using specific MLC test patterns and complicated IMRT neck plans. The COMPASS-reconstructed dose distributions were compared with those measured with EPID, MapCHECK, and EDR2 film and as well as Monte Carlo-calculated dose profiles with use of square-wave chart patterns of 20-, 10-, and 5-mm gaps and step and pyramid patterns. Additionally, the COMPASS dose distributions for clinical IMRT neck plans were tested. The COMPASS dose profiles were almost in agreement with the Monte Carlo-calculated dose profiles and point doses measured with MapCHECK for 20- and 10-mm gap patterns. The dose profile for a 5-mm gap pattern showed a narrow width d...

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Dosimetric and motion analysis of margin-intensive therapy by stereotactic ablative radiotherapy for resectable pancreatic cancer

Radiation Oncology — Fri, 28 Oct 2011 04:00:00 +0100

Conclusions: AC does not significantly reduce the limited motion of structures in close proximity to the MIT target and does not significantly increase the dose to OARs that can be displaced by the compression plate. The treatment planning techniques evaluated in this study have different advantages with no clearly superior method in our analysis. Dose to adjacent vessels may be reduced with 3DSABR or IMRT techniques, while conformality is increased with IMRT or CK. (Source: Radiation Oncology)

Image‐guided dose‐escalated intensity‐modulated radiation therapy for prostate cancer: treating to doses beyond 78 Gy

BJU International — Fri, 28 Oct 2011 04:00:00 +0100

CONCLUSION• Doses >78 Gy delivered using daily image guidance and IMRT are well tolerated, and by 3 months short‐term side‐effects have normalized for the majority of patients. (Source: BJU International)

JCOG Radiation Therapy Study Group: History and Achievements

Japanese Journal of Clinical Oncology — Tue, 25 Oct 2011 04:00:00 +0100

The Radiation Therapy Study Group (RTSG) of the Japan Clinical Oncology Group (JCOG) was established in 2003. The missions of this group are to develop new standards of care with innovative, advanced technology radiation therapy, both for single- and multi-modality cancer treatment, and to improve radiation therapy quality and outcomes of JCOG trials conducted by other organ-oriented groups. In 2004, the first RTSG trial, a Phase II study of stereotactic body radiation therapy for Stage IA non-small cell lung cancer (JCOG 0403), was initiated. Four other trials are currently open for accrual. JCOG 0702 is a Phase I study of stereotactic body radiation therapy in patients with T2N0M0 non-small cell lung cancer. JCOG 0701 is a Phase III study comparing accelerated fractionation with conventi...

Docetaxel, cisplatin and 5-fluorouracil-based induction chemotherapy followed by intensity-modulated radiotherapy concurrent with cisplatin in locally advanced EBV-related nasopharyngeal cancer

Annals of Oncology — Mon, 24 Oct 2011 04:00:00 +0100

Conclusions: In this high-stage nonendemic cancer population, TPF followed by high-dose cisplatin IMRT was promising; this treatment approach deserves evaluation in randomized trials. (Source: Annals of Oncology)

Total error shift patterns for daily CT on rails image-guided radiotherapy to the prostate bed

Radiation Oncology — Mon, 24 Oct 2011 04:00:00 +0100

Conclusions: The overall daily total error shift pattern for these 17 patients simulated with an empty bladder, and treated with CT on rails IGRT was predominantly systematic. Despite this, the temporal vector trends showed complex behaviors and unpredictable changes in magnitude and direction. These findings highlight the importance of using daily IGRT in post-prostatectomy patients. (Source: Radiation Oncology)

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Planning analysis for locally advanced lung cancer: dosimetric and efficiency comparisons between intensity-modulated radiotherapy (IMRT), single-arc/partial-arc volumetric modulated arc therapy (SA/PA-VMAT)

Radiation Oncology — Fri, 21 Oct 2011 04:00:00 +0100

Purpose: To analyze the differences between the intensity-modulated radiotherapy (IMRT), single/partial-arc volumetric modulated arc therapy (SA/PA-VMAT) techniques in treatment planning for locally advanced lung cancer.Methods and materials: 12 patients were retrospectively studied. In each patient's case, several parameters were analyzed based on the dose-volume histograms (DVH) of the IMRT, SA/PA-VMAT plans respectively. Also, each plan was delivered to a phantom for time comparison. Results: The SA-VMAT plans showed the superior target dose coverage, although the minimum/mean/maximum doses to the target were similar. For the total and contralateral lungs, the higher V5/10, lower V20/30 and mean lung dose (MLD) were observed in the SA/PA-VMAT plans (p (Source: Radiation Oncology)

Prone Hypofractionated Whole-Breast Radiotherapy Without a Boost to the Tumor Bed: Comparable Toxicity of IMRT Versus a 3D Conformal Technique

International Journal of Radiation Oncology * Biology * Physics — Fri, 21 Oct 2011 04:00:00 +0100

Conclusion: Hypofractionated breast radiotherapy is well tolerated when treating patients in the prone position, even among those with large breast volumes. Breast IMRT significantly improves dosimetry but yields only a modest but confirmed benefit in terms of toxicities. If a concurrent boost to the tumor bed is not required, a conformal 3D-CRT approach can adequately deliver prone whole-breast hypofractionation radiotherapy. (Source: International Journal of Radiation Oncology * Biology * Physics)

The effect of 6 and 15 MV on intensity-modulated radiation therapy prostate cancer treatment: plan evaluation, tumour control probability and normal tissue complication probability analysis, and the theoretical risk of secondary induced malignancies.

The British Journal of Radiology — Tue, 18 Oct 2011 04:00:00 +0100

Conclusion: The choice to treat using IMRT at 15 MV should not be excluded, but should be based on risk versus benefit, considering the age and life expectancy of the patient together with the relative risk of radiation-induced cancer and NTCPs. PMID: 22010028 [PubMed - as supplied by publisher] (Source: The British Journal of Radiology)

Shinji Takahashi, M.D. (1912–1985): pioneer in early development toward CT and IMRT

Radiological Physics and Technology — Thu, 13 Oct 2011 15:47:12 +0100

Content Type Journal ArticleCategory EditorialPages 1-4DOI 10.1007/s12194-011-0131-4Authors Kunio Doi, Emeritus Professor, Department of Radiology, University of Chicago, Chicago, IL, USAKozo Morita, Aichi Cancer Center Hospital, Nagoya, JapanSadayuki Sakuma, Emeritus Professor, Nagoya University, Nagoya, JapanMasaki Takahashi, Director, Nagoya Clinical Center, Nagoya, Japan Journal Radiological Physics and TechnologyOnline ISSN 1865-0341Print ISSN 1865-0333 (Source: Radiological Physics and Technology)

Baseline Serum Lactate Dehydrogenase Levels for Patients Treated With Intensity-Modulated Radiotherapy for Nasopharyngeal Carcinoma: A Predictor of Poor Prognosis and Subsequent Liver Metastasis

International Journal of Radiation Oncology * Biology * Physics — Thu, 13 Oct 2011 04:00:00 +0100

Purpose: To evaluate the prognostic value of baseline serum lactate dehydrogenase (LDH) levels in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy (IMRT).Methods and Materials: Cases of NPC (n = 465) that involved treatment with IMRT with or without chemotherapy were retrospectively analyzed.Results: The mean (±SD) and median baseline serum LDH levels for this cohort were 172.77 ± 2.28 and 164.00 IU/L, respectively. Levels of LDH were significantly elevated in patients with locoregionally advanced disease (p = 0.016). Elevated LDH levels were identified as a prognostic factor for rates of overall survival (OS), disease-free survival (DFS), and distant metastasis-free survival (DMFS), with p values (Source: International Journal of Radiation Oncol...

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[Radiotherapy of prostate cancer.]

Der Radiologe — Wed, 12 Oct 2011 04:00:00 +0100

This article summarizes the essential publications on definitive and adjuvant radiotherapy and discusses the additional use of androgen deprivation and WPRT. PMID: 21987210 [PubMed - as supplied by publisher] (Source: Der Radiologe)

Comparison of three-dimensional versus intensity-modulated radiotherapy techniques to treat breast and axillary level III and supraclavicular nodes in a prone versus supine position

Radiotherapy and Oncology — Wed, 12 Oct 2011 04:00:00 +0100

Conclusions: Traditional 3DCRT plans provide inadequate nodal coverage. Prone IMRT technique resulted in optimal target coverage and reduced ipsilateral lung V20. (Source: Radiotherapy and Oncology)

Phase II study of induction chemotherapy with TPF followed by radioimmunotherapy with Cetuximab and intensity-modulated radiotherapy (IMRT) in combination with a carbon ion boost for locally advanced tumours of the oro-, hypopharynx and larynx--TPF-C-HIT.

Methods of Information in Medicine — Mon, 10 Oct 2011 22:20:02 +0100

DISCUSSION: The primary objective of TPF-C-HIT is to evaluate efficacy and toxicity of cetuximab in combination with combined IMRT/carbon ion therapy following TPF induction in locally advanced SCCHN. PMID: 21595970 [PubMed - indexed for MEDLINE] (Source: Methods of Information in Medicine)

Comparison of three-dimensional versus intensity-modulated radiotherapy techniques to treat breast and axillary level III and supraclavicular nodes in a prone versus supine position.

Mon, 10 Oct 2011 04:00:00 +0100

CONCLUSIONS: Traditional 3DCRT plans provide inadequate nodal coverage. Prone IMRT technique resulted in optimal target coverage and reduced ipsilateral lung V20. PMID: 21993404 [PubMed - as supplied by publisher] (Source: Radiotherapy and Oncology : journal of the European Society for Therapeutic Radiology and Oncology)

Study of intensity-modulated photon-electron radiation therapy using digital phantoms.

Physics in Medicine and Biology — Sat, 08 Oct 2011 10:45:42 +0100

Authors: Ge Y, Faddegon BA Abstract Intensity-modulated photon-electron radiation therapy (IMPERT) takes advantage of the high conformity of photon intensity-modulated radiation therapy (IMRT) and low distal dose of electrons to reduce the total energy delivered to healthy tissue, potentially reducing serious side effects including secondary malignancies. This theoretical study was undertaken to elucidate basic principles of IMPERT planning and to help quantify the advantage of IMPERT over photon IMRT. Plans using 6 MV x-rays alone (IMRT) or in combination with 6-21 MeV electron beams (IMPERT) were developed for digital cylindrical water phantoms that included an organ at risk (OAR) situated 0.25 cm below a 5 cm thick planning target volume (PTV), with the top of the PTV positioned...

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Florida hospital selects RaySearch treatment planning system

Hospital Management — Sat, 08 Oct 2011 05:27:02 +0100

Baptist Hospital of Miami, part of healthcare organisation Baptist Health South Florida, has chosen RaySearch Laboratories' RayStation treatment planning system for treatments, such as intensity-modulated radiation therapy (IMRT).Post to:Delicious Digg reddit Facebook StumbleUpon (Source: Hospital Management)

Improved Accuracy Of IMRT Delivery In Post-Prostatectomy Patients

Health News from Medical News Today — Fri, 07 Oct 2011 08:00:00 +0100

Prostate cancer is the most common cancer in men in the United States, as well as the second leading cause of cancer-related deaths in this population. Many of these patients undergo surgical removal of their prostate, followed by radiation therapy applied to their prostate bed - the space where the prostate was once situated. The most common technique of post-prostatectomy radiation is Intensity Modulated Radiation Therapy (IMRT), in which radiation beams closely conform to the area of interest while sparing normal adjacent healthy structures... (Source: Health News from Medical News Today)

Intensity-Modulated Radiotherapy for Squamous Cell Carcinoma of the Anal Canal: Efficacy of a Low Daily Dose to Clinically Negative Regions

Radiation Oncology — Thu, 06 Oct 2011 04:00:00 +0100

Conclusions: Our data support using doses between 1.50 and 1.80 Gy/day to clinically uninvolved regions. (Source: Radiation Oncology)

IMRT offers fewer harmful rectal side effects than 3-D CRT

Modern Medicine — Thu, 06 Oct 2011 04:00:00 +0100

Men with localized prostate cancer treated with intensity-modulated radiation therapy (IMRT) have more than a quarter (26%) fewer late bowel and rectal side effects and a statistically improved lower dose of radiation to the bladder and rectum, compared with those who undergo 3-D conformal radiotherapy (3-D CRT), according to a randomized study presented at the American Society for Radiation Oncology annual meeting in Miami Beach, FL. (Source: Modern Medicine)

Fox Chase researchers improve accuracy of IMRT delivery in post-prostatectomy patients

EurekAlert! - Medicine and Health — Wed, 05 Oct 2011 04:00:00 +0100

(Fox Chase Cancer Center) Prostate cancer is the most common cancer in men in the United States, as well as the second leading cause of cancer-related deaths in this population. Many of these patients undergo surgical removal of their prostate, followed by radiation therapy applied to their prostate bed -- the space where the prostate was once situated. (Source: EurekAlert! - Medicine and Health)

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Long-term outcomes of three-dimensional conformal radiation therapy combined with neoadjuvant hormonal therapy for Japanese patients with T1c-T2N0M0 prostate cancer

International Journal of Clinical Oncology — Tue, 04 Oct 2011 05:56:59 +0100

Conclusions The PSA control rates in our series of Japanese patients with stage T1c-T2N0M0 prostate cancer treated with the standard dose of 3D-CRT combined with NAHT seemed at least comparable to those reported from Western countries; as well, the patients had excellent outcomes. The present outcomes can be used as basic data for evaluating the impact of dose escalation with intensity-modulated radiation therapy for Japanese patients with prostate cancer in the future. Content Type Journal ArticleCategory Original ArticlePages 1-7DOI 10.1007/s10147-011-0326-zAuthors Takashi Mizowaki, Department of Radiation Oncology and Image-applied Therapy, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507 JapanKenji Takayama, Depar...

RaySearch Laboratories AB: Florida hospital selects RayStation(R)

HSMN NewsFeed — Mon, 03 Oct 2011 13:07:25 +0100

STOCKHOLM--(Healthcare Sales & Marketing Network)-- RaySearch Laboratories AB (STO:RAYB.st ) has received an order for its RayStation® treatment planning system from Baptist Hospital of Miami. Baptist Hospital of Miami is a part of Baptist Health So... Devices, OncologyRaySearch Laboratories, RayStation, treatment planning system, IMRT, VMAT (Source: HSMN NewsFeed)

Application of a spacer gel to optimize three-dimensional conformal and intensity modulated radiotherapy for prostate cancer

Radiotherapy and Oncology — Mon, 03 Oct 2011 04:00:00 +0100

Abstract: Background and purpose: The aim was to evaluate the impact of a spacer gel on the dose distribution, applying three-dimensional conformal (3D CRT) and intensity modulated radiotherapy (IMRT) planning techniques.Material and methods: The injection of a spacer gel (10ml SpaceOAR™) was performed between the prostate and rectum under transrectal ultrasound guidance in 18 patients with prostate cancer. 3D CRT and IMRT treatment plans were compared based on CT before and after injection (78Gy prescription dose).Results: In contrast to the PTV and bladder, significant advantages (p50% for both IMRT and 3D CRT. Significantly (p (Source: Radiotherapy and Oncology)

Clinical introduction of a linac head-mounted 2D detector array based quality assurance system in head and neck IMRT

Radiotherapy and Oncology — Mon, 03 Oct 2011 04:00:00 +0100

Conclusions: Agreement of COMPASS QA results with film based QA supports its clinical introduction for a phantom geometry. A standard MLC calibration check is sensitive to (Source: Radiotherapy and Oncology)

A comparison of several modulated radiotherapy techniques for head and neck cancer and dosimetric validation of VMAT

Radiotherapy and Oncology — Mon, 03 Oct 2011 04:00:00 +0100

Conclusion: All treatment paradigms produced plans of excellent quality and dosimetric accuracy with IMRT providing best OAR sparing and VMAT being the most efficient treatment option in our comparison of treatment plans with high complexity. (Source: Radiotherapy and Oncology)

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Dosimetric comparison of helical tomotherapy, RapidArc, and a novel IMRT & Arc technique for esophageal carcinoma

Radiotherapy and Oncology — Mon, 03 Oct 2011 04:00:00 +0100

Abstract: Purpose: To compare radiotherapy treatment plans for mid- and distal-esophageal cancer with primary involvement of the gastroesophageal (GE) junction using a novel IMRT & Arc technique (IMRT & Arc), helical tomotherapy (HT), and RapidArc (RA1 and RA2).Methods and materials: Eight patients treated on HT for locally advanced esophageal cancer with radical intent were re-planned for RA and IMRT&Arc. RA plans employed single and double arcs (RA1 and RA2, respectively), while IMRT&Arc plans had four fixed-gantry IMRT fields and a conformal arc. Dose-volume histogram statistics, dose uniformity, and dose homogeneity were analyzed to compare treatment plans.Results: RA2 plans showed significant improvement over RA1 plans in terms of OAR dose and PTV dose uniformity and homogeneity. HT p...

Dosimetric comparison of helical tomotherapy, RapidArc, and a novel IMRT & Arc technique for esophageal carcinoma.

Sat, 01 Oct 2011 04:00:00 +0100

CONCLUSION: The IMRT&Arc technique is a good option for treating esophageal cancer with thoracic involvement. It achieved optimal low dose to the lungs and heart with acceptable PTV coverage. HT is a good option for treating esophageal cancer with little thoracic involvement as it achieves superior dose conformality and uniformity. The RA2 technique provided for improved treatment plans using additional arcs with low doses to the lungs at the cost of increased heart dose. Plan quality could still be improved through the use of additional arcs. PMID: 21962823 [PubMed - as supplied by publisher] (Source: Radiotherapy and Oncology : journal of the European Society for Therapeutic Radiology and Oncology)

Toward IMRT 2D dose modeling using artificial neural networks: A feasibility study.

Medical Physics — Sat, 01 Oct 2011 04:00:00 +0100

Conclusions: An artificial neural network has been developed to convert fluence maps to corresponding dose maps. The feasibility and potential of an artificial neural network to replicate complex convolution kernels in the TPS for IMRT dose calculations have been demonstrated. PMID: 21992395 [PubMed - in process] (Source: Medical Physics)

Moving from gamma passing rates to patient DVH-based QA metrics in pretreatment dose QA.

Medical Physics — Sat, 01 Oct 2011 04:00:00 +0100

Conclusions: Gamma passing rate, even if calculated based on patient dose grids, has generally weak correlation to critical patient DVH errors. However, the PDP algorithm was shown to accurately predict the DVH impact using conventional planar QA results. Using patient-DVH-based metrics IMRT QA allows per-patient dose QA to be based on metrics that are both sensitive and specific. Further studies are now required to analyze new processes and action levels associated with DVH-based metrics to ensure effectiveness and practicality in the clinical setting. PMID: 21992366 [PubMed - as supplied by publisher] (Source: Medical Physics)