31,679 results match your criteria beam radiotherapy

The Impact of Radiotherapy Delay in Breast Conservation Patients Not Receiving Chemotherapy and the Rationale for Dichotomizing the Radiation Oncology Time-Dependent Standard into Two Quality Measures.

Ann Surg Oncol 2021 Jul 29. Epub 2021 Jul 29.

The Data Working Group of the National Accreditation Program for Breast Centers, Chicago, IL, USA.

Introduction: The Commission on Cancer/National Quality Forum breast radiotherapy quality measure establishes that for women < 70 years, adjuvant radiotherapy after breast conserving surgery (BCS) should be started < 1 year from diagnosis. This was intended to prevent accidental radiotherapy omission or delay due to a long interval between surgery and chemotherapy completion, when radiation is delivered. However, the impact on patients not receiving chemotherapy, who proceed from surgery directly to radiotherapy, remains unknown. Read More

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Focal Therapy for Prostate Cancer: Complications and Their Treatment.

Front Surg 2021 12;8:696242. Epub 2021 Jul 12.

Department of Urology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.

Focal therapy is a modern alternative to selectively treat a specific part of the prostate harboring clinically significant disease while preserving the rest of the gland. The aim of this therapeutic approach is to retain the oncological benefit of active treatment and to minimize the side-effects of common radical treatments. The oncological effectiveness of focal therapy is yet to be proven in long-term robust trials. Read More

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Towards real-time PGS range monitoring in proton therapy of prostate cancer.

Sci Rep 2021 Jul 28;11(1):15331. Epub 2021 Jul 28.

German Cancer Research Center - DKFZ, Heidelberg, Germany.

Proton therapy of prostate cancer (PCPT) was linked with increased levels of gastrointestinal toxicity in its early use compared to intensity-modulated radiation therapy (IMRT). The higher radiation dose to the rectum by proton beams is mainly due to anatomical variations. Here, we demonstrate an approach to monitor rectal radiation exposure in PCPT based on prompt gamma spectroscopy (PGS). Read More

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Can patients with low-risk prostate cancer really benefit from radical treatment?: A systematic review and network meta-analysis.

Andrologia 2021 Jul 28:e14122. Epub 2021 Jul 28.

Department of Urology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Dongcheng District, Beijing, China.

Radical prostatectomy, radiotherapy and active surveillance are three widely used treatment options for patients with low-risk prostate cancer, but the relative effects are controversial. We searched PubMed, Embase and Web of Science until June 2020, focusing on the studies comparing the effect of radical prostatectomy, radiotherapy and active surveillance in patients with low-risk prostate cancer. Through the random-effects model, dichotomous data were extracted and summarised by odds ratio with a 95% confidence interval. Read More

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FLASH radiotherapy with carbon ion beams.

Med Phys 2021 Jul 28. Epub 2021 Jul 28.

GSI Helhmoltzzentrum für Schwerionenforschung, Biophysics Department, Darmstadt, Germany.

FLASH radiotherapy is considered a new potential breakthrough in cancer treatment. Ultra-high dose rates (>40 Gy/s) have been shown to reduce toxicity in the normal tissue without compromising tumor control, resulting in a widened therapeutic window. These high dose rates are more easily achievable in the clinic with charged particles, and clinical trials are indeed ongoing using electrons or protons. Read More

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Interstitial Brachytherapy for Orbital Sebaceous Carcinoma.

Ophthalmic Plast Reconstr Surg 2021 Jul 27. Epub 2021 Jul 27.

The Department of Ocular Tumor, Orbital Disease and Ophthalmic Radiation Therapy, The New York Eye Cancer Center, New York, New York, U.S.A. The Departments of Radiation Oncology and Ophthalmology, The New York Eye and Ear Infirmary of Mount Sinai, New York, New York, U.S.A.

Sebaceous carcinoma is characterized by its aggressive local tumor behavior and ability to metastasize. Small periocular sebaceous carcinoma are typically treated by excision with cryotherapy. Larger tumors often require adjuvant external beam radiotherapy (EBRT) and/or exenteration surgery. Read More

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Improving efficiency in the radiation management of multiple brain metastases using a knowledge-based planning solution for single-isocentre volumetric modulated arc therapy (VMAT) technique.

J Med Radiat Sci 2021 Jul 26. Epub 2021 Jul 26.

Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, New South Wales, Australia.

Introduction: This study aimed to develop a single-isocentre volumetric modulated arc therapy (si-VMAT) technique for multiple brain metastases using knowledge-based planning software, comparing it with a multiple-isocentre stereotactic radiosurgery (mi-SRS) planning approach.

Methods: Twenty-six si-VMAT plans were created and uploaded into RapidPlan (RP) to create a si-VMAT model. Ten patients, with 2 to 6 metastases (mets), were planned with a si-VMAT technique utilising RP, and a mi-SRS technique on Brainlab iPlan. Read More

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Short Androgen Suppression and Radiation Dose Escalation in Prostate Cancer: 12-Year Results of EORTC Trial 22991 in Patients With Localized Intermediate-Risk Disease.

J Clin Oncol 2021 Jul 26:JCO2100855. Epub 2021 Jul 26.

European Organization for Research and Treatment of Cancer, Brussels, Belgium.

Purpose: The European Organisation for Research and Treatment of Cancer (EORTC) trial 22991 (NCT00021450) showed that 6 months of concomitant and adjuvant androgen suppression (AS) improves event- (EFS, Phoenix) and clinical disease-free survival (DFS) of intermediate- and high-risk localized prostatic carcinoma, treated by external-beam radiotherapy (EBRT) at 70-78 Gy. We report the long-term results in intermediate-risk patients treated with 74 or 78 Gy EBRT, as per current guidelines.

Patient And Methods: Of 819 patients randomly assigned between EBRT or EBRT plus AS started on day 1 of EBRT, 481 entered with intermediate risk (International Union Against Cancer TNM 1997 cT1b-c or T2a with prostate-specific antigen (PSA) ≥ 10 ng/mL or Gleason ≤ 7 and PSA ≤ 20 ng/mL, N0M0) and had EBRT planned at 74 (342 patients, 71. Read More

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Patient position verification in magnetic-resonance imaging only radiotherapy of anal and rectal cancers.

Phys Imaging Radiat Oncol 2021 Jul 18;19:72-77. Epub 2021 Jul 18.

Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds, UK.

Background And Purpose: Magnetic resonance (MR)-only treatment pathways require either the MR-simulation or synthetic-computed tomography (sCT) as an alternative reference image for cone beam computed tomography (CBCT) patient position verification. This study assessed whether using T2 MR or sCT as CBCT reference images introduces systematic registration errors as compared to CT for anal and rectal cancers.

Materials And Methods: A total of 32 patients (18 rectum,14 anus) received pre-treatment CT- and T2 MR- simulation. Read More

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Characterization of automatic treatment planning approaches in radiotherapy.

Phys Imaging Radiat Oncol 2021 Jul 13;19:60-65. Epub 2021 Jul 13.

Department of Radiation Oncology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.

Background And Purpose: Automatic approaches are widely implemented to automate dose optimization in radiotherapy treatment planning. This study systematically investigates how to configure automatic planning in order to create the best possible plans.

Materials And Methods: Automatic plans were generated using protocol based automatic iterative optimization. Read More

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Risk of radiation-induced second malignant neoplasms from photon and proton radiotherapy in paediatric abdominal neuroblastoma.

Phys Imaging Radiat Oncol 2021 Jul 9;19:45-52. Epub 2021 Jul 9.

Centre for Medical Image Computing, Department of Medical Physics and Biomedical Engineering, University College London, London, UK.

Background And Purpose: State-of-the-art radiotherapy modalities have the potential of reducing late effects of treatment in childhood cancer survivors. Our aim was to investigate the carcinogenic risk associated with 3D conformal (photon) radiation (3D-CRT), intensity modulated arc therapy (IMAT) and pencil beam scanning proton therapy (PBS-PT) in the treatment of paediatric abdominal neuroblastoma.

Materials And Methods: The risk of radiation-induced second malignant neoplasm (SMN) was estimated using the concept of organ equivalent dose (OED) for eleven organs (lungs, rectum, colon, stomach, small intestine, liver, bladder, skin, central nervous system (CNS), bone, and soft tissues). Read More

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Quantification of the uncertainties within the radiotherapy dosimetry chain and their impact on tumour control.

Phys Imaging Radiat Oncol 2021 Jul 28;19:33-38. Epub 2021 Jun 28.

Department of Chemical and Process Engineering, University of Surrey, Guildford, UK.

Background And Purpose: Dose delivered during radiotherapy has uncertainty arising from a number of sources including machine calibration, treatment planning and delivery and can impact outcomes. Any systematic uncertainties will impact all patients and can continue for extended periods. The impact on tumour control probability (TCP) of the uncertainties within the radiotherapy calibration process has been assessed. Read More

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Automatic 3D Monte-Carlo-based secondary dose calculation for online verification of 1.5 T magnetic resonance imaging guided radiotherapy.

Phys Imaging Radiat Oncol 2021 Jul 21;19:6-12. Epub 2021 Jun 21.

Section for Biomedical Physics, Department of Radiation Oncology, University Hospital and Medical Faculty, Eberhard Karls University of Tübingen, Tübingen, Germany.

Background And Purpose: Hybrid magnetic resonance linear accelerator (MR-Linac) systems represent a novel technology for online adaptive radiotherapy. 3D secondary dose calculation (SDC) of online adapted plans is required to assure patient safety. Currently, no 3D-SDC solution is available for 1. Read More

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Complete resolution of a giant multilocular prostatic cystadenoma following androgen deprivation therapy: an illustrative case report.

Oxf Med Case Reports 2021 Jul 21;2021(7):omab053. Epub 2021 Jul 21.

Department of Radiology, Addenbrooke's Hospital and University of Cambridge, Cambridge CB2 0QQ, UK.

Giant multilocular prostatic cystadenoma (GMPC) is a rare benign pelvic mass for which complete surgical resection is an accepted treatment of choice. This report presents the first case of complete resolution of GMPC following a 3-year course of luteinising hormone-releasing hormone agonist alongside external beam radiotherapy for the concurrent treatment of unfavorable intermediate-risk prostate cancer. In addition to illustrating the imaging features of the effect of androgen deprivation therapy (ADT) and radiotherapy on GMPC regression, this case provides evidence for considering ADT as an alternative, noninvasive GMPC treatment option in patients in whom surgical treatment is either contraindicated or can be made less invasive by reducing the size of GMPC prior to its removal. Read More

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Low-Diffusion Fricke Gel Dosimeters with Core-Shell Structure Based on Spatial Confinement.

Materials (Basel) 2021 Jul 14;14(14). Epub 2021 Jul 14.

College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211100, China.

The diffusion of ferric ions is an important challenge to limit the application of Fricke gel dosimeters in accurate three-dimensional dose verification of modern radiotherapy. In this work, low-diffusion Fricke gel dosimeters, with a core-shell structure based on spatial confinement, were constructed by utilizing microdroplet ultrarapid freezing and coating technology. Polydimethylsiloxane (PDMS), with its excellent hydrophobicity, was coated on the surface of the pellets. Read More

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Focused Ion Microbeam Irradiation Induces Clustering of DNA Double-Strand Breaks in Heterochromatin Visualized by Nanoscale-Resolution Electron Microscopy.

Int J Mol Sci 2021 Jul 16;22(14). Epub 2021 Jul 16.

Department of Radiation Oncology, Saarland University Hospital, 66421 Homburg, Germany.

Background: Charged-particle radiotherapy is an emerging treatment modality for radioresistant tumors. The enhanced effectiveness of high-energy particles (such as heavy ions) has been related to the spatial clustering of DNA lesions due to highly localized energy deposition. Here, DNA damage patterns induced by single and multiple carbon ions were analyzed in the nuclear chromatin environment by different high-resolution microscopy approaches. Read More

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Intensity Modulated Proton Beam Therapy versus Volumetric Modulated Arc Therapy for Patients with Nasopharyngeal Cancer: A Propensity Score-Matched Study.

Cancers (Basel) 2021 Jul 16;13(14). Epub 2021 Jul 16.

Proton and Radiation Therapy Center, Department of Radiation Oncology, Linkou Chang Gung Memorial Hospital, Chang Gung University, Taoyuan 333, Taiwan.

(1) Background: We compared the outcomes of patients with nasopharyngeal carcinoma treated with IMPT and VMAT. (2) Methods: We performed a retrospective propensity score matching analysis (1:1) of patients treated with IMPT (years: 2016-2018) and VMAT (2014-2018). Survival was estimated using the Kaplan-Meier method. Read More

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Quantitative Assessment of 3D Dose Rate for Proton Pencil Beam Scanning FLASH Radiotherapy and Its Application for Lung Hypofractionation Treatment Planning.

Cancers (Basel) 2021 Jul 15;13(14). Epub 2021 Jul 15.

New York Proton Center, New York, NY 10035, USA.

To quantitatively assess target and organs-at-risk (OAR) dose rate based on three proposed proton PBS dose rate metrics and study FLASH intensity-modulated proton therapy (IMPT) treatment planning using transmission beams. An in-house FLASH planning platform was developed to optimize transmission (shoot-through) plans for nine consecutive lung cancer patients previously planned with proton SBRT. Dose and dose rate calculation codes were developed to quantify three types of dose rate calculation methods (dose-averaged dose rate (DADR), average dose rate (ADR), and dose-threshold dose rate (DTDR)) based on both phantom and patient treatment plans. Read More

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Neurocognitive Outcomes in Pediatric Patients Following Brain Irradiation.

Cancers (Basel) 2021 Jul 15;13(14). Epub 2021 Jul 15.

Department of Radiation Oncology, Heidelberg University Hospital, 69120 Heidelberg, Germany.

Advanced radiation techniques can reduce the severity of neurocognitive sequelae in young brain tumor patients. In the present analysis, we sought to compare neurocognitive outcomes after proton irradiation with patients who underwent photon radiotherapy (RT) and surgery. Neurocognitive outcomes were evaluated in 103 pediatric brain tumor patients (proton RT = 26, photon RT = 30, surgery = 47) before and after treatment. Read More

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Clinical Outcomes of Pencil Beam Scanning Proton Therapy in Locally Advanced Non-Small Cell Lung Cancer: Propensity Score Analysis.

Cancers (Basel) 2021 Jul 13;13(14). Epub 2021 Jul 13.

Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea.

This study compared the efficacy and safety of pencil beam scanning proton therapy (PBSPT) versus intensity-modulated (photon) radiotherapy (IMRT) in patients with stage III non-small cell lung cancer (NSCLC). We retrospectively reviewed 219 patients with stage III NSCLC who received definitive concurrent chemoradiotherapy between November 2016 and December 2018. Twenty-five patients (11. Read More

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Novel Prognostic Index of High-Risk Prostate Cancer Using Simple Summation of Very High-Risk Factors.

Cancers (Basel) 2021 Jul 12;13(14). Epub 2021 Jul 12.

Department of Radiology, Ujitakeda Hospital, Uji-City 611-0021, Japan.

This study aimed to examine the role of very high-risk (VHR) factors (T3b-4 and Gleason score 9-10) for prognosis of clinically localized high-risk prostate cancer. We reviewed multi-institutional retrospective data of 1413 patients treated with radiotherapy (558 patients treated with external beam radiotherapy (EBRT) and 855 patients treated with brachytherapy (BT) ± EBRT. We introduced an index by simple summation of the number of VHR factors-VHR-0, VHR-1, and VHR-2. Read More

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Estimating the modulating effect of lung tissue in particle therapy using a clinical CT voxel histogram analysis.

Phys Med Biol 2021 Jul 23. Epub 2021 Jul 23.

Department of Radiotherapy and Radiooncology, University Medical Center Giessen-Marburg, Marburg, GERMANY.

To treat lung tumours with particle therapy, different additional tasks and challenges in treatment planning and application have to be addressed thoroughly. One of these tasks is the quantification and consideration of the Bragg peak degradation due to lung tissue: As lung is an heterogeneous tissue, the Bragg peak is broadened when particles traverse the microscopic alveoli. These are not fully resolved in clinical CT images and thus, the effect is not considered in the dose calculation. Read More

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Intra-fractional per-beam adaptive workflow to mitigate the need for a rotating gantry during MRI-guided proton therapy.

Phys Med Biol 2021 Jul 23. Epub 2021 Jul 23.

Department of Radiotherapy, University Medical Center Utrecht Imaging Division, Utrecht, NETHERLANDS.

The integration of real-time magnetic resonance imaging (MRI)-guidance and proton therapy would potentially improve the proton dose steering capability by reducing daily uncertainties due to anatomical variations. The use of a fixed beamline coupled with an axial patient couch rotation would greatly simplify the proton delivery with MRI-guidance. Nonetheless, it is mandatory to assure that the plan quality is not deteriorated by the anatomical deformations due to patient rotation. Read More

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Additional Value of 18F-FDOPA Amino Acid Analog Radiotracer to Irradiation Planning Process of Patients With Glioblastoma Multiforme.

Front Oncol 2021 6;11:699360. Epub 2021 Jul 6.

Doctoral School of Health Sciences, University of Pécs, Pécs, Hungary.

Purpose: To investigate the added value of 6-(18F]-fluoro-L-3,4-dihydroxyphenylalanine (FDOPA) PET to radiotherapy planning in glioblastoma multiforme (GBM).

Methods: From September 2017 to December 2020, 17 patients with GBM received external beam radiotherapy up to 60 Gy with concurrent and adjuvant temozolamide. Target volume delineations followed the European guideline with a 2-cm safety margin clinical target volume (CTV) around the contrast-enhanced lesion+resection cavity on MRI gross tumor volume (GTV). Read More

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Validation of proton dose calculation on scattercorrected 4D cone beam computed tomographyusing a porcine lung phantom.

Phys Med Biol 2021 Jul 22. Epub 2021 Jul 22.

Department of Radiation Oncology, University Hospital Munich, Munich, Bavaria, GERMANY.

Proton therapy treatment for lungs remains challenging as images enabling the detection of inter- and intra-fractional motion, which could be used for proton dose adaptation, are not readily available. 4D computed tomography (4DCT) provides high image quality but is rarely available in-room, while in-room 4D cone beam computed tomography (4DCBCT) suffers from image quality limitations stemming mostly from scatter detection. This study investigated the feasibility of using virtual 4D computed tomography (4DvCT) as a prior for a phase-per-phase scatter correction algorithm yielding a 4D scatter corrected cone beam computed tomography image (4DCBCT), which can be used for proton dose calculation. Read More

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HEDOS - a computational tool to assess radiation dose to circulating blood cells during external beam radiotherapy based on whole-body blood flow simulations.

Phys Med Biol 2021 Jul 22. Epub 2021 Jul 22.

Division of Radiation Biophysics, Department of Radiation Oncology, , Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, UNITED STATES.

We have developed a time-dependent computational framework, HEDOS (HEmatological DOSe), to estimate dose to circulating blood cells from radiation therapy treatment fields for any treatment site. Two independent dynamic models were implemented in HEDOS: one describing the spatiotemporal distribution of blood particles (BPs) in organs and the second describing the time-dependent radiation field delivery. A whole-body blood flow network based on blood volumes and flow rates from ICRP Publication 89 was simulated to produce the spatiotemporal distribution of BPs in organs across the entire body using a discrete-time Markov process. Read More

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Seminal vesicle intrafraction motion during the delivery of radiotherapy sessions on a 1.5 T MR-Linac.

Radiother Oncol 2021 Jul 19. Epub 2021 Jul 19.

University Medical Center Utrecht, Department of Radiotherapy, Utrecht 3508 GA, The Netherlands.

PurposeTo evaluate seminal vesicle (SV) intrafraction motion using cinematic magnetic resonance imaging (cine-MR) during the delivery of online adaptive MR-Linac radiotherapy fractions, in preparation of MR-guided extremely hypofractionated radiotherapy for intermediate to high-risk prostate cancer patients.Material and MethodsFifty prostate cancer patients were treated with 5 x 7.25 Gy on a 1. Read More

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Intensity-modulated radiation therapy and doxorubicin in thyroid cancer: A prospective phase 2 trial.

Cancer 2021 Jul 22. Epub 2021 Jul 22.

Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York.

Background: The use of external-beam radiotherapy for locally advanced nonanaplastic thyroid cancer remains controversial. This prospective study evaluated the efficacy and tolerability of intensity-modulated radiation therapy (IMRT) with or without concurrent chemotherapy in patients with locally advanced thyroid cancer.

Methods: The authors conducted a nonrandomized phase 2 trial of IMRT with or without concurrent doxorubicin in patients with gross residual or unresectable nonanaplastic thyroid carcinoma (ClinicalTrials. Read More

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Factors affecting urinary frequency after low-dose-rate brachytherapy for prostate cancer.

Low Urin Tract Symptoms 2021 Jul 20. Epub 2021 Jul 20.

Department of Urology, Nara Medical University, Kashihara, Japan.

Objectives: Lower urinary tract symptoms are transiently exacerbated by low-dose-rate brachytherapy (LDR-BT) for prostate cancer and recover to pretreatment levels 1 year thereafter. Generally, these symptoms are influenced by temperature. We aimed to search for factors affecting the lower urinary tract symptoms after seed implant including seasons. Read More

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The use of collimator angle optimization and jaw tracking for VMAT-based single-isocenter multiple-target stereotactic radiosurgery for up to six targets in the Varian Eclipse treatment planning system.

J Appl Clin Med Phys 2021 Jul 19. Epub 2021 Jul 19.

Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia.

Purpose: Island blocking occurs in single-isocenter multiple-target (SIMT) stereotactic radiotherapy (SRS) whenever targets share multi-leaf collimator (MLC) leaf pairs. This study investigated the effect on plan quality and delivery, of reducing island blocking through collimator angle optimization (CAO). In addition, the effect of jaw tracking in this context was also investigated. Read More

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