5,775 results match your criteria vmat plans

The feasibility of a dose painting procedure to treat prostate cancer based on mpMR images and hierarchical clustering.

Radiat Oncol 2021 Sep 20;16(1):182. Epub 2021 Sep 20.

Department of Aerospace Engineering, Iowa State University, Ames, IA, 50011, USA.

Background: We aimed to assess the feasibility of a dose painting (DP) procedure, known as simultaneous integrated boost intensity modulated radiation Therapy (SIB-IMRT), for treating prostate cancer with dominant intraprostatic lesions (DILs) based on multi-parametric magnetic resonance (mpMR) images and hierarchical clustering with a machine learning technique.

Methods: The mpMR images of 120 patients were used to create hierarchical clustering and draw a dendrogram. Three clusters were selected for performing agglomerative clustering. Read More

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September 2021

Increasing demand on human capital and resource utilization in radiotherapy: The past decade.

Int J Radiat Oncol Biol Phys 2021 Sep 17. Epub 2021 Sep 17.

Department of Oncology, University of Calgary, Calgary AB, Canada; Department of Physics & Astronomy, University of Calgary, Calgary AB, Canada; Tom Baker Cancer Centre, Calgary AB, Canada.

Purpose: To quantify the change resource utilization in radiotherapy in the context of advancing technologies and techniques over the last decade.

Methods And Materials: Prospectively, the time to complete radiotherapy workflow tasks was captured between January 1, 2020 and December 31, 2020. The institutional task workflows are specific to each technique and broadly organized into four categories: 3D conformal radiotherapy (3DCRT), IMRT, VMAT simple, and VMAT complex. Read More

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September 2021

Clinical impact of anisotropic analytical algorithm and Acuros XB dose calculation algorithms for intensity modulated radiation therapy in lung cancer patients.

J Xray Sci Technol 2021 Sep 15. Epub 2021 Sep 15.

Biophysics Department, Faculty of Science, Cairo University, Giza, Egypt.

Objective: To evaluate dose differences predicted between using Anisotropic Analytical Algorithm (AAA) and Acuros XB (AXB) in patients diagnosed with locally advanced non-small cell lung cancer (NSCLC) treated with intensity modulated radiation therapy (IMRT).

Methods: A phantom study was done to evaluate the dose prediction accuracy of AXB and AAA beyond low-density medium by comparing the calculated measurement results. Thirty-two advanced NSCLC patients were subjected to IMRT. Read More

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September 2021

Dosimetric Comparison, Treatment Efficiency Estimation, and Biological Evaluation of Popular Stereotactic Radiosurgery Options in Treating Single Small Brain Metastasis.

Front Oncol 2021 5;11:716152. Epub 2021 Aug 5.

Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China.

Objectives: This study aimed to show the advantages of each stereotactic radiosurgery (SRS) treatment option for single small brain metastasis among Gamma Knife (GK), Cone-based VMAT (Cone-VMAT), and MLC-based CRT (MLC-CRT) plans.

Materials And Methods: GK, Cone-VMAT, and MLC-CRT SRS plans were retrospectively generated for 11 patients with single small brain metastasis whose volume of gross tumor volume (GTV) ranged from 0.18 to 0. Read More

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Treatment planning comparison between dynamic wave arc and volumetric modulated arc therapies for prostate-cancer treatment.

Med Dosim 2021 Sep 16. Epub 2021 Sep 16.

Hiroshima High-Precision Radiotherapy Cancer Center, 3-2-2, Futabanosato, Higashi-ku Hiroshima 732-0057, Japan; Department of Radiation Oncology, Graduate School of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan.

The aim of this study was to compare the quality of dynamic wave arc (DWA) and coplanar volumetric modulated arc therapy (co-VMAT) plans for the treatment of localized prostate cancer. The planning target volume (PTV)-rectum, a section of the PTV comprising the PTV minus that of the rectum, received 78 Gy in 39 fractions as the mean dose to the PTV-rectum. The DWA and co-VMAT plans were generated for each patient using the RayStation treatment planning system for the Vero4DRT system. Read More

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September 2021

Online MR evaluation of inter- and intra-fraction uterus motions and bladder volume changes during cervical cancer external beam radiotherapy.

Radiat Oncol 2021 Sep 17;16(1):179. Epub 2021 Sep 17.

Department of Radiation Oncology Physics and Technology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, No.440 Jiyan road, Huaiyin district, Jinan City, 250117, Shandong Province, China.

Purpose/objective(s): The purpose of the study was to assess the uterus motions and bladder volume changes of fractional movements in cervical sites throughout the external beam radiotherapy (EBRT) treatment.

Materials/methods: A prospective online MR imaging tracking study was conducted in EBRT 43 patients with at least 4 scans during each treatment (before: ultrasound scan, MRI scan, CBCT scan, after: MRI scan) were included. In order to improve the treatment repeatability, each patient was instructed to empty the bladder and drink 500 ml water 1 h before CT simulation and each treatment. Read More

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September 2021

Diaphragm Based Position Verification to Improve Daily Target Dose Coverage in Proton and Photon Radiotherapy Treatment of Distal Esophageal Cancer.

Int J Radiat Oncol Biol Phys 2021 Sep 13. Epub 2021 Sep 13.

Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, The Netherlands.

Purpose: In modern conformal radiotherapy of distal esophageal cancer, target coverage can be affected by variations in the diaphragm position. We investigated if daily position verification (PV) extended by a diaphragm position correction would optimize target dose coverage for esophageal cancer treatment.

Materials And Methods: For fifteen esophageal cancer patients, intensity modulated proton therapy (IMPT) and volumetric modulated arc therapy (VMAT) plans were computed. Read More

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September 2021

Single-isocenter stereotactic non-coplanar arc treatment of 200 patients with brain metastases: multileaf collimator size and setup uncertainties.

Strahlenther Onkol 2021 Sep 15. Epub 2021 Sep 15.

Department of Oncology, Radiotherapy Research Unit (52AA), Herlev & Gentofte Hospital, University of Copenhagen, Borgmester Ib Juuls vej 7, 2730, Herlev, Denmark.

Purpose: The purpose of this study was to evaluate our 2 years' experience with single-isocenter, non-coplanar, volumetric modulated arc therapy (VMAT) for brain metastasis (BM) stereotactic radiosurgery (SRS).

Methods: A total of 202 patients treated with the VMAT SRS solution were analyzed retrospectively. Plan quality was assessed for 5 mm (120) and 2. Read More

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September 2021

Influence of eye movement on lens dose and optic nerve target coverage during craniospinal irradiation.

Clin Transl Radiat Oncol 2021 Nov 29;31:28-33. Epub 2021 Aug 29.

Department of Radiation Oncology, University Medical Center Utrecht, Utrecht, the Netherlands.

Purpose: Optic nerves are part of the craniospinal irradiation (CSI) target volume. Modern radiotherapy techniques achieve highly conformal target doses while avoiding organs-at-risk such as the lens. The magnitude of eye movement and its influence on CSI target- and avoidance volumes are unclear. Read More

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November 2021

Dose rate correction for a silicon diode detector array.

J Appl Clin Med Phys 2021 Sep 14. Epub 2021 Sep 14.

Department of Radiation Oncology, University of Wuerzburg, Wuerzburg, Germany.

Purpose: A signal dependence on dose rate was reported for the ArcCHECK array due to recombination processes within the diodes. The purpose of our work was to quantify the necessary correction and apply them to quality assurance measurements.

Methods: Static 10 × 10 cm 6-MV fields delivered by a linear accelerator were applied to the detector array while decreasing the average dose rate, that is, the pulse frequency, from 500 to 30 MU/min. Read More

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September 2021

Fully automated noncoplanar radiation therapy treatment planning.

Med Phys 2021 Sep 14. Epub 2021 Sep 14.

Department of Radiation Oncology, Stanford University, Stanford, USA.

Purpose: To perform fully automated noncoplanar treatment planning, we propose a method called NC-POPS to produce noncoplanar (NC) plans using the Pareto Optimal Projection Search (POPS) algorithm.

Methods: Noncoplanar radiation therapy treatment planning has the potential to improve dosimetric quality as compared to traditional coplanar techniques. Likewise, automated treatment planning algorithms can reduce a planner's active treatment planning time and remove inter-planner variability. Read More

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September 2021

Predicting personalised optimal arc parameter using knowledge-based planning model for inoperable locally advanced lung cancer patients to reduce organ at risk doses.

Biomed Phys Eng Express 2021 Sep 22;7(6). Epub 2021 Sep 22.

Radiotherapy Physics, Queen's Centre for Oncology, Hull University Teaching Hospitals NHS Trust, Cottingham, HU16 5JQ, United Kingdom.

. Volumetric modulated arc therapy (VMAT) allows for reduction of organs at risk (OAR) volumes receiving higher doses, but increases OAR volumes receiving lower radiation doses and can subsequently increasing associated toxicity. Therefore, reduction of this low-dose-bath is crucial. Read More

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September 2021

Radiation Therapy Planning of Thoracic Tumors: A Review of Challenges Associated With Lung Toxicities and Potential Perspectives of Gallium-68 Lung PET/CT Imaging.

Front Med (Lausanne) 2021 27;8:723748. Epub 2021 Aug 27.

Service de médecine nucléaire, CHRU de Brest, EA3878 (GETBO), Université de Brest, Brest, France.

Despite the introduction of new radiotherapy techniques, such as intensity modulated radiation therapy or stereotactic body radiation therapy, radiation induced lung injury remains a significant treatment related adverse event of thoracic radiation therapy. Functional lung avoidance radiation therapy is an emerging concept in the treatment of lung disease to better preserve lung function and to reduce pulmonary toxicity. While conventional ventilation/perfusion (V/Q) lung scintigraphy is limited by a relatively low spatial and temporal resolution, the recent advent of Gallium V/Q lung PET/CT imaging offers a potential to increase the accuracy of lung functional mapping and to better tailor lung radiation therapy plans to the individual's lung function. Read More

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Multi-criteria optimization for planning volumetric-modulated arc therapy for prostate cancer.

PLoS One 2021 10;16(9):e0257216. Epub 2021 Sep 10.

Department of Radiation Oncology, Yeungnam University College of Medicine, Daegu, Republic of Korea.

We aimed to compare the volumetric-modulated arc therapy (VMAT) plans with or without multi-criteria optimization (MCO) on commercial treatment-planning systems (Eclipse, Varian Medical System, Palo Alto, CA, USA) for patients with prostate cancer. We selected 25 plans of patients with prostate cancer who were previously treated on the basis of a VMAT plan. All plans were imported into the Eclipse Treatment Planning System version 15. Read More

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September 2021

Comparison of combinations of irradiation techniques and jaw conditions in intensity-modulated radiotherapy for lung cancer.

J Appl Clin Med Phys 2021 Sep 10. Epub 2021 Sep 10.

Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China.

Purpose: To assist in the selection of a suitable combination of an irradiation technique and jaw condition in intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc radiotherapy (VMAT) for lung cancer treatment plans.

Materials And Methods: Thirty patients with lung cancer who underwent radiotherapy were enrolled retrospectively. They were categorized as having central lung cancer, peripheral lung cancer with mediastinal lymph node metastasis (peripheral E lung cancer), and peripheral lung cancer without mediastinal lymph node metastasis (peripheral N lung cancer). Read More

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September 2021

Comparison of calculation algorithms to predict the IQM detector response for various modulation degree of VMAT treatment plans on linear accelerator equipped with the HD120 MLC.

Med Phys 2021 Sep 9. Epub 2021 Sep 9.

Medical Physics Department, Maria Sklodowska-Curie National Research Institute of Oncology, Roentgena 5, Warsaw, 02-781, Poland.

Purpose: The calculation model for the integral quality monitor (IQM) system does not take into account the characteristics of the HD120 multileaf collimator (MLC), which some Varian accelerators are equipped with. Some treatment plans prepared with this collimator are characterized by a high level of modulation. The aim of the work was to prepare a model for that collimator and to determine the influence of modulation on the results of the verification carried out with the use of the IQM system. Read More

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September 2021

Predicting the effect of indirect cell kill in the treatment of multiple brain metastases via single-isocenter/multitarget volumetric modulated arc therapy stereotactic radiosurgery.

J Appl Clin Med Phys 2021 Sep 8. Epub 2021 Sep 8.

Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky, USA.

Purpose: Due to spatial uncertainty, patient setup errors are of major concern for radiosurgery of multiple brain metastases (m-bm) when using single-isocenter/multitarget (SIMT) volumetric modulated arc therapy (VMAT) techniques. However, recent clinical outcome studies show high rates of tumor local control for SIMT-VMAT. In addition to direct cell kill (DCK), another possible explanation includes the effects of indirect cell kill (ICK) via devascularization for a single dose of 15 Gy or more and by inducing a radiation immune intratumor response. Read More

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September 2021

Evaluation of VMAT Planning Strategies for Prostate Patients with Bilateral Hip Prosthesis.

Technol Cancer Res Treat 2021 Jan-Dec;20:15330338211038490

7005Beaumont Health, Troy, MI, USA.

In this study, we investigate linac volumetric-modulated arc therapy (VMAT) planning strategies for bilateral hip prostheses prostate patients with respect to plan quality and deliverability, while limiting entrance dose to the prostheses. Three VMAT plans were retrospectively created for 20 patients: (1) partial arcs (PA), (2) 2 full arcs optimized with 500 cGy max prostheses dose (MD), and (3) 2 full arcs optimized with max dose-volume histogram (DVH) constraint of 500 cGy to 10% prostheses volume (MDVH). PA techniques contained 6 PA with beam angles that avoid entering each prosthesis. Read More

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September 2021

A dosimetric and radiobiological evaluation of VMAT following mastectomy for patients with left-sided breast cancer.

Radiat Oncol 2021 Sep 6;16(1):171. Epub 2021 Sep 6.

Department of Radiation Oncology, Jiangxi Cancer Hospital of Nanchang University, Nanchang, Jiangxi, 330029, People's Republic of China.

Background: To compare the dosimetric, normal tissue complication probability (NTCP), secondary cancer complication probabilities (SCCP), and excess absolute risk (EAR) differences of volumetric modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT) for left-sided breast cancer after mastectomy.

Methods And Materials: Thirty patients with left-sided breast cancer treated with post-mastectomy radiation therapy (PMRT) were randomly enrolled in this study. Both IMRT and VMAT treatment plans were created for each patient. Read More

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September 2021

Virtual bronchoscopy-guided lung SAbR: dosimetric implications of using AAA versus Acuros XB to calculate dose in airways.

Biomed Phys Eng Express 2021 Sep 15;7(6). Epub 2021 Sep 15.

University of Maryland School of Medicine, Baltimore, MD, United States of America.

In previous works, we showed that incorporating individual airways as organs-at-risk (OARs) in the treatment of lung stereotactic ablative radiotherapy (SAbR) patients potentially mitigates post-SAbR radiation injury. However, the performance of common clinical dose calculation algorithms in airways has not been thoroughly studied. Airways are of particular concern because their small size and the density differences they create have the potential to hinder dose calculation accuracy. Read More

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September 2021

Fully automated planning and delivery of hippocampal-sparing whole brain irradiation.

Med Dosim 2021 Sep 1. Epub 2021 Sep 1.

Department of Radiation Oncology, Loyola University Medical Center, Maywood, IL, 60153 USA.

The goal of this study is to fully automate the treatment planning and delivery process of hippocampal-sparing whole brain irradiation (HS-WBRT) by combining a RapidPlan (RP) knowledge-based planning model and HyperArc (HA) technology. Additionally, this study compares the dosimetric performance of RapidPlan-HyperArc (RP-HA) treatment plans with RP plans and volumetric modulated arc therapy (VMAT) plans. Ten patients previously treated with HS-WBRT using conventional VMAT were re-planned using RP-HA technique and RP model for HS-WBRT. Read More

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September 2021

Image-guided volumetric-modulated arc therapy of total body irradiation: An efficient workflow from simulation to delivery.

J Appl Clin Med Phys 2021 Sep 4. Epub 2021 Sep 4.

Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, USA.

Introduction: Using multi-isocenter volumetric-modulated arc therapy (VMAT) for total body irradiation (TBI) may improve dose uniformity and vulnerable tissue protection compared with classical whole-body field technique. Two drawbacks limit its application: (1) VMAT-TBI planning is time consuming; (2) VMAT-TBI plans are sensitive to patient positioning uncertainties due to beam matching. This study presents a robust planning technique with image-guided delivery to improve dose delivery accuracy. Read More

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September 2021

Dosimetric comparison of intensity modulated radiotherapy and intensity modulated proton therapy in the treatment of recurrent nasopharyngeal carcinoma.

Med Dosim 2021 Aug 29. Epub 2021 Aug 29.

Department of Medical Physics, Pamela Youde Nethersole Eastern Hospital, Hong Kong.

Background And Purpose: To compare the dosimetric performance of Intensity Modulated Proton Therapy (IMPT) and Intensity Modulated Radiotherapy (IMRT) in terms of target volume coverage and sparing of neurological organs-at-risk (OARs) in salvaging recurrent nasopharyngeal carcinoma (rNPC). The maximum dose to the internal carotid artery (ICA) and nasopharyngeal (NP) mucosa, which are associated with potential carotid blowout and massive epistaxis, were also evaluated.

Materials And Methods: IMRT and IMPT treatment plans were created for twenty patients with locally advanced rNPC. Read More

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Influence of target dose heterogeneity on dose sparing of normal tissue in peripheral lung tumor stereotactic body radiation therapy.

Radiat Oncol 2021 Aug 30;16(1):167. Epub 2021 Aug 30.

Department of Radiation Oncology, Cancer Center, West China Hospital, Sichuan University, No.37 Guoxue Alley, Wuhou District, Chengdu, 610041, Sichuan, China.

Objective: To evaluate the influence of target dose heterogeneity on normal tissue dose sparing for peripheral lung tumor stereotactic body radiation therapy (SBRT).

Methods: Based on the volumetric-modulated arc therapy (VMAT) technique, three SBRT plans with homogeneous, moderate heterogeneous, and heterogeneous (HO, MHE, and HE) target doses were compared in 30 peripheral lung tumor patients. The prescription dose was 48 Gy in 4 fractions. Read More

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Significant Reduction in Vertebral Artery Dose by Intensity Modulated Proton Therapy: A Pilot Study for Nasopharyngeal Carcinoma.

J Pers Med 2021 Aug 22;11(8). Epub 2021 Aug 22.

Department of Radiation Oncology and Proton & Radiation Therapy Center, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan.

Intensity modulated proton therapy (IMPT) with the vertebral artery (VA)-sparing technique has been initially proposed in our institution. This pilot study was conducted to compare the dose to VAs between IMPT and volumetric-modulated arc therapy (VMAT) for patients with nasopharyngeal carcinoma (NPC). A total of six patients with NPC treated by IMPT were enrolled in the study. Read More

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Use of Continuous Positive Airway Pressure (CPAP) to Limit Diaphragm Motion-A Novel Approach for Definitive Radiation Therapy for Inoperable Pleural Mesothelioma: A Pilot Study.

Biology (Basel) 2021 Jul 24;10(8). Epub 2021 Jul 24.

Department of Radiotherapy, Institute of Oncology, Davidoff Cancer Center, Rabin Medical Center-Beilinson Hospital, Petach Tikva 4941492, Israel.

Malignant pleural mesothelioma (MPM) is a deadly disease and radiotherapy (RT) plays an important role in its management. Recent developments in technique have made it is possible to deliver RT to MPM in the intact lung. However, it is imperative to reduce normal lung doses. Read More

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Dosimetric impact of contrast-enhanced 4d computed tomography for stereotactic body radiation therapy of hepatocelluar carcinoma.

Rep Pract Oncol Radiother 2021 12;26(4):598-604. Epub 2021 Aug 12.

Govt. Cancer Hospital, NSCB Medical College, Jabalpur, Madhya Pradesh, India.

Background: A purpose of the study was to investigate the dosimetric impact of contrast media on dose calculation using average 4D contrast-enhanced computed tomography (4D-CECT) and delayed 4D-CT (d4D-CT) images caused by CT simulation contrast agents for stereotactic body radiation therapy (SBRT) of liver cases.

Materials And Methods: Fifteen patients of liver SBRT treated using the volumetric modulated arc therapy (VMAT) technique were selected retrospectively. 4D-CECT, and d4D-CT were acquired with the Anzai gating system and GE CT. Read More

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Feasibility of arm-draining lymph node-sparing radiotherapy of breast cancer: A pilot planning study.

J Med Imaging Radiat Oncol 2021 Aug 24. Epub 2021 Aug 24.

Department of Radiation Oncology, Crown Princess Mary Cancer Centre, Westmead Hospital, Sydney, New South Wales, Australia.

Introduction: Lymphoedema following axillary radiotherapy for breast cancer causes significant morbidity. Our goal was to evaluate the feasibility of sparing the lymph node that drains the arm's lymphatics (ARM node) while achieving standard dose constraints for whole breast and comprehensive lymph node irradiation.

Methods: Six patients underwent lymphoscintigraphy and SPECT CT to identify the breast sentinel node (SN) and ARM node. Read More

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Dosimetric Comparison Between Helical Tomotherapy and Volumetric Modulated Arc Therapy in Patients With Malignant Pleural Mesothelioma.

Clin Oncol (R Coll Radiol) 2021 Aug 21. Epub 2021 Aug 21.

Department of Radiation Oncology, University Hospital Bonn, University of Bonn, Bonn, Germany.

Aims: To carry out a dosimetric comparison and constraints feasibility proof of adjuvant radiotherapy through helical tomotherapy or volumetric modulated arc therapy (VMAT) for malignant pleural mesothelioma patients after pleurectomy/decortication.

Materials And Methods: Retrospective calculations were carried out on previously acquired simulations. A whole-pleura volume with 50. Read More

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Can Radiotherapy Quality Assurance (RT QA) improve nasopharyngeal cancer outcomes in low- and middle-income countries (LMICs) - Reporting the first phase of a prospective International Atomic Energy Agency (IAEA) study.

Int J Radiat Oncol Biol Phys 2021 Aug 18. Epub 2021 Aug 18.

Department of Clinical Oncology, The University of Hong Kong-Shenzhen Hospital and the University of Hong Kong, CHINA.

Background: The majority of new NPC cases occur in LMICs, but these patients experience poorer overall survival than that of new NPC cases in high income countries. The goal of this research project is to determine whether the introduction of a radiotherapy quality assurance (RT QA) programme can ultimately improve NPC patient outcomes in LMICs. This study reports the results of the first phase of the XXXX XXXX Project (XXX). Read More

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