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Results for "collimator mlc": 38 found

4D Monte Carlo Dose Evaluation for Mobile Targets in a Magnetic Field

Authors: Odunola Grace Babawale, B. Gino Fallone, Alireza Gazor, Andrei D. Ghila, Patricia A. K. Oliver, Michael W. Reynolds, Keith D. Wachowicz, Tania Rosalia Wood, Shima Y. Tari, Eugene Yip, Jihyun Yun

Affiliation: Nova Scotia Health, Dept. of Medical Physics and Dalhousie University, Dept. of Physics and Atmospheric Science, Dept. of Radiation Oncology, Dept. of Medical Physics, Cross Cancer Institute and Dept. of Oncology, University of Alberta; MagnetTx Oncology Solutions, www.magnetTX.com, Department of Medical Physics, Arthur J. E. Child Comprehensive Cancer Centre, Dept. of Medical Physics, Cross Cancer Institute and Dept. of Oncology, University of Alberta, Department of Medical Physics, BC Cancer, Medical Physics Division, Department of Oncology, University of Alberta and Department of Medical Physics, Cross Cancer Institute

Abstract Preview: Purpose: To evaluate the dose to a moving target and its surroundings in a magnetic field using 4D-Monte-Carlo (MC) simulation.
Methods: The study utilizes a previously validated MC model of our li...

A Novel Semi-Analytic Approach for Dose Calculation in Proton Minibeam Radiotherapy

Authors: Hao Gao, Wangyao Li, Yuting Lin, Chao Wang, Wei Wu

Affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Department of Radiation Oncology, University of Kansas Medical Center

Abstract Preview: Purpose: Proton minibeam radiation therapy (pMBRT) delivers a unique peak-and-valley dose pattern using collimators with narrow slits, offering improved normal tissue sparing compared to conventional ...

A Plan Complexity Comparison between Monaco and Eclipse - Meta Analysis of 17,000 Plans and 30,000 Beams

Authors: Christopher Colyer, Leon F Dunn, Jonathan Dunning, Simon Goodall, Andy Schofield

Affiliation: GenesisCare

Abstract Preview: Purpose: Modern radiotherapy is characterized by complex treatment plans utilizing dynamic MLCs, gantry positions and recently, collimator rotations. The purpose of this work was to compare the plan c...

An International Multi-Institutional Espresso Study of Developing the Specialized-Equipment-Free Remote Audit for Single-Isocenter Multi-Target Stereotactic Radiosurgery

Authors: Juan-Francisco Calvo-Ortega, Andrew Cousins, Ashley Cullen, Andrew Dipulia, Peter B. Greer, Seng Boh Gary Lim, Shih-Chi Lin, D. Michael Lovelock, Conor McGarry, Victoria Robinson, Cameron Stanton, Baozhou Sun, Ching-Ling Teng, Gemma Warner, Benjamin J. Zwan

Affiliation: Northern Ireland Cancer Centre, Baylor College of Medicine, Department of Medical Physics, Memorial Sloan Kettering Cancer Center, Christchurch Hospital, Northwell, Central Coast Cancer Centre, Calvary Mater Hospital, Hospital Quironsalud Barcelona, Icahn School of Medicine at Mount Sinai, Chris O'Brien Lifehouse, University of Newcastle

Abstract Preview: Purpose: This multi-institution Electronic Silicon-based Remote Survey of Small-field Output (ESPRESSO) study aims to develop the remote audit process to evaluate the safety of single-isocenter multi-...

Assessing Mlc Errors and Their Dosimetric Impact Delivered on Elekta Linear Accelerator from Two TPS Systems

Authors: Richard Lesieur, Olivia Magneson, David E. Solis, Sotirios Stathakis

Affiliation: Louisiana State University, Mary Bird Perkins Cancer Center

Abstract Preview: Purpose: This study evaluates the deliverability and precision of multileaf collimator (MLC) positioning in treatment plans generated by two different Treatment Planning Systems (TPS), Monaco and Pinn...

Characterization of Linear Energy Transfer Spectra in Mini Beam Spatially Fractionated Proton Therapy

Authors: Serdar Charyyev, Kaan Dere, Edgar Gelover, Mohammad Khurram Khan, Liyong Lin, Mark McDonald, Cristina Oancea, Alexander Stanforth, Sibo Tian, Suk Whan (Paul) Yoon, Mingyao Zhu

Affiliation: Department of Radiation Oncology, Stanford University, Stanford University, Emory University, Department of Radiation Oncology and Winship Cancer Institute, Emory University, Advacam

Abstract Preview: Purpose: The conventional implementation of proton spatially fractionated radiotherapy (SFRT) utilizes physical collimators with apertures to generate minibeams, creating alternating regions of high-d...

Characterization of a Novel Large-Sized Epid System from the Newly Released Ring Shape Radiation Therapy Halos Tx

Authors: Sen Bai, Guyu Dai, Dong Gao, Lecheng Jia, Guangjun Li, Yanfang Liu, Ying Song, Qing Xiao, Wei Zhang

Affiliation: United Imaging Healthcare, West China Hospital of Sichuan University, Shenzhen United Imaging Research Institute of Innovative Medical Equipment

Abstract Preview: Purpose:
Electronic portal imaging device (EPID) is currently the most widely used in-vivo dosimetry (IVD) device. However, the effective detector area shortage hinders further applications. This s...

Characterizing and Modeling Higher-Order Motions of Collimator Subsystem on a 60RPM Gantry Linac for Improved Small Target Dosimetry

Authors: David J. Carlson, Yiu-Hsin Chang, Huixiao Chen, Zhe (Jay) Chen, Blake Gaderlund, Ray Yang

Affiliation: RefleXion Medical, Department of Therapeutic Radiology, Yale University School of Medicine

Abstract Preview: Purpose: To address the root cause of dosimetric discrepancy for small central targets (<2cm) especially sensitive to geometric alignment of beamlets, by modeling higher-order oscillations of the coll...

Combining Proton Flash and Spatially Fractionated Radiotherapy – Experimental and Simulation Based Dosimetric Characterization

Authors: Gulakhshan M Hamad, Sina Mossahebi, Yannick P. Poirier, Amit Sawant

Affiliation: University of Maryland School of Medicine, Maryland University Baltimore

Abstract Preview: Purpose:
The combination of ultra-high dose rate (UHDR) proton therapy, known for normal tissue sparing, with spatially-fractionated radiotherapy (SFRT), promising enhanced tumor control and tissue...

Comparative Analysis of Four Measurement Methods for Multileaf Collimator Backlash

Authors: Niko Ahjoniemi, Antti Kulmala, Katja Peltola

Affiliation: Clinical Research Institute HUS, Helsinki University Hospital

Abstract Preview: Purpose: To determine the backlash of a multileaf collimator (MLC) using four measurement methods: motor encoder (primary readout), linear potentiometer (secondary readout), amorphous silicon panel (p...

Comparison of the Sun Nuclear Multi-Met Winston Lutz Test and Varian's Machine Performance Check for Isocenter Alignment for Rotational Accuracy

Authors: Junsheng Cao, Luis A. Maduro Bustos, Khushdeep Singh

Affiliation: Overlook Medical Center, Atlantic Health System at Morristown Medical Center

Abstract Preview: Purpose: To evaluate the agreement between the Sun Nuclear Multi-Met Winston Lutz test (WL) and Varian’s Machine Performance Check (MPC) in assessing isocenter alignment, couch, and collimator rotatio...

Comprehensive Commissioning of an O-Ring-Shaped Image-Guided Radiotherapy System with a Gimbal-Mounted Linear Accelerator

Authors: Tetsuo Fukuda, Hideaki Hirashima, Kohei Kawata, Yukako Kishigami, Takashi Mizowaki, Mitsuhiro Nakamura, Yohei Sawada, Maika Urago

Affiliation: Kyoto University, kyotoUnivercity, Hitachi high-tech, Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University

Abstract Preview: Purpose: To present the comprehensive commissioning results of the O-ring shaped linac, OXRAY.
Materials and Methods: OXRAY enables a novel three-dimensional unicursal noncoplanar irradiation metho...

Deep Learning-Based Multileaf Collimator Sequence Prediction for Automated VMAT Treatment Planning in Pancreatic Cancer

Authors: Zixu Guan, Takahiro Iwai, Takashi Mizowaki, Mitsuhiro Nakamura, Michio Yoshimura

Affiliation: Kyoto University, Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University

Abstract Preview: Purpose:
The goal of this study is to develop a fully automated treatment planning approach for VMAT in pancreatic cancer that can convert patient anatomy into LINAC machine parameters. In this wor...

Determine the Isocenter and Its Size for MR Linac Unity Part1: (U V) of Cax

Authors: Ting Chen, Siming Lu, Tanxia Qu, Hesheng Wang

Affiliation: NYU Langone Health

Abstract Preview: Purpose: This study, the first in a two-part series, aims to determine the isocenter position and size for the MR Linac UNITY, focusing on the central axis (CAX) alignment of its Multi-Leaf Collimator...

Development of a Beam Profile Variation Observation Model for Intensity Modulated Radiotherapy

Authors: Kaile Li

Affiliation: Alexander T. Augusta Miliary Medical Center

Abstract Preview: Purpose: To develop a experimental method in observation of beam profile transfer model in intensity modulated radiotherapy (IMRT).
Methods: A picket fence plan was generated in Eclipse treatment p...

Development of an Ultrafast MR Technique to Detect Linac Radiation Pulses for Biological Imaging on a Clinical 0.35T MR-Linac

Authors: Pierre Gardair, Johnathan E Leeman, Claire Keun Sun Park, Atchar Sudhyadhom

Affiliation: Brigham and Women’s Hospital, Dana Farber Cancer Institute, Harvard Medical School, Brigham and Women’s Hospital and Dana Farber Cancer Institute, Harvard Medical School,, Brigham and Women’s Hospital and Dana Farber Cancer Institute, Harvard Medical School, Harvard Medical School

Abstract Preview: Purpose: Dose is a poor surrogate for radiobiological damage but no in vivo technology exists to directly measure damage such as DNA strand breaks and free radical generation (FRG). Recent advances in...

Evaluation of Potential Dosimetric Risks from Intra-Fractional Motion in Single-Isocenter Stereotactic Radiosurgery

Authors: Brian D. Casto, Mathew Y Kang, Lichung Ku, Samuel J Wang, Joseph B. Ying, Walker Ray Zimmerman

Affiliation: Salem Health Cancer Center, Salem Health

Abstract Preview: Purpose: Varian HyperArc is an advanced radiotherapy module designed to efficiently deliver high-quality multi-target stereotactic radiosurgery (SRS) treatment plans on Varian linacs. However, the int...

Evaluation of the Improvements of a New Leaf Model (Enhanced Leaf Model) for the Halcyon

Authors: Evan Barber, Gloria P. Beyer, Callum Hartley, Jordi Saez, Philip Wheeler

Affiliation: Department of Radiation Oncology, Hospital Clinic de Barcelona, Department of Radiotherapy Physics, Velindre University NHS Trust, Medical Physics Services, LLC

Abstract Preview: Purpose: To evaluate the Enhanced Leaf Model (ELM) in Eclipse v18 to the standard leaf model for the Halcyon multileaf collimator (MLC) using a measurement-based method.
Methods: The Halcyon’s doub...

FMEA for Optimizing Patient-Specific QA Program in IMRT: Insights from Diverse Practices

Authors: Bing-Hao Chiang, Eric C. Ford, Juergen Meyer, Timothy D. Solberg

Affiliation: Department of Radiation Oncology, Fred Hutchinson Cancer Center, University of Washington

Abstract Preview: Purpose: This study evaluated the potential risk reduction of various pretreatment patient-specific quality assurance (PSQA) programs for Intensity Modulated Radiation Therapy (IMRT) in mitigating fai...

Film-Based Method for Accurate Radiation Isocenter Determination in Linear Accelerators Using 3D Starshot

Authors: Robert A. Corns, Mohammad Kanber

Affiliation: East Carolina University, East Carolina University Brody School of Medicine

Abstract Preview: Purpose:
Accurate determination of the radiation isocenter is crucial for precise radiotherapy treatments, directly impacting patient safety and treatment quality. This study presents a computation...

High-Fidelity Monte-Carlo Model Development and Validation of a 0.5T Bi-Planar Linac-MR Using Topas: Multileaf Collimator Modeling, Positioning, and Dose Verification in Slab Phantoms

Authors: B. Gino Fallone, Alireza Gazor, Andrei D. Ghila, Gawon Han, Patricia A. K. Oliver, Michael W. Reynolds, Keith D. Wachowicz, Tania Rosalia Wood, Shima Y. Tari, Eugene Yip

Affiliation: Medical Physics Division, Department of Oncology, University of Alberta, Nova Scotia Health, Dept. of Medical Physics and Dalhousie University, Dept. of Physics and Atmospheric Science, Dept. of Radiation Oncology, Dept. of Medical Physics, Cross Cancer Institute and Dept. of Oncology, University of Alberta; MagnetTx Oncology Solutions, www.magnetTX.com, Department of Medical Physics, Arthur J. E. Child Comprehensive Cancer Centre, Dept. of Medical Physics, Cross Cancer Institute and Dept. of Oncology, University of Alberta, Department of Medical Physics, BC Cancer, Medical Physics Division, Department of Oncology, University of Alberta and Department of Medical Physics, Cross Cancer Institute

Abstract Preview: Purpose: To develop and validate a high-fidelity Monte-Carlo (MC) model of a 0.5T bi-planar Linac-MR in TOPAS, focusing on accurate Multileaf Collimator (MLC) modelling and positioning for open apertu...

Impact of Ion Chamber Selection on Enhanced Leaf Modeling Predictions of Dosimetric Leaf Gap and Leaf Transmission Factors

Authors: Michael Ashenafi, Nicholas Becerra Espinosa, Mario Ramos Gallardo, Matthew Pacella, Sean M. Tanny

Affiliation: Department of Radiation Oncology, University of Rochester

Abstract Preview: Purpose: A new multileaf collimator (MLC) model has been introduced in Varian Eclipse v18.0, with the treatment planning system (TPS) explicitly modeling the leaf end effects. The vendor recommends a ...

Impact of Mlc and Collimator Errors in Psqa Techniques for VMAT Breast Treatment Plans

Authors: Maria Jose Almada, Oscar Apaza, Carlos Bohorquez, Ezequiel Cabrera, Rogelio Diaz Moreno, Maximiliano Musso, Rosa Petit, Carlos Daniel Venencia, Lucy D. Wolfsberger

Affiliation: LAP, FaMAF, UNC, Instituto Zunino - Fundacion Marie Curie

Abstract Preview: Purpose:
PSQA employs gamma analysis to verify the planned versus delivered dose. Evaluating the effectiveness of PSQA techniques in identifying errors is crucial. This study aims to incorporate ML...

Improvements of Lateral Penumbra at Various Depth Regions in Scanned Proton Treatment System with a Multi-Leaf Collimator: Dose Verifications and Plan Comparisons

Authors: Takahiro Kato, Teiji Nishio, Masataka Oita, Robabeh Rahimi, Yuki Tominaga, Yushi Wakisaka

Affiliation: University of Maryland, Department of Radiological Sciences, School of Health Sciences, Fukushima Medical University, Medical Co. Hakuhokai, Osaka Proton Therapy Clinic, Medical Physics Laboratory, Division of Health Science, Osaka University Graduate School of Medicine, Faculty of Interdisciplinary Science and Engineering in Health Systems, Okayama University

Abstract Preview: Purpose: This study evaluated dose verifications and lateral penumbra improvements for scanned proton therapy plans with and without a multi-leaf collimator (MLC) under various air gaps.
Methods: E...

Inter-System and Inter-Layer Dlg Variations in Halcyon/Ethos Mlcs: Implications for Dosimetric Matching and User-Adjustable TPS Models

Authors: Evan Barber, Gloria P. Beyer, Matthew J. Daniels, Callum Hartley, Jordi Saez, Philip Wheeler

Affiliation: TrueNorth Medical Physics, Department of Radiotherapy Physics, Velindre University NHS Trust, Department of Radiation Oncology, Hospital Clinic de Barcelona, Medical Physics Services, LLC

Abstract Preview: Purpose: To quantify inter-system and inter-layer dosimetric leaf gap (DLG) variations in Halcyon/Ethos multileaf collimators (MLCs) using custom sweeping gap tests, and to evaluate implications for c...

Monte Carlo Modeling of an Experimental X-Ray Fluorescence Computed Tomography (XFCT) System with a Pixelated CdTe Detector

Authors: Sang Hyun Cho, Sandun Y. Jayarathna, Neerajan Nepal

Affiliation: The University of Texas MD Anderson Cancer Center

Abstract Preview: Purpose: To develop/validate a Monte Carlo (MC) model of an experimental benchtop x-ray fluorescence computed tomography (XFCT) system with a pixelated CdTe detector that can be used for MC simulation...

Monte Carlo Simulation of Surface Radiation Dose for Cherenkov Imaging: Comparison with Commissioning Data for Truebeam and Halcyon

Authors: Hongjing Sun, Weibing Yang, Timothy C. Zhu, Yifeng Zhu

Affiliation: University of Pennsylvania

Abstract Preview: Purpose: This study aims to compare the commissioning results of TrueBeam and Halcyon linear accelerators with Monte Carlo (MC) simulations conducted using TOPAS. The ultimate goal is to leverage MC s...

Optimized Dosimetric Planning for Trigeminal Neuralgia Using Cyberknife S7 Precision TPS with Volo Optimizer

Authors: Amy Fitzpatrick, Kim Howard, Julius G. Ojwang, Neelu Soni

Affiliation: Mercy Hospital Springfield

Abstract Preview: Purpose: This study evaluates the dosimetric advantages and workflow improvements of the CyberKnife S7 Precision Treatment Planning System (TPS) with the VOLO optimizer for stereotactic radiosurgery (...

Optimizing Motion Management QA: Clinical Integration of Aapm TG-306 for the Radixact Synchrony System

Authors: Hulya Ozdemir Buss, Jeffrey Geiger, Kim Howard, Julius G. Ojwang, Neelu Soni

Affiliation: Mercy Hospital Springfield

Abstract Preview: Purpose: The Radixact Synchrony system integrates real-time motion tracking and compensates to improve treatment accuracy for moving targets. This study presents a streamlined and efficient quality as...

Precise Measurement of Leaf Open Time in Tomotherapy Using Advanced Plastic Scintillators

Authors: Marcos Feijoo, Mamoru Ichiki, Tatsuya Maeda, Tatsuhiro Makino, Tomonori Megumi, Tadashi Nakabayashi, Yukino Nakata, Shuichi Ozawa, Daishi Takayama

Affiliation: Hiroshima High-Precision Radiotherapy Cancer Center, Blue Physics LLC, Imamura General Hospital, Accuray Inc.

Abstract Preview: Purpose: This study aims to accurately measure the leaf open time (LOT) of the multi-leaf collimator (MLC) in tomotherapy using an advanced plastic scintillator detector (PSD) with high time resolutio...

Proactive Quality Assurance for Adaptive Radiotherapy: Real-Time Mlc Verification with Myqa SRS

Authors: James L. Giltz, Michael J. Merrick

Affiliation: Alyzen Medical Physics, University of Kentucky

Abstract Preview: Purpose: To evaluate the capability of MyQA SRS in performing high-resolution machine QA to verify multileaf collimator (MLC) behavior and integrity for adaptive radiotherapy (ART). This study demonst...

Proton Minibeam Radiotherapy: Commissioning, Treatment Planning, and Delivery

Authors: Stephen M Corner, Daiki Hara, Jiasen Ma, Robert W Mutter, Mark D. Pepin, Nicholas B. Remmes, Hok Seum Wan Chan Tseung

Affiliation: Mayo Clinic - Rochester

Abstract Preview: Purpose: Proton minibeam radiotherapy (pMBRT) is a form of spatially fractionated radiation therapy leveraging submillimeter beams to improve the therapeutic ratio. We report on collimator design, com...

Reinforcement Learning Based Machine Parameter Optimization for Two-Arc Prostate VMAT Planning

Authors: William T. Hrinivich, Junghoon Lee, Lina Mekki

Affiliation: Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Department of Biomedical Engineering, Johns Hopkins University, Johns Hopkins University

Abstract Preview: Purpose: Volumetric modulated arc therapy (VMAT) planning is a computationally expensive process. In this work, we propose a reinforcement learning (RL) framework to automatically optimize dose rate a...

Research on the Target Current Pulse Counting Method for Measuring the Output Dose of Medical Standing Wave Electronic Linear Accelerator

Authors: Shixiong Huang, Daming Li

Affiliation: The Affiliated Nanhua Hospital, University of South China, The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University/Hunan Cancer Hospital

Abstract Preview: Purpose: To assess the feasibility of using target current pulse signals to evaluate the output dose of medical standing wave electronic linear accelerators.
Methods: The Target I signal of the acc...

Robustness Enhancement for VMAT-TBI Planning and Treatment Delivery

Authors: Courtney R. Buckey, Quan Chen, Suzanne J. Chungbin, Edward L. Clouser, Yi Rong, Jun Tan, Jennifer Yan, Xiang Sheng Yan

Affiliation: Mayo Clinic Arizona, Mayo Clinic

Abstract Preview: Purpose:
To identify planning techniques that consistently result in robust VMAT-TBI plans that allow for larger patient setup errors.
Methods:
Conventional planning method often results in p...

Robustness Evaluation of Aperture Shape Controller in Postmastectomy Radiotherapy of Breast Cancer Using Volumetric Modulated Arc Therapy

Authors: Yukio Fujita, Satoshi Ishikura, Fumiki Ito, Yujiro Nakajima, Takumi Sakamoto, Naoki Tohyama, Ryohei Yamauchi

Affiliation: Komazawa University Graduate School, St. Luke's International Hospital

Abstract Preview: Purpose: The aperture shape controller (ASC) is an Eclipse feature that increases muti-leaf collimator (MLC) aperture size. This study aimed to evaluate the effects of ASC settings on the robustness o...

Sentinel: Development and Implementation of an Automated, Passive Varian Log File and Treatment Plan Analysis

Authors: Leon Dunn

Affiliation: IsoAnalytics Pty. Ltd.

Abstract Preview: Purpose: The purpose of this work is to present the development and results of an automated Varian Trajectory Log file processing software platform called Sentinel (IsoAnalytics Pty. Ltd.).
Methods...

Spot Map Modification for Planning Optimization on a Spot Scanning Proton System with Adaptive Aperture

Authors: Austen N. Curcuru, Winter Green, Yao Hao, Jiayi Liu, Yuting Peng, Tiezhi Zhang, Xiandong Zhao

Affiliation: Washington University School of Medicine, Department of Radiation Oncology, WashU Medicine, Virginia Commonwealth University, Washington University School of Medicine, Washington University in St. Louis

Abstract Preview: Purpose: We proposed a treatment planning optimization method that utilizes customized spot map modification to achieve less dosimetry uncertainty, monitor unit ratio (MUR) and neutron dose in a spot ...