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Results for "leaf collimator": 25 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 Dual Energy CT-Guided Intelligent Radiation Therapy Platform

Authors: Jiayi Chen, Manju Liu, Ning Wen, Haoran Zhang, Yibin Zhang

Affiliation: Department of Radiation Oncology, Ruijin Hospital, Department of Radiology, Ruijin Hospital Shanghai Jiaotong University School of Medicine, Duke Kunshan University, Department of Radiation Oncology,Ruijin Hospital, Shanghai Jiao Tong University School of Medicine

Abstract Preview: Purpose: This study introduces a novel Dual Energy CT (DECT)-Guided Intelligent Radiation Therapy (DEIT) platform designed to streamline and optimize the radiotherapy process. The DEIT system combines...

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-...

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...

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...

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...

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...

Diffusion-Based PET Image Enhancement in Bgrt

Authors: David J. Carlson, Huixiao Chen, Tianqi Chen, Jun Hou, Chi Liu, Qiong Liu, Henry S. Park, Huidong Xie

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

Abstract Preview: Purpose:
The RefleXion® X1 Biology-guided radiotherapy (BgRT) system consists of dual PET detectors, a 6MV linear accelerator (linac), a 64-leaf collimator, an MVD detector, and a CT scanner mounte...

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...

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 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 (...

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...

Real-Time 3D Dose Verification for MR-Guided Online Adaptive Radiotherapy (ART) Via Geometry-Encoded Deep Learning Framework

Authors: Steve B. Jiang, Dan Nguyen, Chenyang Shen, Fan-Chi F. Su, Jiacheng Xie, Shunyu Yan, Daniel Yang, Ying Zhang, You Zhang

Affiliation: Medical Artificial Intelligence and Automation (MAIA) Lab, Department of Radiation Oncology, UT Southwestern Medical Center, UT Southwestern Medical Center, Medical Artificial Intelligence and Automation (MAIA) Lab & Department of Radiation Oncology, UT Southwestern Medical Center, Medical Artificial Intelligence and Automation (MAIA) Laboratory, Department of Radiation Oncology, UT Southwestern Medical Center, The University of Texas at Dallas

Abstract Preview: Purpose: Fast dose verification is essential for the safety and efficiency of MR-guided adaptive radiotherapy (ART) as patients anxiously waiting on the treatment couch. Conventional tools often requi...

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...

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...