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Results for "square fields": 35 found

A Clarification on the Bandwidth Difference Method for MRI B0 Homogeneity Assessment

Authors: Christina Brunnquell, Daniel Vergara, Joseph Everett Wishart

Affiliation: University of Minnesota, University of Washington

Abstract Preview: Purpose: To propose and validate a correction to the bandwidth difference method presented in Task Group Report No. 325 for quantifying static magnetic field homogeneity (ΔB0).
Methods: A clarifica...

A Conditional Point Cloud Diffusion Model for Deformable Liver Motion Tracking Via a Single Arbitrarily-Angled X-Ray Projection (PCD-Liver)

Authors: Yunxiang Li, Hua-Chieh Shao, Chenyang Shen, Jing Wang, Jiacheng Xie, Shunyu Yan, 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) Laboratory, 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: Accurate liver deformable motion tracking is essential in image-guided radiotherapy to enable precise tumor targeting during treatment. We developed a conditional point cloud diffusion model ...

A Deep Learning-Based Method for Rapid Generation of Spot Weights in Single Field Optimization for Proton Therapy in Prostate Cancer

Authors: Yu Chang, Mei Chen

Affiliation: Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Department of Radiation Oncology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine

Abstract Preview: Purpose: Spot weights optimization, as a critical step in the proton therapy, is often time-consuming and labor-intensive. Deep learning, with its powerful learning and computational efficiency, can e...

A Diffusion-Based AI Framework for Continuous Deformable Image Registration and Time-Resolved Dynamic CT Generation

Authors: Mingli Chen, Xuejun Gu, Hao Jiang, Mahdieh Kazemimoghadam, Weiguo Lu, Gregory Szalkowski, Qingying Wang, Kangning Zhang

Affiliation: Medical Artificial Intelligence and Automation (MAIA) Lab, Department of Radiation Oncology, UT Southwestern Medical Center, UT Southwestern Medical Center, Department of Radiation Oncology, Stanford University School of Medicine

Abstract Preview: Purpose: Respiratory motion management is crucial for accurate radiation delivery to moving targets while protecting healthy tissue, relying on time-resolved volumetric imaging and continuous deformab...

A Dosimetric Study of Range-Compensated Proton Arc Therapy

Authors: Alonso N. Gutierrez, Daniel E. Hyer, Blake R. Smith

Affiliation: Miami Cancer Institute, Baptist Health South Florida, Iowa Health Care, University of Iowa

Abstract Preview: Purpose: To perform a feasibility study of optimizing and producing a compact range compensator to deliver single-energy pencil beam scanning (PBS) proton arc therapy treatments. Omitting energy chang...

A Novel 2D Scintillation Dosimeter Using Long Scintillating Fibers.

Authors: Louis Archambault, Luc Beaulieu, Alexis Horik, Sajjad Ahmad Khan

Affiliation: Département de Physique, de Génie Physique et D'optique, et Centre de Recherche sur le Cancer, Université Laval, Département de physique, de génie physique et d'optique, Université Laval

Abstract Preview: Purpose: This study presents a novel 2D scintillation dosimeter leveraging long scintillating fibers for quality assurance (QA) in radiotherapy. The primary goal is to optimize critical parameters suc...

A Novel Setup for Flash Radiotherapy Beam Delivery at Isocenter Using Downstream Electron Scattering

Authors: Dale W. Litzenberg, Ikechi S Ozoemelam, Rowan Paplanus, Michael Pillainayagam, Donald A. Roberts

Affiliation: University of Michigan, Oregon Health & Science University

Abstract Preview: Purpose: Clinical linear accelerators use dual foil scattering systems designed to achieve large uniform fields (up to 25×25cm²), which can reduce beam fluence by up to 93% compared to the unmodified ...

A Perturbative Approach to Determine the Charge Collection Efficiency in High Dose-per-Pulse Beams

Authors: Julien Bancheri, Jan P. Seuntjens

Affiliation: Medical Biophysics, University of Toronto, Princess Margaret Cancer Centre & University of Toronto

Abstract Preview: Purpose: To obtain an analytical expression for the charge collection efficiency of parallel-plate ionization chambers in high dose-per-pulse (DPP) beams that takes into account the square pulse time ...

A Python Package for GPU-Accelerated Photon Dose Calculation for Advanced and Generalizable Auto-Planning Approaches: Validation for Multiple Linear Accelerator Vendors and Institutions

Authors: Jaryd Ricardo Christie, Anthony J. Doemer, William T. Hrinivich, Junghoon Lee, Calin Reamy, Kundan S Thind

Affiliation: Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Johns Hopkins University, Henry Ford Health

Abstract Preview: Purpose: To develop and validate an open-source Python package for fast, widely compatible, and user-friendly photon dose calculation algorithm through comparisons with clinical treatment planning sys...

Analyzer-Less X-Ray Interferometry with Super-Resolution Methods

Authors: Joyoni Dey, Hunter Cole Meyer, Murtuza Taqi

Affiliation: Louisiana State University

Abstract Preview: Purpose: We propose using super-resolution methods for X-ray grating interferometry without an analyzer with detectors that fail to meet the Nyquist sampling rate needed for traditional image recovery...

Applicability of Online Dose Measurement in Trilogy Linear Accelerators: Using Target Current Pulse Counting Method

Authors: Daming LI, Jinsen Xie, Zhe Zhang

Affiliation: Peking University Shenzhen Hospital Radiotherapy Department, School of Nuclear Science and Technology, University of South China

Abstract Preview: Purpose:
This study aims to investigate the feasibility of online dose measurement of the Trilogy linear accelerator output based on target current pulse signals.
Methods:
A data acquisition ...

Automatic Specific Absorption Rate (SAR) Prediction for Hyperthermia Treatment Planning (HTP) Using Deep Learning Method

Authors: Yankun Lang, Lei Ren, Dario B. Rodrigues

Affiliation: University of Maryland School of Medicine, Department of Radiation Oncology, University of Maryland School of Medicine

Abstract Preview: Purpose:
HTP of microwave (MW) phased-array systems determine MW antenna settings to maximize energy absorption (SAR in W/kg) in tumor. Conventional HTP algorithms calculate SAR based on electromag...

BEST IN PHYSICS IMAGING: Volumetric Sampling Properties of Longitudinal Multiple X-Ray-Source Array Computed Tomography (MXA-CT)

Authors: Craig K Abbey, John M. Boone, Richard E. Colbeth, Andrew M. Hernandez, Vance Robinson, Paul Schwoebel, Jeffrey H. Siewerdsen, Alejandro Sisniega, Wojciech B. Zbijewski, Huanyi Zhou

Affiliation: UC Santa Barbara, University of California, UT MD Anderson Cancer Center, Johns Hopkins University, University of New Mexico Albuquerque, UC Davis Health, Varex Imaging Corporation

Abstract Preview: Purpose: A new CT configuration utilizing a multiple X-ray-source array (MXA) is under development to mitigate cone-beam (CB) artifacts in single-rotation wide coverage imaging. We investigate the sam...

BEST IN PHYSICS MULTI-DISCIPLINARY: Evaluation of Spot-Level N-12 PET Imaging for Online Range Verification in Multi-Field Intensity Modulated Proton Therapy

Authors: Zahra Ahmadi Ganjeh, Stefan Both, Peter Dendooven, Jeffrey Free, Brian Zapien Campos

Affiliation: Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Particle Therapy Research Center (PARTREC), Department of Radiation Oncology, University Medical Center Groningen, University of Groningen

Abstract Preview: Purpose: Positron emission tomography (PET) has been investigated for range monitoring in intensity-modulated proton therapy (IMPT), but real-time feedback been limited due to the focus on long-lived ...

Characterization of Novel Shielded and Unshielded Silicon Diode Detectors for Photon and Electron Dosimetry in Radiation Therapy

Authors: Mohamad Ahmad Alissa, Carson Brame, Damian Czarnecki, Olivier Evrard, Charbel A. Habib, Jeff Hildreth, Andy Murray, Andreas Schönfeld, Ann-Britt Schönfeld, David Towle, Gerd Wessing

Affiliation: CDT-West - Centrum für Diagnostik und Therapie, Radiologie Vechta, Technische Hochschule Mittelhessen, MyMichigan Health, Sun Nuclear Corp., Mirion Technologies

Abstract Preview: Purpose: To characterize the performance of novel shielded and unshielded silicon diode detectors in relative photon and electron beam dosimetry.

Methods: The novel shielded and unshielded sili...

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...

Directional Dependence of Detectors for Beam Profiles and Output Factors in Small Field Dosimetry

Authors: Indra J. Das, Ahtesham Ullah Khan, Andrew J. White

Affiliation: Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin - Madison, Northwestern Memorial Hospital, Northwestern University Feinberg School of Medicine

Abstract Preview: Purpose: Small field dosimetry presents challenges due to lateral disequilibrium and the selection of suitable detectors. Volume averaging and density corrections hamper accurate profile measurements....

Enhancing Dosimetric Conformity in Single-Energy Bragg Peak Flash Therapy Using Aperture-Based Techniqu

Authors: Chin-Cheng Chen, Chingyun Cheng, Longfei Diao, Benjamin Durkee, Minglei Kang, Haibo Lin, LeLe Liu, Yangguang Ma, Xuanqin Mou, YunTong Pei, Charles B. Simone, YuFei Wang, Xueqing Yan, Xingyi Zhao, Wang Zhengda

Affiliation: Peking University, St. Jude Children's Research Hospital, New York Proton Center, Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Department of Radiation Oncology, The First Affiliated Hospital of Zhengzhou University, School of Software Engineering, Xi’an Jiaotong University, School of information and communications engineering, Faculty of electronic and information engineering, Xi’an Jiaotong University, Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Department of Human Oncology, University of Wisconsin-Madison

Abstract Preview: Purpose: This study evaluates the effectiveness of apertures in improving lateral dose falloff in proton pencil beam scanning (PBS) single-energy Bragg peak (SEBP) FLASH radiotherapy (RT). The approac...

Exploring the Universal Correlation between DNA Damage Distribution and Cell Surviving Fraction in Photon, Proton, and Carbon Ion Irradiations

Authors: Lawrence F. Bronk, Fada Guan, Xun Jia, Youfang Lai, Miao Qi

Affiliation: Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Johns Hopkins University, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center

Abstract Preview: Purpose: DNA double-strand breaks (DSBs) are widely regarded as critical indicators of cellular response to ionizing radiation. This study aims to establish a direct, unbiased and universal correlatio...

Feasibility of Producing GRID Therapy Dosimetry Using a Compact Linac Treatment Head with Pencil Beam Scanning

Authors: Yiran Liu, Zhengzheng Liu, Fang-Fang Yin

Affiliation: Duke Kunshan Univeristy, Huazhong University of Science and Technology, Medical Physics Graduate Program, Duke Kunshan University

Abstract Preview: Purpose: To investigate the feasibility of producing high dose rate GRID therapy using a compact linear accelerator (LINAC) treatment head with scanning beam and stationary grid collimator.
Methods...

Field Output Correction Factors of Novel Shielded and Unshielded Silicon Diode Detectors

Authors: Mohamad Ahmad Alissa, Carson Brame, Damian Czarnecki, Olivier Evrard, Charbel A. Habib, Jeff Hildreth, Andy Murray, Andreas Schönfeld, Ann-Britt Schönfeld, David Towle, Gerd Wessing

Affiliation: CDT-West - Centrum für Diagnostik und Therapie, Radiologie Vechta, Technische Hochschule Mittelhessen, MyMichigan Health, Sun Nuclear Corp., Mirion Technologies

Abstract Preview: Purpose: To characterize field output correction factors of novel shielded and unshielded silicon diode detectors.
Methods: Novel shielded and unshielded Silicon Diode Detectors (SDD) were characte...

Generalizable 7T T1 Map Synthesis from 1.5T and 3T T1W MRI for High-Resolution MRI-Guided Radiation Therapy

Authors: Zachary Buchwald, Chih-Wei Chang, Zach Eidex, Hui Mao, Richard L.J. Qiu, Justin R. Roper, Mojtaba Safari, Hui-Kuo Shu, Xiaofeng Yang, David Yu

Affiliation: Emory University and Winship Cancer Institute, Emory University, Department of Radiation Oncology and Winship Cancer Institute, Emory University, Emory University School of Medicine

Abstract Preview: Purpose: MRI-guided radiation therapy (MRgRT) benefits significantly from enhanced soft-tissue contrast and spatial resolution, which aid in accurately delineating tumors and organs at risk. Although ...

Geometrically Derived Density Compensation Function for 3D Non-Cartesian MRI Reconstruction

Authors: Oluyemi Bright Aboyewa, KyungPyo Hong, Daniel Kim

Affiliation: Department of Radiology, Northwestern University

Abstract Preview: Purpose: While non-Cartesian MRI is desirable for fast imaging with high spatial resolution and robustness to motion, it requires long post-processing times. Preconditioning with an adequate density c...

Impact of Breathing Trace on Gating Uncertainty

Authors: William P. Donahue, Lauren Smith, Shu (Stella) Xing

Affiliation: Department of Medical Physics, Memorial Sloan Kettering Cancer Center

Abstract Preview: Purpose: To quantify the dosimetric uncertainty of end-exhale gating as a function of breathing pattern.

Methods: A Truebeam delivered AP square fields to EBT4 film placed in the Quasar MRI4D M...

Impact of Jaw Reproducibility and Source Occlusion on Small Field Dosimetry

Authors: Mylinh Dang, Indra J. Das, George X. Ding, Ahtesham Ullah U Khan, Andrew J. White

Affiliation: Northwestern Memorial Hospital, Northwestern University Feinberg School of Medicine, Northwestern Medicine, Vanderbilt University Medical Center

Abstract Preview: Purpose: The large variability in field output factor (FOF) observed among various studies is speculated to be due to uncertainty in jaw reproducibility that is linked directly with source occlusion. ...

Implementation of a Virtual Quality Assurance System Using Raystation for Online MR-Linac Adaptive Radiotherapy

Authors: Min-Sig Hwang, Danny K. Lee, Daniel C. Pavord, Kyung Lim Yun

Affiliation: Allegheny Health Network

Abstract Preview: Purpose: Ensuring the quality of treatment plans through patient-specific pre-treatment quality assurance (QA) is essential. However, the use of physical phantom-based QA devices is not feasible for o...

Improving Adversarial Approaches to Synthetic CT Image Generation with Skin Surface Masks

Authors: Mahya Ahmadzadeh, Nagarajan Kandasamy, Keyur Shah, Gregory C. Sharp, Santhosh Vadivel, John MacLaren Walsh

Affiliation: Electrical and Computer Engineering Department, Massachusetts General Hospital, Emory University, Drexel University

Abstract Preview: Purpose: In image-guided radiotherapy (IGRT), cone beam CTs (CBCTs) suffer from distortions that degrade registration with planning CTs. While CycleGANs can generate synthetic CTs (sCTs) from CBCTs, e...

Inverse Geometry Photon Counting CBCT

Authors: Saree Alnaghy, Owen Thomas Dillon, Sean P Hood, Paul J. Keall, Ricky O'Brien, Tess Reynolds

Affiliation: Image X Institute, Faculty of Medicine and Health, The University of Sydney, University of Wollongong, Medical Radiations, School of Health and Biomedical Sciences, RMIT University

Abstract Preview: Purpose: Photon Counting Detectors (PCDs) have been demonstrated to improve resolution, contrast and lesion detectability in fan-beam CT. There is naturally a desire to bring these improvements to Con...

Log File-Based Patient-Specific QA As a Viable Alternative to Measurement-Based QA in IMPT

Authors: Sina Mossahebi, Pouya Sabouri, Kayla Schneider, James W Snider

Affiliation: University of Maryland School of Medicine, Proton International, Department of Radiation Oncology, University of Arkansas for Medical Sciences (UAMS), Department of Radiation Oncology, University of Arkansas for Medical Sciences

Abstract Preview: Purpose:
Conventional patient-specific QA (PSQA) for intensity-modulated proton therapy (IMPT) requires extensive measurements, straining resources in single-room proton centers. This study evaluat...

Multi-Center Diffusion-Weighted MRI Validation for 0.35T MR-Linac: A Repeatability and Reproducibility Study

Authors: Tess Armstrong, Nema Bassiri, Alonso N. Gutierrez, Michael Kasper, Natalia Lutsik, Eric Mellon, Kathryn E. Mittauer, Siamak P. Nejad-Davarani, Shyam Pokharel, Suresh Rana, Hui Wang, Joseph Weygand

Affiliation: Department of Radiation Oncology and Applied Science, Dartmouth Health, Miami Cancer Institute, Baptist Health South Florida, ViewRay, Inc., Miami Cancer Institute, Lynn Cancer Institute, Boca Raton Regional Hospital, Baptist Health South Florida, Department of Radiation Oncology, University of Miami

Abstract Preview: Purpose: Radiation treatments on the MR-linac (MRL) enable daily acquisition of anatomical and physiological images for adaptive treatment planning. The apparent diffusion coefficient (ADC) estimated ...

Off-Axis Dependency of the Sun Nuclear MapCheck3 Diode Array

Authors: Alyssa Gadsby, William J. Godwin, Daniel G. McDonald, Jean L. Peng, Alek K. Rapchak, Sean A Roles, Austin M. Skinner, Stephanie Tan

Affiliation: Medical University of South Carolina

Abstract Preview: Purpose: The Sun Nuclear MapCheck3 device is used for patient-specific QA. While it is typically employed in perpendicular field-by-field delivery using the Isocentric Mounting Fixture, fields not ful...

Optimization of Impulsed Acquisition Protocols on 1.5T MRI Using Simulation-Based Bayesian Experimental Design for Cell Size Imaging

Authors: Yan Dai, Jie Deng, Xun Jia, Wen Li, Junzhong Xu

Affiliation: Johns Hopkins University, Medical Artificial Intelligence and Automation (MAIA) Lab & Department of Radiation Oncology, UT Southwestern Medical Center, Department of Radiology, Vanderbilt University Medical Center, Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Medical Artificial Intelligence and Automation (MAIA) Laboratory, Department of Radiation Oncology, UT Southwestern Medical Center

Abstract Preview: Purpose: Cell size is a vital parameter in evaluating the tumor microenvironment, including cell apoptosis and radiotherapy(RT)-induced immune cell infiltration. The IMPULSED(Imaging Microstructural P...

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...

Real-Time 3D Visualization of Electric Field with Electroacoustic Tomography

Authors: Jadon O Buller, Yankun Lang, Liangzhong Xiang, Andrea Paulina Yanez

Affiliation: University of Maryland School of Medicine, University of California, Irvine

Abstract Preview: Purpose: With the widespread adoption of electroporation, there is growing interest in deep-tissue electric field monitoring. Electroporation therapy ablates target regions by generating electric fiel...

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...