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Results for "5mm shift": 62 found

60RPM Rotational Winston Lutz Test to Characterize Operational MV-Kv Offset on Reflexion X1 System

Authors: Huixiao Chen, Ethan Hartowicz, Lichung Ku, Tim Perez, Ray Yang

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

Abstract Preview: Purpose: To characterize MV-kV isocenter offset on a novel ring gantry radiotherapy system where the Linac, PET, kV-CT, and MV imaging subsystems rotate together at native operating speed of 60RPM.

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 Pilot Study to Implement a Definitive Breast SBRT Technique

Authors: Charmainne Cruje, Maria Dumol, Nawroz Fatima, Marisa Finlay, Kalaina Johnson, Raman Mohla, Jasleen Uppal

Affiliation: Trillium Health Partners, Carlo Fidani Regional Cancer Centre

Abstract Preview: Purpose: To evaluate the robustness of a breast SBRT protocol in achieving target coverage by utilizing online- and retrospectively-matched CBCT-to-CT images.
Methods: The first pilot patient was s...

A Real-Time Framework for Fiducial Tracking and Intrafraction Motion Assessment of Cyberknife in Stereotactic Body Radiation Therapy for Liver Cancer

Authors: Ruiyan Du, Mingzhu Li, Ying Li, Wei Liu, Shihuan Qin, Yiming Ren, Biao Tu, Hui Xu, Lian Zhang, Xiao Zhang, Zengren Zhao

Affiliation: Department of General Surgery, Hebei Key Laboratory of Colorectal Cancer Precision Diagnosis and Treatment, The First Hospital of Hebei Medical University, Medical AI Lab, The First Hospital of Hebei Medical University, Hebei Provincial Engineering Research Center for AI-Based Cancer Treatment Decision-Making, The First Hospital of Hebei Medical University, Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Department of Radiation Oncology, Mayo Clinic, Department of Oncology, The First Hospital of Hebei Medical University

Abstract Preview: Purpose: Fiducial tracking is widely used in CyberKnife to dynamically guide the gantry for moving target like liver cancer stereotactic body radiation therapy (SBRT). This study developed a robust fr...

Advancing Cardiac Sparing with Upright Patient Geometry and Deep Learning

Authors: Shae Gans, Carri K. Glide-Hurst, Mark Pankuch, Chase Ruff, Niek Schreuder, Nicholas R. Summerfield, Yuhao Yan

Affiliation: Departments of Human Oncology and Medical Physics, University of Wisconsin-Madison, Northwestern Medicine Proton Center, Northwestern Medicine Chicago Proton Center, Leo Cancer Care

Abstract Preview: Purpose: Novel upright patient positioners coupled with diagnostic-quality vertical CT at treatment isocenter introduce a significant opportunity for improved image-guided particle therapy. Treating p...

An Agglomerative Clustering-Based Program for Optimizing Multiple-Target SRS Treatment Planning

Authors: Josephine Chen, CheukKai Becket Hui, Yildirim D. Mutaf

Affiliation: Kaiser Permanente

Abstract Preview: Purpose:
To demonstrate the effectiveness of a target clustering program in generating cluster configurations and isocenter placements for multiple brain lesions in SRS treatment planning, with the...

Assessing the Impact of Intrafraction Shifts on Critical OAR Doses in a Standardized Spine SBRT Program

Authors: Daniel A. Alexander, Anish Butala, Anthony Austin Kassaee, Neil Malhotra, Ian Messing, Gabrielle W Peters, Ryan M. Scheuermann

Affiliation: Department of Radiation Oncology and Applied Sciences, University of Pennsylvania

Abstract Preview: Purpose: Stereotactic Body Radiation Therapy (SBRT) for spinal metastases uses CBCT-based localization and highly conformal treatment delivery to increase the biologically equivalent dose to the targe...

Assessment of the Auto Registration Feature of the PET/CT Linac Used for Biology Guided Radiation Therapy (BGRT)

Authors: Emily Hansen, Tyler Kaulfers, Alois M. Ndlovu, Francia Romero, Niara Rowe, Roland Teboh

Affiliation: Montefiore Einstein University Hospital, Hackensack University Medical Center

Abstract Preview: Purpose: Daily use and reliance on the auto registration feature requires a performance check. Clinical application of auto registration is performed without a selected region of interest (ROI), requi...

Automated Tool for Radiotherapy Initial Patient Setup: A Robust Approach Based on Vertebral Identification

Authors: Hailun Pan, Yingli Yang, Jie Zhang, Yibin Zhang

Affiliation: Department of Radiation Oncology,Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Department of Radiology, Ruijin Hospital, Department of Radiation Oncology, Ruijin Hospital, , Shanghai Jiaotong University School Of Medicine, Shanghai United imaging Healthcare Advanced Technology Research Institute

Abstract Preview: Purpose: Accurate patient positioning is critical in radiotherapy (RT) to ensure effective treatment delivery and minimize harming surrounding healthy tissues. Vertebral misalignment during RT setup h...

Automatic Tumor Segmentation and Catheter Detection from MRI for Cervical Cancer Brachytherapy Using Uncertainty-Aware Dual Convolution-Transformer Unet

Authors: Majd Antaki, Rohini Bhatia, Gayoung Kim, Yosef Landman, Junghoon Lee, Akila N. Viswanathan

Affiliation: Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Physics and Advanced Development Elekta

Abstract Preview: Purpose: Brachytherapy is a standard radiation therapy approach for cervical cancer, which directly delivers radiation source to the tumor using catheters. Treatment planning requires identification o...

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 ...

CBCT and Exactrac Dynamic Agreement for Patient Positioning during Spine SRS/SBRT Treatments

Authors: Martha J. Malin, Matthew Schelin

Affiliation: NYU Langone Health

Abstract Preview: Purpose: To evaluate the agreement between ExacTrac Dynamic (ETD) and CBCT-based positioning for spine SRS/SBRT treatments during initial patient setup and repositioning after intrafraction motion.

Can We Use Smaller Margin for the Planned Target Volume with Adaptive Radiotherapy?

Authors: Mahmoud H Abdelgawad, Shahabeddin mostafanazhad Aslmarand, Lili Chen, Xiaoming Chen, Ahmed A. Eldib, Teh Lin, Chang Ming Charlie Ma, Robert A. Price

Affiliation: Physics department, Faculty of science, Al-Azhar University, Fox Chase Cancer Center

Abstract Preview: Purpose: Many modern radiotherapy clinics are moving to online adaptive radiotherapy. A recent upgrade of the CBCT-based adaptive radiotherapy system introduced ultra-high-speed image acquisition. Thi...

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...

Comparison of Mlc Off-Axis Characteristics for Eclipse AAA v18 and v16 Using Portal Dosimetry

Authors: Junsheng Cao, Khushdeep Singh

Affiliation: Overlook Medical Center

Abstract Preview: Purpose: Eclipse v18 introduces Enhanced Leaf Modeling for MLCs. This study investigates the MLC off-axis characteristics using portal dosimetry
Methods:
MLC characteristics were analyzed for th...

Comparison of Patient Localization on Visionrt Alignrt and Varian Identify

Authors: Ahmed A. Eldib, Teh Lin, Chang Ming Charlie Ma

Affiliation: Fox Chase Cancer Center

Abstract Preview: Purpose: Surface imaging has been used clinically more regularly. The accuracy of several commercial products has been studied. AAPM TG302 also has proposed the system quality assurance and commission...

Deep Learning-Based Segmentation Using Cine Epid Images for Real-Time Tumor Monitoring

Authors: Fumiaki Komatsu, Shunsuke Moriya, Ryosuke Nakamura, Takeji Sakae, Toshiyuki Terunuma, Tetsuya Tomita

Affiliation: Graduate School of Comprehensive Human Sciences, University of Tsukuba, Institute of Medicine, University of Tsukuba, Proton Medical Research Center, University of Tsukuba, Department of Radiology, University of Tsukuba Hospital

Abstract Preview: Purpose: To develop a deep learning (DL) model capable of accurately tracking lung tumors independent of beam angle variations.
Methods: A thoracic dynamic phantom simulating lung motion in the sup...

Design and Testing of a 3D-Winston-Lutz Phantom to Quantify Isocentricity of Pencil Beam Scanning Proton Therapy Machines

Authors: Imad M. Ali, Nesreen Alsbou, Baraa Kalani

Affiliation: Oklahoma State University, University of Central Oklahoma, University of Oklahoma Health Sciences Center

Abstract Preview: Purpose: To develop a three-dimensional Winston-Lutz phantom to quantify the isocentricity of the gantry, couch, and on-board imager of the MEVION-S250i proton therapy machine.
Methods: A 3D-scinti...

Design of Filtimator (Filter + Collimator) for CBCT of Pediatric Cancer Patients Receiving Proton Therapy

Authors: Soon N. Huh, Perry B. Johnson, Jiyeon Park, Ryan Stevens

Affiliation: University of Florida Health Proton Therapy Institute, UF Health Proton Therapy Institute, UFHPTI

Abstract Preview: Purpose:
Cone-beam computed tomography (CBCT) doses shall be limited for pediatric patients in clinical settings. Device called Filtimator (filter+collimator) was custom designed to reduce setup CB...

Determining the Effect of Motion during Gamma Knife Stereotactic Radiosurgery on Anterior and Posterior Lesions Using an Anthropomorphic Phantom

Authors: Guang-Pei Chen, Nitish Chopra, Juan A. Garcia-Alvarez, Mi Huang, Slade J. Klawikowski, Haidy G. Nasief, George A. Noid, Abdul Parchur, Eric S. Paulson, Christina M. Sarosiek, Christopher Schultz

Affiliation: Department of Radiation Oncology, Medical College of Wisconsin

Abstract Preview: Purpose: During routine delivery of mask-based Gamma Knife (GK) SRS, motion is tracked via the position of a reflective sticker placed on the patient’s nose relative to two stationary reflectors on th...

Direct Table Rotational Isocenter Determination Using Radiation Isocenter

Authors: Christopher Ackerman, Chang Chang, Yansong Liu, Stephen Kenneth Northway, Bailey Vallejo

Affiliation: University of California San Diego / California Protons, California Protons Cancer Therapy Center, California Proton Cancer Therapy Center

Abstract Preview: Purpose: To determine mechanical isocenter of a 6-degree-of-freedom (6DOF) couch using radiation isocenter. Coincidence between the isocenters is quantified using MyQA Phoenix amorphous silicon detect...

Dosimetric Comparative Analysis of Modulated and Non Modulated Electron Bolus in Nasal Electron Therapy

Authors: Stephen D. Davis, Alonso N. Gutierrez, Noah S. Kalman, Michael Leyva, Alejandro Rene Llanes Lopez, William Romaguera, Ranjini P. Tolakanahalli, Deborah Wang

Affiliation: Miami Cancer Institute, Baptist Health South Florida, Miami Cancer Institute, Miami Cancer Institute, Baptist Health

Abstract Preview: Purpose: To evaluate whether a modulated electron bolus (MEB) technique improves both nominal and shifted dose distributions in nasal electron therapy as compared to a non‑modulated, uniform‑thickness...

Dosimetric Effect of Patient Positioning Errors in Dual-Isocenter VMAT for Bilateral Breast Cancer Treatment: A Quantitative Assessment

Authors: Awens Alphonse, Nebi Demez, Noufal Manthala Padannayil, Haley Park, Shyam Pokharel, Suresh Rana, Lauren A. Rigsby, Nishan Shrestha, Somol Sunny

Affiliation: Florida Atlantic University, Lynn Cancer Institute, Boca Raton Regional Hospital, Baptist Health South Florida

Abstract Preview: Purpose: This study evaluates the dosimetric effects of patient positioning errors, including setup inaccuracies and yaw deviations, on dual-isocenter volumetric modulated arc therapy (VMAT) plans for...

Dosimetric Evaluation of Comprehensive Motion Management in 1.5T MR-Linac for Real-Time Gated Radiotherapy

Authors: Kin Yin Cheung, Chen-Yu Huang, Chi Wah Kong, Ka Ki Lau, Pei-Xiong Li, Pak Hang Nam, Mei Yan Tse, Jierong Wang, Bin Yang, Siu Ki Yu, Jing Yuan, Chi To Yung, Shang Peng Felix Yung

Affiliation: Medical Physics Department, Hong Kong Sanatorium and Hospital, Research Department, Hong Kong Sanatorium and Hospital

Abstract Preview: Purpose: Intrafraction motion management remains a major challenge in magnetic resonance-guided radiotherapy (MRgRT). The recent clinical release of an active motion management system aims to enhance ...

Dosimetry Comparison of Surface-Guided and Orthogonal X-Ray Film-Based Setups for Proton Pencil-Beam Scanning in Breast Cancer Treatment

Authors: Darren Kaplan, Chenguang Liu, Mark Pankuch

Affiliation: Northwestern Medicine Proton Center

Abstract Preview: Purpose: This study evaluates the hypothesis that surface-guided radiation therapy for the breast or chest wall using proton PBS provides comparable target coverage and OARs sparing to x-ray-based IGR...

Dynamic Winston-Lutz Testing for FFF Beams

Authors: Cambridge L Bui-Nguyen, Alexander S. Nguyen, Liqiang (Lee) Tao

Affiliation: Varian AOS @Epic Care, UC Berkeley

Abstract Preview: Purpose: Dynamic Winston-Lutz (WL) testing provides a comprehensive framework for evaluating the accuracy of isocenter alignment. This study investigates the impact of dynamic beam modulation, such as...

Estimation of Brain Tumor’s Intra-Fraction Movement during Radiosurgery Using Fiducial Markers on the Skin Surface – a Simulation Study

Authors: Damien C. Mathew, Brandon Hai Nguyen, Satwik Pani, Yoichi Watanabe

Affiliation: Minnespolis Radiation Oncology, Department of Radiation Oncology, University of Minnesota Medical School, Washington University

Abstract Preview: Purpose: To formulate a computational algorithm to quantify the tumor movement from the motion data of landmarks on the brain surface. To estimate the magnitude of tumor movement when the head makes a...

Evaluating Dose Variability in Bladder Contouring for MR-Guided Prostate Cancer Radiotherapy

Authors: Emily Helen Hayes, Chihray Liu

Affiliation: University of Florida

Abstract Preview: Purpose: To evaluate dosimetric discrepancies in bladder dose calculations among rigid, deformed, and manual contouring methods in prostate cancer patients and assess dose variations resulting from bl...

Evaluating the Aktina Isopoint System for Quality Assurance in Linear Accelerators

Authors: Blessing Chinelo Akah, Daniel W. Neck, David J. Perrin, Sotirios Stathakis

Affiliation: Mary Bird Perkins Cancer Center

Abstract Preview: Purpose: To assess the reliability of the Aktina Isopoint software in evaluating different components of the linear accelerator for optimized quality assurance and linac performance
Methods: The Ak...

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...

First in-Vivo Application of a Novel Precision Small Animal Irradiation Platform with Proton IMPT Delivery and Advanced on-Board Image-Guidance

Authors: Niels Bassler, Jonathan Bortfeldt, Davide Boscaini, Francesco Evangelista, Guyue Hu, Ze Huang, Margarita Kozak, Julie Lascaud, Giulio Lovatti, Eero LÜnnqvist, Jasper Nijkamp, Munetaka Nitta, Prasannakumar Palaniappan, Katia Parodi, Marco Pinto, Per R. Poulsen, Marco Riboldi, Babak Sharifi, Brita Singers Sørensen, Peter Thirolf

Affiliation: Department of Medical Physics, Ludwig-Maximilians-Universität Mßnchen (LMU Munich), Ludwig-Maximilians Universität, Danish Centre for Particle Therapy, Aarhus University Hospital, Department of Medical Physics, Ludwig-Maximilians-Universität (LMU) Mßnchen, Department of Experimental Clinical Oncology, Aarhus University, Department of Oncology, Aarhus University Hospital

Abstract Preview: Purpose: To perform the first in vivo application of a novel small animal radiation research platform combining on-board image-guidance with multi-field intensity modulated spot scanning delivery [1] ...

Four-Dimensional Computed Tomography Based on 16cm-Long Detectors Vs 4cm-Long Detectors: Dose Validation

Authors: Qianyi Xu, Inhwan Yeo

Affiliation: INOVA Schar Cancer Institute, Thomas Jefferson University

Abstract Preview: Purpose:
Four-dimensional computed tomography(4DCT) is prone to a geometrical error when respiration changes upon patient shift. 4DCT with a longer-length detector(16cm), uninvolving the shift, has...

Imaging Preclinical Proton Flash Radiation Using a Small Animal PET System

Authors: Xun Jia, Heng Li, Wen Li, Devin Miles, Daniel Sforza, Lingshu Yin, Yuncheng Zhong

Affiliation: Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Johns Hopkins University

Abstract Preview: Purpose: FLASH therapy holds great potential to revolutionize radiotherapy by minimizing toxicities of normal tissues. The extraordinarily high dose rate of FLASH proton beam makes precise delivery to...

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 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...

Impact of Tracking By Jaws or Mlc on Treatment Accuracy in Synchrony Modality for Tomohelical Technique

Authors: Mireille Conrad, CĂŠdric De Marco, Marie Fargier-Voiron, Maud Jaccard, Oscar Matzinger, Anthony Nagy, StĂŠphane Nevesny, Nicolas Joel Lionel Perichon

Affiliation: Clinique De Genolier

Abstract Preview: Purpose: Real-time tracking is implemented on Radixact by detecting the target position with 2D-kV image either directly (for lung tumors), or indirectly (using fiducials as surrogates), and by adapti...

Improved SNR and Estimation Accuracy for Deuterium-MRI Acquired with Chemical Shift Imaging at 7 Tesla

Authors: Muhammed AR Anjum, Andrew J. Fagan

Affiliation: Mayo Clinic

Abstract Preview: Purpose:
This study describes a novel post-processing method to boost image SNR for deuterium-MRI acquired using chemical shift imaging (CSI) at 7T. Deuterium MRI via exogenous administration of a ...

Margins to Account for Cardiac and Respiratory Motion in Cardiac Radioablation

Authors: Alanah M. Bergman, Marc W Deyell, Tania Karan, Jakob Marshall, Justin Poon, Devin Schellenberg, Steven Thomas, Richard Thompson

Affiliation: University of British Columbia, University of Alberta, BC Cancer

Abstract Preview: Purpose: A conservative approach to account for random errors due to intra-fraction cardiac and respiratory motion during cardiac radioablation (CR) is to define a margin equal to the amplitude of car...

Mask-Less Adaptable Headrest for Head-and-Neck Radiotherapy

Authors: Alyssa Capizzi, John J Dombrowski, Nabil N. Khater

Affiliation: Saint Louis University

Abstract Preview: Purpose: To evaluate a mask-less adaptable headrest (MAHR) prototype for head-and-neck IMRT designed to reduce random and systematic shifts of patients’ setups. MAHR complements current image-guidance...

Minimizing Positioning Errors in Intracranial SRS: The Role of Verification Imaging after 6-Dof Corrections

Authors: Anthony J. Doemer, Yimei Huang, Benjamin Movsas, Ellen Park, Mira Shah, Salim Siddiqui, Karen C. Snyder, Kundan S Thind, Bo Zhao

Affiliation: Henry Ford Health

Abstract Preview: Purpose: The 6 degrees-of-freedom (6-DoF) robotic couch is considered essential for linac-based stereotactic radiosurgery (SRS), particularly for irregularly shaped targets adjacent to critical organs...

Multi-Vendor Linac Isocenter Evaluation: Implications for SRS in Radiotherapy

Authors: Blessing Chinelo Akah, Brad Barhorst, Daniel W. Neck, David J. Perrin, Chad Robertson, Sotirios Stathakis

Affiliation: Mary Bird Perkins Cancer Center

Abstract Preview: Purpose: To evaluate the performance and radiation isocenter of Elekta and Varian linear accelerator using Aktina Isopoint.
Methods: The Aktina Isopoint was used to measure the physical and radiati...

Needle-in-Needle Technique: A Lifeline for HDR Syed Interstitial Implants with Unusable Catheters

Authors: Jochen Cammin, Yushi Chang, Mariana Guerrero, Kai Jiang, Narottam Lamichhane, Elizabeth Nichols

Affiliation: Department of Radiation Oncology, UT Southwestern Medical Center, University of Maryland School of Medicine, Department of Radiation Oncology, University of Maryland School of Medicine

Abstract Preview: Purpose: Our institution handles a large GYN SYED patient load (5 HDR fractions over 3 days). In recent years, we faced many logistical challenges, such as broken/contaminated catheters, which disrupt...

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...

On the Sensitivity Evaluation of End-to-End Test in Radiotherapy

Authors: Yussuf A. Abdelal, Sebastien A. Gros, Luke Layman, Anil Sethi

Affiliation: Stritch School of Medicine, Cardinal Bernardin Cancer Center, Loyola University Chicago, Department of Radiation Oncology, Stritch School of Medicine, Loyola University Chicago

Abstract Preview: Purpose:
End-to-end (E2E) test is a vital QA check of the overall radiotherapy process from simulation imaging to treatment delivery. Although clinical passing criteria are available, guidelines on...

PET Guided Radiation Therapy for Large Planning Target Volume Expansions of Small PET-Active Gross Tumor Volumes

Authors: Sarah Dumont, Trevor Ketcherside, An Liu, William T. Watkins, Qiuyun Xu

Affiliation: RefleXion Medical, Department of Radiation Oncology, City of Hope National Medical Center

Abstract Preview: Purpose:
The RefleXion X1 SCINTIX algorithm convolves beam fluence with real-time PET distributions for tracking and plan adaptation, but radiotherapy Planning Target Volumes (PTVs) are often signi...

Patient-Specific Bio-Morphological Features in Cherenkov Imaging for Positioning Verification: A Retrospective Analysis in Accelerated Partial Breast Irradiation (aPBI) VMAT Radiotherapy

Authors: Yao Chen, Lesley A Jarvis, Allison Matous, Rongxiao Zhang

Affiliation: Dartmouth College, University of Missouri, Dartmouth Cancer Center, Dartmouth Health

Abstract Preview: Purpose: Precise patient positioning is critical in accelerated partial breast irradiation (aPBI) to ensure accurate dose delivery to the tumor bed while minimizing exposure to surrounding healthy tis...

Population Level Robustness Evaluation for Establishment of Benchmarks for Optimized Plans for Prostate Proton Therapy

Authors: Laura Buchanan, Samantha G. Hedrick, Stephen L. Mahan, Isabella Pfeiffer, Chester R. Ramsey, Taylor Ransom

Affiliation: Thompson Proton Center, University of Tennessee

Abstract Preview: Purpose: Proton pencil beam scanning can reduce normal tissue dose but is highly sensitive to setup, anatomical changes, and range variations. These uncertainties may compromise target coverage and or...

Positional Accuracy and Clinical Recommendations for HDR Brachytherapy Ring Applicators: A Commissioning and Evaluation Study

Authors: Peter G. Maxim, Michael P. Reilly, Mengying Shi, Maryam Shirmohammad, Darren M. Zuro

Affiliation: University of California Irvine

Abstract Preview: Purpose: This study aims to assess the positional accuracy of HDR brachytherapy ring applicators, quantify the extent of positional deviation, and provide clinical recommendations for GYN HDR brachyth...

Prior-Informed Neural Super-Resolution Dosimetry for Radiotherapy QA from Sparse Dosimeter Arrays

Authors: Muhammad Ramish Ashraf, Clinton Gibson, Gregory Szalkowski, Lei Wang, Siqi Wang, Lei Xing

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

Abstract Preview: Purpose: To develop a neural network-based super-resolution framework for enhancing the resolution of sparse dosimetry measurements in patient-specific radiotherapy QA. Sparse detector arrays, such as...

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...

Prostate SBRT Motion Study and PTV Margin Evaluation with Exactrac Fiducial Tracking

Authors: Ahmad K. Al-Basheer, Andrew Clarke Grice, Kelly E. Hosier, Mark Logsdon, Evan A. Silverstein, Chris Tunnicliff, Chuan Wu

Affiliation: Sutter Medical Foundation, Sutter Health

Abstract Preview: Purpose: For Prostate SBRT Boost treatments, determine whether a uniform 2mm CTV to PTV margin is sufficient to give 95% dose coverage to the CTV in 90% of patients via a modified Van Herk Margin Form...

Quantitative Image Review Metric for Vertebral Body Misalignment

Authors: Luis E. Fong de los Santos, Douglas John Moseley, Satomi Shiraishi, Cenji Yu

Affiliation: Mayo Clinic

Abstract Preview: Purpose: To quantitatively detect errors in vertebral body localization using normalized cross correlation (NCC)

Methods: Volumetric images of a thoracic end-to-end SBRT phantom with a removabl...

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...

The Biological TCP/NTCP Modelling on Oropharyngeal Head-and-Neck Cancer for Patients Treated with Proton Beam Therapy

Authors: Wen C. Hsi, Tae Kyu Lee, Biniam Yo Tesfamicael

Affiliation: Allina Health, Department of Radiation Oncology, University of Arkansas for Medical Sciences (UAMS), Oklahoma Proton Center

Abstract Preview: Purpose: When minimal dose-variations induced by inter-fractional anatomical-changes and positioning-deviation were found for having limited impact on clinic-outcomes of oropharyngeal head-and-neck (H...

Three-Dimensional Reconstruction of Triggered Images with Dehazing Algorithm for Precise Intrafraction Motion Detection in Spine SBRT

Authors: Hyosung Cho, Dae Yup Han, Duhee Jeon, Jiwon Park, Hyesun Yang

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

Abstract Preview: Purpose: To precisely detect intrafraction patient motion during spine stereotactic body radiotherapy (SBRT) treatment delivery, we propose an optimized technique for three-dimensional reconstruction ...

Towards Arbitrary Phantom Patient Specific IMRT QA on Reflexion X1

Authors: Andrew Groll, Ayan Mitra, PhD, Manoj Narayanan, Sanchit Sharma, Ray Yang, Timothy Pok Chi Yeung

Affiliation: Reflexion Medical Inc,, RefleXion Medical

Abstract Preview: Purpose: To develop a versatile QA tool enabling dose recalculation of a patient’s plan sinogram redeployed onto arbitrary replacement phantom geometry, and extract computed dose along detector planes...

Two-Element Complementary Sensor for out-of-Plane Tracking in MR-Guided Radiotherapy

Authors: Zhaohui Han, Piotr Zygmanski

Affiliation: Brigham and Women’s Hospital, Dana Farber Cancer Institute, Harvard Medical School, Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute, Harvard Medical School

Abstract Preview: Purpose: Real-time motion tracking/gating are oftentimes limited to a single sagittal plane on many magnetic resonance linear accelerators (MR-Linac). Out-of-plane motion is therefore difficult to det...

Ultra-Sparse-View Cone-Beam CT Reconstruction Based Strictly-Structure-Preserved Deep Neural Network in Image-Guided Radiation Therapy

Authors: Guangjun Li, Ying Song, Huanan Tang, Tianxiong Wu, Qiuyi Ye, Wei Zhang

Affiliation: West China Second Hospital of Sichuan University, United Imaging Healthcare, West China Hospital of Sichuan University

Abstract Preview: Purpose:
To propose a general low-dose reconstruction model for ultra-sparse-view cone-beam CT (CBCT) and evaluate its clinical application in improving image quality and reducing radiation dose fo...

Uncertainty Analysis of Hyperarc VMAT Plans for Stereotactic Radiosurgery Patients with Multiple Brain Metastases

Authors: Shifeng Chen, Yannick P. Poirier, Huijun Xu, Byong Yong Yi, Baoshe Zhang, Hong Zhang, Jinghao Zhou

Affiliation: University of Maryland School of Medicine, University of Maryland Shore Regional Cancer Center, Vanderbilt University Medical Center, Department of Radiation Oncology, University of Maryland School of Medicine, Capital Region Medical Center

Abstract Preview: Purpose: To thoroughly assess the resilience of HyperArc VMAT plans for multiple brain metastases (MBT) in relation to (i) high-definition MLC leaf positional inaccuracies and (ii) patient rotational ...

Use of Radiopaque Rectal Spacer for IGRT – a Preliminary Analysis of Alignment Accuracy and Interobserver Variability

Authors: Joseph A. Miccio, Nicholas J. Potter, Zain Siddiqui

Affiliation: Penn State Health Milton S. Hershey Medical Center

Abstract Preview: Purpose: Fiducial markers are the gold standard for prostate alignment during CT-based image-guided radiotherapy (IGRT). Radiopaque hydrogel rectal spacers reduce rectal toxicity by displacing the rec...

Using Varian’s Obi Tools to Develop a CBCT Workflow with Triggered Imaging for Spine SBRT Intrafraction Motion Monitoring

Authors: Yi An, David J. Carlson, Zhe (Jay) Chen, Jun Deng, Dae Yup Han, Sameer Taneja

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

Abstract Preview: Purpose: Spine Stereotactic radiosurgery (SSR) delivers a large radiation dose and utilizes narrow PTV margins, on the order of 1 mm, to avoid excess dose to the spinal cord. Because of this, intrafra...

Variations in Radiation Isocenter Offsets from the Winston-Lutz Test Performed on Different Photon Energies

Authors: Cambridge L Bui-Nguyen, Alexander S. Nguyen, Liqiang (Lee) Tao

Affiliation: Varian AOS @Epic Care, UC Berkeley

Abstract Preview: Purpose: To quantity variations in Winston Lutz (WL) test results due to different energies used in SBRT, SRT or SRS.
Methods: A WL phantom with a 6.4 mm diameter center radio-opaque sphere is used...