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Results for "lower pass": 31 found

A Five-Year Retrospective Analysis of Dose Reduction for the Top 10 Adult CT Protocols

Authors: Emi Ai Eastman, Christina Lee, Xinhua Li, Yifang (Jimmy) Zhou

Affiliation: Cedars-Sinai Medical Center

Abstract Preview: Purpose:
This study aimed to retrospectively evaluate dose reduction efforts in past five years using acquisition-level data and to compare the results with ACR achievable dose (AD) and dose refere...

Absolute Measurement of HDR Ir-192 Air-Kerma Strength Using an Exradin A3 Known-Volume Ionization Chamber

Authors: Larry A. DeWerd, Sean Jollota, Karen Rex Pius Vincent

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

Abstract Preview: Purpose: Absolute measurements, often used to establish primary standards, offer lower measurement uncertainty. For 192Ir high-dose-rate (HDR) brachytherapy, the interim primary standard for air-kerma...

An Evaluation of an SRS Quality Assurance System for Complex Patient Plans.

Authors: John Bennet, Indrin J. Chetty, Tai H. Dou

Affiliation: Department of Radiation Oncology,Cedars Sinai Medical Center, Department of Radiation Oncology, Cedars Sinai Medical Center, Department of Radiation Oncology,Cedars-Sinai Medical Center

Abstract Preview: Purpose:
To investigate the effect of complexity of stereotactic radiosurgery (SRS) volumetric modulated arc therapy plans on gamma pass rates (GPR) using a novel high-resolution ion chamber array ...

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...

Automated Treatment Planning for Linac-Based Stereotactic Radiosurgery of Intraocular Malignancies Via Hyperarc Knowledge-Based Planning

Authors: Chase Cochran, Shane McCarthy, Damodar Pokhrel, William St Clair

Affiliation: University of Kentucky, Department of Radiation Medicine, University of Kentucky, Radiation Medicine

Abstract Preview: Purpose: Manually generating intraocular stereotactic radiosurgery (SRS) plans involves significant challenges, including lengthy planning times and inter-planner variability. Knowledge-based SRS plan...

BEST IN PHYSICS MULTI-DISCIPLINARY: Motion-Resolved Dynamic CBCT Reconstruction Using Prior-Model-Free Spatiotemporal Gaussian Representation (PMF-STGR)

Authors: Hua-Chieh Shao, Chenyang Shen, 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: Motion-resolved CBCT imaging, which reconstructs a dynamic sequence of CBCTs reflecting intra-scan motion (one CBCT per x-ray projection), is highly desired for regular/irregular motion chara...

Benchmarking Patient Doses for Barium Fluoroscopy Procedures: A Single-Institution Study

Authors: Wilfred R Furtado, Gary Y. Ge, Jie Zhang

Affiliation: Department of Radiology, University of Kentucky, University of Kentucky

Abstract Preview: Purpose: The United Kingdom and several other countries already have well-established diagnostic reference levels (DRLs) for gastrointestinal fluoroscopic procedures, whereas the United States does no...

Comparison of CBCT Dose Calculation Accuracy between Truebeam Hypersight Image Reconstruction Algorithms

Authors: Sarah Aubert, Harald Keller, Jeff D. Winter

Affiliation: Princess Margaret Cancer Centre

Abstract Preview: Purpose: Support for treatment planning directly on CBCT imaging on C-arm linacs will enable adaptive radiation therapy (ART) capacity with increased treatment technique flexibility. The HyperSight im...

Creation of Pass-through Proton Minibeams Using a Single Quadrupole Magnet

Authors: Abdullah A. Alshreef, Grant A. McAuley, Jerry D Slater

Affiliation: Loma Linda University Medical Center, Loma Linda University

Abstract Preview: Purpose: In this project we investigate the use of a single permanent magnet quadrupole to create pass-through proton minibeams suitable for potential clinical use and preclinical radiobiology experim...

Dedicated Cone-Beam Breast CT: Investigation on the Effect of Lesion Type on Detectability Index Using Cascaded Systems Analysis.

Authors: Jing-Tzyh Alan Chiang, Andrew Karellas, Thomas C Larsen, Hsin Wu Tseng, Srinivasan Vedantham

Affiliation: Department of Biomedical Engineering, The University of Arizona, Department of Medical Imaging, The University of Arizona

Abstract Preview: Purpose: To investigate the performance of dedicated breast computed tomography (BCT) for the the tasks of detection of soft tissue lesions and microcalcifications using cascaded systems analysis. The...

Determination of HU Override for Small Metal Implants in Proton Therapy

Authors: Matthew Stephen Andriotty, Taoran Cui, Harold Y Hu, Ke Nie, Tan Phan, Xiao Wang, Ning J. Yue, Chengzhu Zhang

Affiliation: Rutgers Cancer Institute of New Jersey, Basis Scottsdale

Abstract Preview: Purpose: Metallic implants are often non-isocentric, and their exact volumes/orientations/shapes are difficult to capture and contour accurately on CT images even if that information is known beforeha...

Development and Validation of a Deep Learning-Based Auto-Segmentation Module for Vestibular Schwannoma

Authors: John Byun, Steven D Chang, Cynthia Fu-Yu Chuang, Xuejun Gu, Melanie Hayden Gephart, Yusuke Hori, Fred Lam, Gordon Li, Lianli Liu, Weiguo Lu, David Park, Erqi Pollom, Elham Rahimy, Deyaaldeen Abu Reesh, Scott Soltys, Gregory Szalkowski, Lei Wang, Xianghua Ye, Kangning Zhang

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

Abstract Preview: Purpose: Accurate and automated delineation of vestibular schwannoma (VS) volume is crucial for disease management, as both treatment approaches (stereotactic radiosurgery and invasive surgery) and mo...

Difference in Image Quality between Natively Reconstructed and PACS Reformatted CT Images

Authors: Beth Reed, Justin B. Solomon

Affiliation: Duke University, Clinical Imaging Physics Group, Department of Radiology, Duke University Health System

Abstract Preview: Purpose: The purpose of this study was to compare image quality between CT images of variable slice thickness reconstructed directly at the scanner verses reformatted at a PACS workstation.
Methods...

Direct-to-Unit Dose Calculations for Stereotactic Radiosurgery on a C-Arm Linac with Modern on-Board Imaging Solutions

Authors: Theodore Higgins Arsenault, Kenneth W. Gregg, Lauren E Henke, Rojano Kashani, Haley K Perlow, Alex T. Price, Atefeh Rezaei, Prashant Vempati, Runyon C. Woods

Affiliation: University Hospitals Seidman Cancer Center

Abstract Preview: Purpose: The HyperSight imaging feature on C-arm linacs(HS-CBCT) offers increased CT number accuracy over conventional on-board imaging. The C-arm geometry allows for noncoplanar treatments common to ...

Enhancing Daily QC for Photon-Counting CT: Incorporating 40 keV VMI Evaluations with the ACR CT Phantom

Authors: Lakshmi Ananthakrishnan, Xinhui Duan, Liqiang Ren, Gary Xu, Kuan Zhang, Yue Zhang

Affiliation: Department of Radiology, UT Southwestern Medical Center, Imaging Services, UT Southwestern Medical Center

Abstract Preview: Purpose: Daily quality control (QC) programs for diagnostic CT include water CT number (HU), standard deviation (SD), and visual artifact evaluations. At our institution, 70 keV virtual monoenergetic ...

Evaluation of Treatment Planning Feasibility and Dosimetric Quality of the Reflexion™ X1 System for Complex Spinal Targets

Authors: Thomas I. Banks, Bin Cai, Andrew R. Godley, Yang Kyun Park, Hao Peng, Rameshwar Prasad, Chenyang Shen, Shunyu Yan, Haozhao Zhang

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

Abstract Preview: Purpose:
The RefleXion® X1 (RefleXion Medical, Inc., Hayward, CA) uniquely integrates KVCT and PET as on-board image guidance for radiotherapy. It has been installed and commissioned for clinical u...

GPU-Accelerated Beamlet and Full Dose Calculations for Efficient Radiation Therapy Planning

Authors: Girish Bal, Jan Kralj, Ayan Mitra, PhD, Ling Shao, Matjaz Subic, Yevgen Voronenko

Affiliation: RefleXion Medical, Cosylab

Abstract Preview: Purpose: This work enhances the efficiency of radiation therapy treatment planning by optimizing the beamlet dose matrix and full patient dose computations using GPU acceleration. The Collapsed-Cone C...

Improving Patient Safety with MRI Visible Laterality Markers

Authors: Ndey Badjan, Chris Beasley, Issack Boru, Josh Joyner, Erica Owenby, Scott H. Robertson, Nicholas Said

Affiliation: Duke University Health System

Abstract Preview: Purpose:
To design MRI-visible laterality markers to boost patient safety by minimizing errors in laterality and subsequent procedures.
Methods:
The markers were made using commercially avail...

Inter-Patient Registration Methods for Voxel-Based Analysis in Lung Cancer

Authors: Chloe Min Seo Choi, Joseph O. Deasy, Jue Jiang, Sudharsan Madhavan, Nikhil Mankuzhy, Nishant Nadkarni, Andreas Rimner, Maria Thor, Harini Veeraraghavan, Abraham Wu

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

Abstract Preview: Purpose: Voxel-based analysis (VBA) requires accurate topology-preserving inter-patient deformable image registration (DIR). This study assessed whether guiding a DIR method with geometric priors of t...

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-Vendor Validation of a Deep Learning-Based Synthetic CT Generation Model for MR-Only Radiotherapy Planning in the Pelvis

Authors: Gregory Bolard, Rabten Datsang, Sarah Ghandour, Timo Kiljunen, Pauliina Paavilainen, Sami Suilamo, Katlin Tiigi

Affiliation: Turku University Hospital, Virginia Commonwealth University, MVision AI, North Estonia Medical Centre, Docrates Cancer Center, Hopital Riviera-Chablais

Abstract Preview: Purpose: To verify the performance of a vendor-neutral deep learning model for synthetic CT generation from T2-weighted and balanced steady-state MR sequences to support both MR-only simulation and MR...

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...

Predicting Proton Therapy Dose Delivery Accuracy: A Machine Learning Approach Using Iroc’s Proton Phantom Data

Authors: Lian Duan, Stephen F. Kry, Hunter S. Mehrens, Paige A. Taylor

Affiliation: The University of Texas MD Anderson Cancer Center, UT MD Anderson Cancer Center

Abstract Preview: Purpose: To develop a machine learning model for predicting dose delivery accuracy and identifying its key factors in IROC’s proton phantom program.
Methods: IROC’s proton QA program has six proton...

Radial Waveguide Structures for Enhanced Power Transmission Efficiency in Dielectric Wall Accelerators

Authors: Julien Bancheri, Chau Giang Bui, David G Cooke, Christopher M Lund, Morgan J Maher, Jan P. Seuntjens, Jason Z Yuan

Affiliation: Princess Margaret Cancer Centre & University of Toronto, Medical Biophysics, University of Toronto, University of Toronto, Medical Physics Unit, McGill University, Department of Physics, McGill University

Abstract Preview: Purpose: The dielectric wall accelerator (DWA) offers a low-cost solution for proton therapy, using non-resonant waveguides to accelerate particles. Radial waveguides (RWGs), consisting of a dielectri...

The Feasibility of Ethos-Based Pulsed Reduced Dose-Rate (PRDR) Radiotherapy

Authors: Chia-Lung Chien, Renteng Hou, Wen C. Hsi, Faraz Kalantari, Ganesh Narayanasamy, Zhong Su

Affiliation: University of Arkansas for Medical Sciences, Department of Radiation Oncology, University of Arkansas for Medical Sciences (UAMS)

Abstract Preview: Purpose:
PRDR is an effective re-irradiation treatment for patients who have already reached the tolerance dose to their organs at risk (OARs). While PRDR is implemented on TrueBeam by limiting the...

Two's Company, Three's a Crowd? a Bayesian Approach to Optimizing the Number of Measurement Readings in Radiation Therapy QA

Authors: Siyong Kim, Ava Paek, Joseph B. Schulz, James J. Sohn, Eric D. Stolen, Ethan D. Stolen

Affiliation: Department of Radiation & Cellular Oncology, University of Chicago, University of Central Florida, Virginia Commonwealth University, Department of Radiation and Cellular Oncology, University of Chicago, Department of Radiation Oncology, Stanford University School of Medicine

Abstract Preview: Purpose: The American Association of Physicists in Medicine Task Group 142 (AAPM TG-142) guidelines recommend three measurements during monthly quality assurance to keep results within two standard de...

Uncertainty Analysis for Effective Dose Conversion Factors in CT

Authors: Renxin Chu, Jelena Mihailovic, Kai Yang, Lifeng Yu, Da Zhang

Affiliation: Massachusetts General Hospital, Mayo Clinic, Boston Children's Hospital, UVA Health University Hospital, University of Missouri Health Care

Abstract Preview: Purpose:
A frequently used method to estimate effective dose (ED) in CT is by multiplying the dose length product (DLP) by a conversion factor, known as k-factor. The k-factor in this method is sus...

Uncertainty in Contralateral Breast Dose Reconstruction for Breast Cancer Radiotherapy Patients in the United States between 1990 and 2012

Authors: Amy Berrington de Gonzalez, David Borrego, Rochelle Curtis, Gretchen L Gierach, Jae Won Jung, Choonik Lee, Choonsik Lee, Matthew Mille, Lene Veiga, Jacqueline Vo

Affiliation: University of Michigan, East Carolina University, Radiation Protection Division, Office of Radiation and Indoor Air, U.S. Environmental Protection Agency, National Cancer Institute, Institute of Cancer Research

Abstract Preview: Purpose: Radiotherapy is vital for treating breast cancer, but its long-term health effects remain a concern. Accurate dose reconstruction is crucial for evaluating risks in retrospective epidemiologi...

Utilizing Bladder Ultrasound to Estimate on-Table Bladder Volume in Prostate Cancer SBRT: Impact on Treatment Setup Consistency and Dosimetric Outcomes

Authors: Minsong Cao, Amar Kishan, Dylan P. O'Connell, Jonathan Pham, Michael Steinberg, Luca F Valle, Michael Xiang

Affiliation: Department of Radiation Oncology, University of California, Los Angeles

Abstract Preview: Purpose: To evaluate bladder ultrasound as a surrogate for estimating on-table bladder volume in prostate cancer patients undergoing stereotactic body radiation therapy (SBRT). The study aimed to asse...

Validating a Pre-Existing CT HU-to-Mass Density Curve for Direct Dose Calculation on High Quality Cbcts

Authors: Casey E. Bojechko, Tricia Chinnery, Grace Gwe-Ya Kim, Xenia Ray

Affiliation: University of California San Diego

Abstract Preview: Purpose: To evaluate the use of a calibration curve generated from the CT simulator for direct dose calculation on cone beam computed tomography (CBCT) images taken with the on-board imaging system. T...

Volumetric-Modulated Arc Therapy (VMAT) Is Associated with Improved Dose Homogeneity, but More Normal Tissue Irradiation Compared to Three-Dimensional Conformal Radiation Therapy (3DCRT) for Breast Cancer

Authors: Laura I. Cervino, Linda X. Hong, Jessica Pagan, Angelica A. Perez-Andujar, Maria Thor

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

Abstract Preview: Purpose: Three-dimensional conformal radiotherapy (3DCRT) and Volumetric-Modulated Arc Therapy (VMAT) are used to treat locally advanced breast cancer. The 3DCRT treatment plans use the treatment fiel...