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Results for "non uniformity": 30 found

3D Printing Assisted Collimator Design for Fan Beam-Based X-Ray Fluorescence Tomographic Imaging

Authors: Brett Bocian, Nesrin Dogan, John C. Ford, Alan Pollack, Ryder Marshall Schmidt, Junwei Shi, Jorge D Vega

Affiliation: University of Miami, University of Miami Sylvester Comprehensive Cancer Center

Abstract Preview: Purpose: X-ray fluorescence computed tomography (XFCT) is an emerging molecular imaging modality gaining attention in cancer theranostics with high-Z metal nanoparticles (MNPs). While XFCT has been de...

A Deep Learning Method for Direct Vmi Inference Using a Dual-Layer Radiotherapy Kv-CBCT Imager

Authors: Ross I. Berbeco, Vera Birrer, Raphael Bruegger, Pablo Corral Arroyo, Roshanak Etemadpour, Dianne M. Ferguson, Rony Fueglistaller, Thomas C. Harris, Yue-Houng Hu, Matthew W. Jacobson, Mathias Lehmann, Nicholas Lowther, Daniel Morf, Marios Myronakis

Affiliation: Brigham and Women's Hospital, Harvard Medial School, Dana-Farber Cancer Institute, Department of Radiation Oncology, Dana Farber/Brigham and Women's Cancer Center, Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Brigham and Womens Hospital, Dana Farber Cancer Institute, Harvard Medical School, Brigham and Women's Hospital, Varian Imaging Laboratory, Dana-Farber Cancer Institute

Abstract Preview: Purpose: A challenge for dual energy CBCT is that noise and residual errors in material decomposition steps can become amplified when forming low energy, high contrast virtual mono-energetic images (V...

A Novel Linac Onboard Dual-Layer Kv Imager Provides Increased Clinical CBCT Contrast and Metal Artifact Reduction Using Virtual Monoenergetic Images

Authors: Ross I. Berbeco, Vera Birrer, Raphael Bruegger, Pablo Corral Arroyo, Roshanak Etemadpour, Dianne M. Ferguson, Rony Fueglistaller, Thomas C. Harris, Yue-Houng Hu, Matthew W. Jacobson, Mathias Lehmann, Marios Myronakis

Affiliation: Brigham and Women's Hospital, Harvard Medial School, Dana-Farber Cancer Institute, Department of Radiation Oncology, Dana Farber/Brigham and Women's Cancer Center, Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Brigham and Women's Hospital, Varian Imaging Laboratory, Dana-Farber Cancer Institute

Abstract Preview: Purpose: Dual-energy imaging offers benefits, including metal artifact reductions (MAR) and improved contrast, that enhance visualization. Currently, dual-energy imaging is largely limited to CT scann...

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 Simplified, Rigorous Procedure for Ultrasound Quality Assurance

Authors: Paul L. Carson, Sander Dekker, Stephen Z Pinter, Megan K. Russ

Affiliation: Clinical Imaging Physics Group, Department of Radiology, Duke University Health System, University of Michigan, Cablon Medical B.V., Univ of Michigan, Dept. of Radiology

Abstract Preview: Purpose:
To promote a simplified, inexpensive, but rigorous set of ultrasound QA tests and to evaluate their potential using a Randomly-placed very Hypoechoic Sphere Phantom (RHSP) in comparison to...

AI-Driven Early Detection of Digital Radiography Performance Degradation: A Predictive Quality Control Approach

Authors: Giovanni Iacca, Gloria Miori, Laura Orsingher, Daniele Ravanelli, Annalisa Trianni

Affiliation: Department of Information Engineering and Computer Science, University of Trento, Medical Physics Department, S.Chiara Hospital, APSS

Abstract Preview: Purpose: This study aims to leverage artificial intelligence (AI) to predict and identify performance degradation in Digital Radiography (DR) systems, enabling proactive maintenance and minimizing cli...

An Efficient, Low-Cost, and Accessible Film Dosimetry Scanning System

Authors: Parminder S. Basran, Wyatt Flanders, Skylar Sylvester

Affiliation: Cornell University

Abstract Preview: Purpose: To develop a reliable, efficient, and low-cost methodology for quantifying radiation doses using radiochromic film and a custom-built lightbox and to evaluate the system's performance compare...

Comprehensive Evaluation of High-Performance Cone-Beam Computed Tomography on C-Arm and Ring-Gantry Linacs for Adaptive Radiation Therapy

Authors: Laura I. Cervino, Karen Episcopia, Hsiang-Chi Kuo, Sangkyu Lee, Seng Boh Gary Lim, Shih-Chi Lin, Grace Tang

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

Abstract Preview: Purpose: This study evaluated the performance of the HyperSight Cone-Beam Computed Tomography (CBCT) system on a TrueBeam C-arm LINAC (TB) and two Ethos ring-gantry LINACs (ES) for adaptive radiation ...

Computational Prototype Single-Channel Vaginal Cylinder with Integrated Filter to Address Dose Uniformity in High-Dose-Rate Brachytherapy for Endometrial Cancer

Authors: Brett Bocian, Patrick James Jensen, Luis Augusto Perles, Christopher J. Tien

Affiliation: Yale University School of Medicine, University of Miami, The University of Texas MD Anderson Cancer Center, UT MD Anderson Cancer Center

Abstract Preview: Purpose: Guidelines for dose prescriptions in endometrial cancer are based upon depth from the cylinder, traditionally 5 mm or 0 mm (i.e., surface). There are no current single-channel vaginal cylinde...

Conformal Flash for Large Treatment Fields

Authors: Julien Forthomme, Carolina Llina Fuentes, Valentin Hamaide, Lucian Hotoiu, Rudi Labarbe, Rasmus Nilsson, Arnaud Pin, Francois Vander Stappen, Erik Traneus

Affiliation: RaySearch Laboratories AB, Ion Beam Applications SA

Abstract Preview: Purpose: Conformal FLASH achieves ultra-high-dose-rate (UHDR) proton therapy (>40 Gy/sec) by scanning a mono-energetic pencil beam through accessories (range shifter, Conformal Energy Modulator, apert...

Correlation between Imaging Dose and Image Quality for Hypersight CBCT

Authors: Stephen Bhagroo, Sorour Hosseini, YuHuei Jessica Huang, Jeremy Kunz, Thomas Boyd Martin, Geoffrey S. Nelson, Nicholas Pierre Nelson, Ryan G. Price, Hui Zhao

Affiliation: University of Utah, Department of Radiation Oncology, Huntsman Cancer Institute, University of Utah

Abstract Preview: Purpose: To investigate the correlation between HyperSight CBCT imaging dose and image quality.
Methods: Six-series of 174 CBCT scans were acquired using HyperSight on Halcyon (125kV, 133-971mAs, F...

Development of an Inverse Treatment Planning System for Precision Small Animal Radiotherapy

Authors: Zihao Liu, Qiwei Wu, Yanfei Xiong, Yidong Yang, Ning Zhao

Affiliation: Department of Engineering and Applied Physics, School of Physical Sciences, University of Science and Technology of China, Department of Engineering and Applied Physics, University of Science and Technology of China, University of Science and Technology of China

Abstract Preview: Purpose: To develop an inverse planning framework that optimizes beam angles and intensities for small animal radiotherapy and to validate its accuracy and effectiveness.
Methods: The inverse plann...

Dose Evaluation of Multiple Gammatiles in Heterogeneous Brain Models Using Egs_Brachy

Authors: Fatemeh Akbari, Artemis Dalby, Nelson A. Miksys, Prarthana Pasricha, Rowan M. Thomson

Affiliation: Ackerman Cancer Center, Carleton University

Abstract Preview: Purpose: To investigate dose evaluations for GammaTile brachytherapy, a novel treatment for brain malignancies. The analysis focuses on the impact of tissue heterogeneities, including the presence of ...

Dose Rate Measurements of Scanning Carbon Ion Beams Using a Plastic Scintillator Detector

Authors: Motohiro Kawashima, Adrian Kugara, Masao Nakao, Shuichi Ozawa, Mutsumi Tashiro, Maria Varnava

Affiliation: Gunma University Heavy Ion Medical Center, Hiroshima High-Precision Radiotherapy Cancer Center

Abstract Preview: Purpose: This study aimed to evaluate the time-dependent dose rate characteristics of a scanning carbon ion beam using a fast-response plastic scintillator detector (PSD), with a focus on its potentia...

Dosimetric Characteristics of a Commercially Available Platinum Cured Silicone Rubber Material As a Custom Bolus Option

Authors: Jordan B Lunsford, Sagar Pokhrel, Ashkan Shafiee, Curtis S. Whiddon

Affiliation: Atrium Health Wake Forest Baptist, University of North Carolina, Atrium Health Wake Forest Baptist High Point Medical Center

Abstract Preview: Purpose: To investigate the dosimetric characteristics of a platinum cured silicone rubber material (Platsil) for use as custom bolus in radiotherapy
Methods: Sheets of 2, 4, 6, and 8 mm Platsil we...

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 Evaluation of the Aldo Function for Multiple Brain Metastases in Automated Stereotactic Radiosurgery Treatment Planning

Authors: Hsiao-Mei Fu, Shih-Ming Hsu, Chia-Ting Lee, Shih-Hua Liu, Tsung-Yu Yen

Affiliation: National Yang Ming Chiao Tung University, Mackay Memorial Hospital

Abstract Preview: Purpose: The Automatic Lower Dose Objective (ALDO) is a unique function designed to achieve 98% relative coverage across all targets in automated SRS treatment planning (HyperArc planning). This study...

Dosimetry Commissioning of a Commercial Cabinet X-Ray Irradiator for Small Animal Irradiation

Authors: Sang Hyun Cho, Amrit Kaphle, Sunil Krishnan, Neerajan Nepal

Affiliation: The University of Texas MD Anderson Cancer Center, The University of Texas Health Science Center

Abstract Preview: Purpose: To determine the basic dosimetry parameters and characteristics of a commercial cabinet x-ray unit for small animal irradiation as well as the specific dosimetry parameters for concurrent irr...

Evaluating the Impact of Beam Spot Spacing on Dose Rates and Field Uniformity for Small Animal Proton Ultra-High Dose Rate Irradiation

Authors: Jack Biondo, Audrey Magness, Anthony E. Mascia, Zhiyan Xiao, Yongbin Zhang

Affiliation: Cincinnati Children's Proton Therapy Center

Abstract Preview: Purpose: Proton FLASH-RT has shown promise reducing normal tissue toxicity while maintaining tumor control. However, in vivo experiments critically depend on achieving ultra-high dose rate (UHDR) and ...

Feasibility of a Normoxic N-Vinylpyrrolidone-Based Polymer Gel (VIPET) Dosimeter for Three-Dimensional Proton Beam Measurements

Authors: Yoshihiko Hoshino, Kenji Hotta, Taeko Matsuura, Ai Nakaoka, Hidenobu Tachibana

Affiliation: Hokkaido University, Department of Radiology, Gunma University Hospital, Radiation Safety and Quality Assurance Division, National Cancer Center Hospital East

Abstract Preview: Purpose: Gel dosimeters enable three-dimensional dose measurements, but no reports have evaluated the fundamental performance of VIPER-type gel dosimeters in proton beam measurements. Therefore, we ev...

Impact of Beamline Mis-Adjustment Following Central Beamline Replacement for Halcyon Linear Accelerator

Authors: Emily Y. Hirata, Xiaoyu Sherry Liu, Evan Porter, Manju Sharma

Affiliation: University of California San Francisco, University of California, San Francisco, University of California

Abstract Preview: Purpose: Introduced in 2018, the Varian Halcyon platform has increased in popularity due to its reduced cost, user-friendly design, and operational efficiency. As this platform ages, major repairs, in...

In-Vivo Image Quality of Head/Neck and CNS with an Advanced C-Arm Linac CBCT Solution

Authors: Theodore Higgins Arsenault, Kenneth W. Gregg, Lauren E Henke, Rojano Kashani, Christian Erik Petersen, Alex T. Price, Atefeh Rezaei, Runyon C. Woods

Affiliation: University Hospitals Seidman Cancer Center

Abstract Preview: Purpose: CBCT is subject to more artifacts due to increased photon scatter, especially in areas of increased tissue heterogeneities compared to fan-beam CTs (FBCTs). Improved imaging panels combined w...

Long-Term Stability Assessment of an Imaging Ring System Using One Year of Monthly Quality Assurance Data

Authors: Awens Alphonse, Nebi Demez, Brian P. Laffey, Shyam Pokharel, Suresh Rana, Nishan Shrestha

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

Abstract Preview: Purpose: The Imaging Ring is a mobile digital X-ray system capable of producing 2D planar X-rays, fluoroscopy, and 3D Cone-Beam Computed Tomography (CBCT) images. This study aimed to evaluate the long...

Preclinical Dosimetric Evaluation for Small Animal Study to Investigate Normal Tissue-Sparing Effects in the Electron Ultra-High Dose-Rate (FLASH) Environment

Authors: Ashok Bhandari, Andrew Joseph Fanning, Kyle J. Gallagher, Brendan Graff, Christopher Jenkins, Kyuhak Oh, Ying Yan, Su-Min Zhou

Affiliation: University of Nebraska Medical Center

Abstract Preview: Purpose: This study aimed to design a robust experimental setup to ensure accurate dose delivery using ultra-high-dose-rate for small animal experiments by conducting dosimetric evaluations prior to a...

Rapid 3D Prototyped Solid-Source Phantoms for Quality Assurance of Biology-Guided Radiotherapy (BgRT)

Authors: Jon Burns, Andrew Groll, Gopinath Kuduvalli, Thomas Laurence, Manoj Narayanan, Jeffrey Schmall, Sanchit Sharma

Affiliation: RefleXion Medical

Abstract Preview: Purpose: To simplify BgRT testing we have developed techniques that use 3D resin printed structures that can be filled with Ge-68 epoxy. This approach allows the development of highly complex, clinica...

Rectal Spacer Injection on the Day of HDR Prostate Brachytherapy Enhances Dosimetry and Reduces Rectal Dose for Patients Receiving Combined Brachytherapy and EBRT.

Authors: Francis A Asamoah, David D. Campos, Jordan A Holmes, Ke Colin Huang, Omar Ishaq, Sook Kien Ng, Arpan Prabhu, Edwin Quashie, Yong Yue

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

Abstract Preview: Purpose: Evaluate a novel rectal spacer workflow with spacer injection during brachytherapy to streamline logistics, reduce hospital visits and costs, and compare the benefits of SpaceOAR Vue and Barr...

Relative Optimized Linearization for Film Dosimetry with Non-Uniformity Correction

Authors: Piotr Pater, Nicholas G. Zacharopoulos

Affiliation: McGill University, Medical Physics Unit, Gerald Bronfman Department of Oncology, McGill University

Abstract Preview: Purpose: To develop a method for accurate relative film dosimetry that incorporates non-uniformity
corrections.
Methods: The accuracy of Devic’s [1] linearization approach was evaluated using si...

Scissor-Beam Based Carbon Ion Minibeam Treatment Planning Method

Authors: Hao Gao, Qiang Li, Yuting Lin, Wei Wang, Wei Wu, Weijie Zhang

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

Abstract Preview: Purpose: Carbon minibeam radiation therapy (cMBRT) offers high peak-to-valley dose ratio (PVDR) and relative biological effectiveness. A key challenge is balancing uniform target coverage with PVDR pr...

Simulation Design of a Dedicated Head Coil for Enhanced EPT Imaging to Map the Electrical Properties of Tumor Tissues

Authors: Jingyao Chen, Yingli Yang, Jie Zhang

Affiliation: Department of Radiology, Ruijin Hospital, Shanghai Ruijin Hospital, Shanghai United imaging Healthcare Advanced Technology Research Institute

Abstract Preview: Purpose: Magnetic Resonance Electrical Properties Tomography (MR EPT) is a method to spatially mapping the conductivity and permittivity based on small B1 field changes after the imaged object was int...

Streamlining Hippocampal-Sparing Whole-Brain VMAT Planning: Enhancing Efficiency and Plan Quality with an Automated Workflow

Authors: Eric C. Ford, Yulun He, Minsun Kim, Dustin Melancon, Juergen Meyer, Dong Joo Rhee, Yinghua Tao

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

Abstract Preview: Purpose: To develop and evaluate an automated-planning technique capable of generating high-quality treatment plans for hippocampal-sparing-whole-brain radiation therapy.
Methods: An auto-planning ...