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Results for "7mv fff": 42 found

6FFF Beam Output Trend Showing Target Degradation

Authors: Sean L. Berry, Hsiang-Chi Kuo, Seng Boh Gary Lim, Ingrid Valencia Lozano, Laszlo Voros

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

Abstract Preview: Purpose:
To quantify the impact of target degradation on 6FFF beam output by analyzing the output trends and adjustment frequencies at our clinic on a flattening filter-free (6FFF) and a flattened ...

A Novel Sphere Packing Solution Via Principal Component Analysis for Lattice SFRT Treatment of Large, Bulky, and Unresectable Tumors

Authors: James Robert Castle, Joshua Misa, Damodar Pokhrel, William St. Clair

Affiliation: University of Kentucky, Department of Radiation Medicine

Abstract Preview: Purpose: We propose a novel methodology for lattice deployment in spatially fractionated radiotherapy (SFRT), using principal component analysis (PCA) to improve sphere packing within the tumor. Impro...

A Predictive Tool for Optimizing Treatment System Allocation in Hypofractionated Whole-Breast Radiotherapy

Authors: Zhenzhen Dai, Anthony J. Doemer, Ryan Hall, Kenneth Levin, Bing Luo, Benjamin Movsas, Karen C. Snyder, Kundan S Thind, Eleanor Walker

Affiliation: Henry Ford Health, HFHS

Abstract Preview: Purpose: To investigate the feasibility of a predictive tool for efficient allocation of hypofractionated whole-breast irradiation patients between Varian Truebeam and Ethos systems.
Methods: A ful...

An Analytical Approach to Monitor Unit Calculation in Extended Distance Total Body Irradiation (TBI)

Authors: Cheewai Cheng, Indra J. Das, Jeffrey Yui Hei Wong, Poonam Yadav

Affiliation: Northwestern Memorial Hospital, Northwestern University Feinberg School of Medicine

Abstract Preview: Purpose: Radiation treatment machine replacement brings chaos and urgency of timely completion of machine commissioning for every procedure used including TBI that are time consuming. Based on past ex...

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...

Characterization, Commissioning, and Clinical Evaluation of a Commercial Beo Optically Stimulated Luminescence (OSL) System

Authors: Brett G Erickson, Joseph P. Kowalski, Xinyi Li, Qiuwen Wu, Sua Yoo

Affiliation: Duke University, Mayo Clinic - Department of Radiation Oncology, Duke University Medical Center

Abstract Preview: Purpose: Characterization and commissioning of the BeO-based myOSLchip system was performed (per TG191) to assess its feasibility as a full replacement for the recalled Landauer aluminum oxide OSL in ...

Cherenkov to Dose Trends with Small Field Beams

Authors: Jeremy Eric Hallett, Aubrey Parks, Brian W Pogue

Affiliation: University of Wisconsin - Madison, University of Wisconsin-Madison

Abstract Preview: Purpose: Cherenkov imaging visualizes radiotherapy beams, assuming emission is proportional to deposited dose. However, attempts for Cherenkov as a quantitative dose estimation have been unsuccessful ...

Commissioning of a 3D-CRT Planning Software for a Machine with Only Flattening-Filter Free Energy

Authors: Michalis Aristophanous, Steven Blum, Laura I. Cervino, Antonio L. Damato, Karen Episcopia, Chi Huang, Shih-Chi Lin, Michelle K. Savacool

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

Abstract Preview: Purpose: Varian Ethos (Varian Medical Systems, Palo Alto, CA) is a 6 MV flattening-filter-free (FFF) only machine, posing a challenge in creating homogeneous dose distributions when using manual 3D-CR...

Commissioning of a Near Real-Time In Vivo Film Dosimetry System

Authors: Maria F. Chan, Indra J. Das, Xiuxiu He, Seng Boh Gary Lim, Jeonghoon Park, Yunjie Yang

Affiliation: Department of Medical Physics, Memorial Sloan Kettering Cancer Center, Northwestern Memorial Hospital, Northwestern University Feinberg School of Medicine, Memorial Sloan Kettering Cancer Center

Abstract Preview: Purpose: There is a need for accurate and flexible in-vivo dosimetry systems, particularly for special procedures. Effective dosimetry is crucial for dose verification and maintaining records. A new r...

Commissioning, Validation and Pilot Study of New Rpld System for Dosimetry Audits in Bulgaria

Authors: Gueorgui Gueorguiev, Katia Sergieva, Filip Simeonov, Tsvetelina Todorova, Bozhidar Vladimirov

Affiliation: National Centre of Radiobiology and Radiation Protection, Queen Giovanna University Hospital

Abstract Preview: Purpose: Dosimetry audit is an essential tool enhancing confidence in the accuracy of treatment delivery and in prevention of radiation treatment incidents. Current work depicts how novel nationwide r...

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...

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...

Development and Clinical Validation of Hyperarc Stereotactic Radiosurgery Method for Intraocular Tumors

Authors: Chase Cochran, Damodar Pokhrel, William St Clair

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

Abstract Preview: Purpose: Currently, intraocular disease is primarily treated via COMS-plaques brachytherapy. Various stereotactic approaches via photons/proton beam have also been implemented (CyberKnife/GammaKnife/p...

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...

Developments of a Low-Cost Multi-Target Winston-Lutz Phantom and Software for SRS Linac Machines

Authors: Nellie Brovold, Wenbo Gu, Huan Amanda Liu, Lin Ma

Affiliation: University of Pennsylvania, Mayo Clinic

Abstract Preview: Purpose: To develop a low-cost comprehensive QA phantom and software for single-iso multi-target SRS Linac machines. This phantom can perform 1) Winston-Lutz QA test for on-axis and off-axis targets, ...

Differential Hole-Size Lattice Patterns for Escalating SFRT Dose to Large, Deep-Seated, and Unresectable Masses

Authors: Joshua Misa, Damodar Pokhrel, William St. Clair

Affiliation: University of Kentucky, Department of Radiation Medicine

Abstract Preview: Purpose: Development of a novel spatially fractionated radiotherapy (SFRT) lattice deployment method featuring a large high-dose sphere at the tumor’s center, surrounded by smaller diameter spheres. W...

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....

Dosimetric Accuracy Evaluation of Brainlab Elements 4.0 Treatment Planning System

Authors: Bhuvaneswari Narayanan, Niko Papanikolaou, Daniel L. Saenz

Affiliation: UT Health San Antonio, University of Texas HSC San Antonio

Abstract Preview: Purpose: To evaluate dosimetric accuracy of Brainlab Elements (BLE) 4.0 treatment planning system (TPS) for linac based SRS and Spine SBRT treatment.
Methods: RT Safe cranial and thorax phantoms wi...

Dosimetric Assessment of Multicriteria Optimization for Accelerated Partial Breast Irradiation (APBI)

Authors: Alyssa Gadsby, William J. Godwin, Jennifer L. Harper, 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: Multi-Criteria Optimization (MCO) theoretically allows for increased dose control during optimization. This study is the first to compare standard optimization (SO) and MCO for accelerated pa...

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...

Evaluating Pulse Normalization for Enhanced Ion Chamber Signal Correction in Relative Dosimetry during Beam Scanning

Authors: Alejandro Cuadra, Paulina E. Galavis, Juan Leal, Enrique Lozano, Franklin Reggio, Gabriel Zelada

Affiliation: Clínica Iram, Clinica Alemana, Hospital Clínico de Magallanes, E&G Medical Systems Ltda, NYU Langone Health

Abstract Preview: Purpose: To investigate and compare the new method “Pulse Normalization” proposed by Sun Nuclear to correct ion chamber signal for fluctuations in the accelerator output while performing relative dosi...

Evaluating Target Isocenter Accuracy in Off-Isocenter Treatments Using an Extended Winston-Lutz Test

Authors: Maria de la Luz De Ornelas, Yunze Yang

Affiliation: University of Miami

Abstract Preview: Purpose:
An extended Winston-Lutz test (EWL), also known as off-axis Winston-Lutz, was performed to assess the linear accelerator’s (linac) deviations at isocenter and five off-iso targets. The imp...

Evaluation of the Latest Plastic Scintillating Detector System with Probe Sizes of 0.5 × 0.5 mm2 and 1.0 × 1.0 mm2 for Small Field Dosimetry

Authors: Milad BaradaranGhahfarokhi, Ashley Elizabeth Bonner, James R. Burns, Annie Cooney, George X. Ding, Kenneth L. Homann, Guozhen Luo

Affiliation: Corewell Health William Beaumont University Hospital, Vanderbilt University Medical Center

Abstract Preview: Purpose: The goal of this study was to evaluate the performance of a new plastic scintillating detector (PSD) system with 0.5×0.5 mm2 and 1.0×1.0 mm2 probes (referred to as Medscint0.5 and Medscint1.0...

Feasibility and Consistency of a Quad Wedge with a 2D Detector Array for Routine Quality Assurance on a MR-Linac

Authors: Grace Hutchinson, Daniel E. Hyer, Samuel D. Rusu, Blake R. Smith, Joel J. St-Aubin

Affiliation: Iowa Health Care, University of Iowa

Abstract Preview: Purpose: To assess the feasibility and consistency of the Sun Nuclear Corporation (SNC) MR conditional Quad Wedge, as an accessory to the IC Profiler-MR, and to evaluate beam output and energy in the ...

Free Radical Irradiation Emergent (FIRE) MRI: Real-Time MR-Based Quantification of Radiation-Produced Free Radical Generation on a Clinical MR-Linac

Authors: Claire Keun Sun Park, Atchar Sudhyadhom, Veena Venkatachalam, Noah Warner

Affiliation: Harvard–MIT Program in Health Sciences and Technology, Massachusetts Institute of Technology, 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

Abstract Preview: Purpose: Modern radiotherapy achieves sub-millimeter spatial accuracy but fails to account for patient- and spatially-specific variations in biological response. Free radical generation (FRG), particu...

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...

Impact of IMRT Beam Scatter and Electronic Noise on Real-Time Kv and Fluoroscopy Image Quality

Authors: Wei Luo, Cameron Thayer-Freeman, Yifeng Zhao

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

Abstract Preview: Purpose: Real-time Kilovoltage (kV) imaging has emerged as a powerful clinical aid, providing high-precision localization of moving targets during treatment. However, the Megavoltage (MV) treatment be...

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. ...

Impact of Lung Density on Plan Quality and Delivery Parameters in Lung Stereotactic Body Radiation Therapy (SBRT) Plans

Authors: David Chighvinadze, Indra J. Das, Jeremy D. Donaghue, Kevin Stephans, Gregory Videtic, Sugandima Weragoda, Ping Xia

Affiliation: Cleveland Clinic, Cleveland Clinic Sandusky, Northwestern Memorial Hospital, Northwestern University Feinberg School of Medicine, Cleveland Clinic Fairview

Abstract Preview: Purpose:: Evaluate the impact of lung density variations on plan quality and delivery parameters in lung SBRT Plans.
Methods: For a hypothetical case with a real patient anatomy, three GTVs with vo...

Impact of Photon Beam Energy and Symmetry on the Radial Profile Correction Factor for FFF Beams

Authors: Wesley S. Culberson, Larry A. DeWerd, Ahtesham Ullah Khan, Zachary James Welchel

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

Abstract Preview: Purpose: Flattening filter free (FFF) linac beams exhibit a centrally peaked beam profile due to the forward-directed bremsstrahlung production from MeV electrons, leading to volume averaging effects ...

Impact of Source-to-Imager Distance on Patient-Specific Quality Assurance Using Epid

Authors: Hajee Reyaz Ali Sahib, Sangeeta Hazarika, Muthukumaran Manavalan, Jaswin Raj, Daya Nand Sharma, Seema Sharma, Subramani Vellaiyan

Affiliation: AIIMS NCI Jhajjar, PTW North America Corporation, All India Institute of Medical Sciences

Abstract Preview: Purpose:
Purpose is to investigate the effect of extended source-to-imager distances (SID) on the resolution of VMAT patient-specific quality assurance (PSQA) in portal dosimetry (PD).
Methods:<...

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...

LD-V1 Film Characterization for MV Beam Quality

Authors: Ruiming Chen Edmondson, Darwin Abraham Garcia, James A. Kavanaugh, Joseph John Lucido

Affiliation: Mayo Clinic

Abstract Preview: Purpose: Characterize the dose response and reproducibility of a low-dose film for 6 MV photon beam and assess the film’s energy dependence between kV and MV energies.
Methods: A single 8’x10’ LD-V...

Low-Cost Image Quality Assurance Phantom Customization Via Additive Manufacturing

Authors: Sarah E. Holler, Daniel Johnson

Affiliation: Department of Radiation Oncology, University of Kansas Medical Center

Abstract Preview: Purpose: As the technological availability of modern clinical infrastructure increases in resource-restricted regions of the world, the needs to maintain quality standards of practice need not be hamp...

Patient-Specific Quality Assurance in SBRT Treatments Using 3D Polymer Gel Dosimetry

Authors: Esteban Arzaga-Barajas, Paola Jazmin Guadarrama Huerta, Jose Alejandro Jimenez, Guerda Massillon-JL, Maria Adela Poitevin-Chacón, Alejandro Rodriguez-Laguna

Affiliation: UNAM, Medica Sur

Abstract Preview: Purpose: To perform patient-specific quality assurance (PSQA) tests for four SBRT treatments of patients diagnosed with vertebral, ilium, pelvic lymph node and lung tumors.
Methods: MAGIC gel consi...

Presenting a Novel Treatment Scheme for Debulking Unresectable Large Tumors: Feasibility, Safety and Patient Reported Early Clinical Outcomes of SBRT Immediately Post-Spatially Fractionated Radiotherapy Delivery

Authors: James Knight II, Joshua Misa, Damodar Pokhrel, William St Clair, Eddy S Yang

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

Abstract Preview: Purpose: Highly-heterogenous sieve-like dose distribution via SFRT to large/bulky tumors (≥6 cm) could enhance tumor cell-death via both direct/indirect cell-kill mechanisms. Adding highly-conformal S...

Remote Evaluation of Flash Beamlines for Electron, Proton, and MV Photons

Authors: Alexander Baikalov, Luke Connell, Nolan M. Esplen, Michele M. Kim, Stephen F. Kry, Emil Schueler, Hayden Scott, Ryan Sun, Paige A. Taylor, Uwe Titt

Affiliation: The University of Texas MD Anderson Cancer Center, University of Pennsylvania, UT MD Anderson Cancer Center, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center

Abstract Preview: Purpose: to develop an affordable, portable device for accurately measuring FLASH dose rates from protons, electrons, and photons. 4 detectors were utilized to measure the temporal structure of proton...

Stereotactic Body Radiosurgery for Refractory Ventricular Tachycardia: Presenting Efficient Clinic Workflow, Dosimetric Analysis and Patients Reported Clinical Results

Authors: Karam Ayoub, Aaron B Hesselson, Ronald C McGarry, Joshua Misa, Damodar Pokhrel

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

Abstract Preview: Purpose: Noninvasive stereotactic body radiosurgery (SBRS) is emerging treatment option for advanced heart failure patients with refractory-ventricular tachycardia (rVT) who experienced recurrent impl...

Treatment Machine Matching for ELM in Eclipse v18.0 By Adjusting Physical Leaf Gap

Authors: Quyen Duong, Si Young Jang, Soyoung Lee, Samuel Ming Ho Luk

Affiliation: Boston University, Department of Radiation Oncology, University of Vermont Medical Center, Boston Medical Center

Abstract Preview: Purpose: To investigate the clinical impact of physical MLC gaps changes with Millennium 120 MLC on Enhanced Leaf Modeling (ELM) and patient plans, and to establish a new MLC model in Eclipse v18.0 on...

Tumor Dose Escalation for Recurrent Head and Neck SRT Via a Hyperarc-Based Rapidplan Model

Authors: Shane McCarthy, Damodar Pokhrel, William St. Clair, Eddy S Yang

Affiliation: University of Kentucky, Department of Radiation Medicine

Abstract Preview: Purpose: Demonstrating the feasibility of dose escalation for stereotactic recurrent head and neck (RHN) cancers through the deployment of a Hyper-Arc Based RapidPlan (HARP) model through an Eclipse S...

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...

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...