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Results for "density effect": 27 found

A Realistic Computer Simulation Study Assessing How Beam Hardening Affects the Accuracy of CT Lung Attenuation Values

Authors: Zijia Guo, Michael F. McNitt-Gray, Frederic Noo, Karl Stierstorfer

Affiliation: Siemens Healthineers, University of Utah, David Geffen School of Medicine at UCLA

Abstract Preview: Purpose: Accurately assessing lung parenchyma health is critically important in the management of patients with chronic obstructive pulmonary disease. CT attenuation values are valuable for this purpo...

Advancing Thoracic Synthetic CT Images with Enhanced Cyclegan for Adaptive Radiotherapy Applications

Authors: Silambarasan Anbumani, Nicolette O'Connell, Eenas A. Omari, Amanda Pan, Eric S. Paulson, Lindsay Puckett, Monica E. Shukla, Dan Thill, Jiaofeng Xu

Affiliation: Elekta Inc, Elekta Limited, Linac House, Department of Radiation Oncology, Medical College of Wisconsin

Abstract Preview: Purpose: Accurate electron density information from on-board imaging is essential for direct dose calculations in adaptive radiotherapy (ART). This study evaluates a deep learning model for thoracic s...

Assessment of the Dosimetric Characteristics of Brass Mesh Bolus in Electron Radiation Therapy

Authors: Hungcheng Hank Chen, Laura A. Doyle, Helena Frisbie-Firsching, Amy S. Harrison, Jackson D Reeves, Lindsay B Romak, Jon Strasser

Affiliation: Christiana Care

Abstract Preview: Purpose: Brass mesh bolus (BMB) is a high-density woven metal mesh which is an excellent alternative to tissue equivalent bolus in photon beams, offering improved surface conformality. Unlike utilizat...

Comparative Study between Sparse Primary Sampling Grid Scatter Correction and Low-Count Monte Carlo-Based Scatter Reduction with 3-D Richardson-Lucy Denoising

Authors: Alan Rui Li, Qihui Lyu, Dan Ruan, Ke Sheng

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

Abstract Preview: Purpose:
The Sparse Primary Sampling (SPS) grid was shown in a previous computational study to improve image quality by correcting scatter-induced effects and artifacts in Cone-beam Computed Tomogr...

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 ...

Design and Use of a Modified Commercial Phantom for Gamma Knife End-to-End Testing

Authors: Edward A. Opalko, Matthew B. Podgorsak, Dheerendra Prasad

Affiliation: Roswell Park Comprehensive Cancer Center

Abstract Preview: Purpose: To design a 3D printed insert for Varian’s SRS Head Phantom that allows for multi-planar film dosimetry and to evaluate its ability in end-to-end testing for Gamma Knife treatments.
Method...

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...

Developing 3D-Printed Synthetic Vertebrae with Realistic Surgical Haptic Feedback and Biomechanical Properties

Authors: Chloe Duncan, Andrew Kanawati, Peter Malek, Tess Reynolds

Affiliation: University of Sydney, Westmead Hospital, Image X Institute, Faculty of Medicine and Health, The University of Sydney

Abstract Preview: Purpose: Pedicle screw fixation, a standard spinal surgery procedure, has high misplacement rates (~40%) which decrease with surgeon experience. However, opportunities for surgical rehearsal, training...

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 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...

Dosimetry for Low Energy Electrons and Their Potential Use in Radiotherapy

Authors: Christoph Bert, Leon Brückner, Luitpold Distel, Julian Freier, Peter Hommelhoff, Bastian Löhrl

Affiliation: Department of Radiation Oncology, Uniklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Department Physik, Friedrich-Alexander Universität Erlangen-Nürnberg

Abstract Preview: Purpose: Low energy electron (LEE) bunches in the kilo electronvolt (keV) range are thought to have a high relative biological effectiveness (RBE). To investigate this, it is necessary to establish re...

Establishing a Protocol for Quality Assessment of Ultrasound Shear Wave Elastography (SWE) and Application to a Musculoskeletal (MSK) Task

Authors: Kevin M Brom, Jaydev K. Dave, Chunming Gu, Nicholas J. Hangiandreou, Zaiyang Long, Donald J Tradup

Affiliation: Mayo Clinic

Abstract Preview: Purpose: Ultrasound scanner onboard quality checks for shear wave elastography (SWE) rely on operator judgement and are insufficient. This study aims to establish a protocol for quality assessment and...

FMEA for Direct to Unit Adaptive Radiotherapy

Authors: Haleem Azmy, Robbie Beckert, Farnoush Forghani, Dean Hobbis, Dan Hong, Hyun Kim, Eric Laugeman, Silpa Raju-Salicki, Domenic Sievert

Affiliation: Washington University in St. Louis School of Medicine, WashU Medicine, Washington University School of Medicine, Department of Radiation Oncology, Washington University School of Medicine in St. Louis, Washington University School of Medicine, Wash U Medicine, Washington University in St. Louis

Abstract Preview: Purpose: A novel radiation therapy (RT) workflow has recently emerged with the advent of online adaptive RT systems, direct-to-unit (DTU). DTU utilizes online adaptive platforms (MR and CT based) to o...

Geant4-DNA Simulation of Human Breast Cancer Cells Line MCF7 Irradiation with 213bi As Targeted Radionuclides

Authors: Hamid Abdollahi Nasehabad, Mehrangiz Amiri, Mohammad Reza Deevband, Faraz Kalantari, Milad Peer-Firozjaei, Ali Shabestani Monfared, Ehsan Tajikmansoury

Affiliation: Biomedical Engineering and Medical Physics Department, School of Medicine, Shahid Beheshti University of Medical Sciences, Department of Radiology, University of British Columbia, Department of Radiation Oncology, University of Arkansas for Medical Sciences (UAMS), Department of Radiobiology and Medical Physics, Babol University of Medical Sciences, 1. Department of Radiobiology and Medical Physics, Babol University of Medical Sciences, Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine

Abstract Preview: Purpose:
Targeted radionuclide therapy (TRNT) with 213Bi- labeled radiopharmaceuticals is a promising approach in targeted alpha and beta therapy for cancer. This study aims to assess double-strand...

Hydrated Electron Yield Under Electron Irradiation at Ultra-High Dose Rates with Varying Physical Beam Parameters

Authors: Xu Cao, Wesley S. Culberson, Aubrey Parks, Brian W Pogue, Matthew Reed, William Scott Thomas

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

Abstract Preview: Purpose: Under Ultra-High Dose Rate (UHDR) irradiation, radical-radical interactions are likely enhanced due higher density production in time and space and this alters the cascade of reactions that s...

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 Nanoscale TEM-Based and Simplified 3D Modeling Approaches on Monte Carlo Studies of Radiosensitization Effects in Gnp-Laden Cells

Authors: Sang Hyun Cho, Sandun Y. Jayarathna, Amrit Kaphle

Affiliation: The University of Texas MD Anderson Cancer Center

Abstract Preview: Purpose: To assess the effectiveness of various nanoscale models of gold nanoparticle (GNP)-laden cells for Monte Carlo (MC) studies of GNP-mediated radiation dose enhancement/DNA damage.

Metho...

Impact of Serial Passage on Radiation Response and Angiogenic Activity in Head and Neck Cancer Patient-Derived Xenografts

Authors: Liliana Berube, Randall J Kimple, Kwangok P Nickel, Hannah Sondreal

Affiliation: UW Madison

Abstract Preview: Purpose: The fidelity of patient-derived xenografts (PDXs) is crucial for their application in translational research, as it ensures that these models accurately retain the properties of the original ...

Improvements from Monte Carlo Simulations over Pencil Beam Algorithms for Normal Tissue Dose Reconstruction in Proton Therapy Patients

Authors: Amy Berrington de Gonzalez, Keith T Griffin, Jae Won Jung, Cari M Kitahara, Choonik Lee, Choonsik Lee, Aimee L McNamara, Matthew Mille, Harald Paganetti, Sergio Morato Rafet, Jan PO Schuemann, Jungwook Shin, Torunn I Yock

Affiliation: University of Michigan, East Carolina University, Massachusetts General Hospital, National Cancer Institute, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Massachusetts General Hospital and Harvard Medical School, Institute of Cancer Research

Abstract Preview: Purpose: Radiotherapy dose reconstruction enables retrospective epidemiological studies that connect late health effects to the organ-absorbed radiation doses received during treatment. Though clinica...

Preliminary Evaluation of Ultrasound-Derived Fat Fraction Reliability in a Pediatric Cohort

Authors: Lizbeth Ayala-Dominguez, Aaron L Carrel, Diego Hernando, Gabrielle L Hoffmann, Amber Possell, Ivan M. Rosado-Mendez, Jiayi Tang, Andrew Wentland

Affiliation: Department of Pediatrics, University of Wisconsin-Madison, Department of Radiology, University of Wisconsin-Madison, Department of Medical Physics, University of Wisconsin-Madison, Departments of Medical Physics and Radiology, University of Wisconsin-Madison

Abstract Preview: Purpose: Metabolic dysfunction-associated steatotic liver disease (MAFLD) is the leading cause of chronic liver disease in children. While biopsy remains the diagnostic standard, non-invasive imaging ...

Quantitative Analysis of Long-Term Optical Density Variations of Irradiated and Un-Irradiated EBT3 Films

Authors: Rick Holly, Sumudu Katugampola

Affiliation: Gesinger Medical Center, Geisinger Medical Center

Abstract Preview: Purpose:
To quantitatively analyze long term variations in optical density of un-irradiated and irradiated EBT3 radio-chromic films and their effects on dose calibration curves in a clinical settin...

Radiochemical Monte Carlo Model to Investigate the Oxygen Impacts on Radical Yields Under Proton Flash Irradiation

Authors: Yao Hao, Yuting Peng, Francisco Javier Reynoso, Tianyu Zhao, Xiandong Zhao

Affiliation: Varian, University of South Florida, Washington University School of Medicine, Washington University School of Medicine, Department of Radiation Oncology

Abstract Preview: Purpose: Ultra-high dose-rate (FLASH) dose rate (> 40 Gy/s) may result in a radio-protective effect in healthy tissue compared with conventional dose rate (CDR). This effect has been observed in vivo ...

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 Fermi Density Effect: Review and Discussion about Applicability on Stopping Powers and Cross Sections

Authors: Michael Dingfelder

Affiliation: East Carolina University

Abstract Preview: Purpose:
To study and accurately evaluate the influence of the Fermi Density effect on stopping powers and cross sections of charged particles in liquid water used in Monte Carlo radiation transpor...

Tracking Deposited Nanoparticle Cluster Sizes in Inhalation Based Nanoparticle-Enhanced Radiotherapy

Authors: Victoria Susan Ainsworth, Wilfred F. Ngwa, Erno Sajo

Affiliation: University of Massachusetts Lowell, Johns Hopkins University

Abstract Preview: Purpose: In nanoparticle-enhanced radiotherapy, the dose enhancement is function of the particle size. At therapeutic concentrations, the number density of nanoparticles gives rise to a high rate of i...

Tumor Control Probability Estimation of Magnetic Hyperthermia and Radiation Combined Therapy in Prostate Cancer

Authors: John T Barrett, Dan Heo, Chulhaeng Huh, Farshad Mostafaei

Affiliation: Department of Radiation Oncology, Medical College of Georgia, Augusta University, Department of Radiation Oncology, Augusta University

Abstract Preview: Purpose: This study aimed to compare the tumor control probability (TCP) of radiation therapy (RT) and magnetic hyperthermia combined with RT (MHRT) in the human prostate cancer cells based on radiobi...

Using Bayesian Analysis to Quantify the Impact of Clinical and Dosimetric Features for Predicting Swallowing Dysfunction in Oropharyngeal Cancer after Radiotherapy

Authors: Matthew D Blackledge, Christopher M. Nutting, Anju Mohanan Kaimal, Justine Tyler, Konstantinos Zormpas-Petridis

Affiliation: Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Institute of Cancer Research, The Royal Marsden NHS Foundation Trust, The Institute of Cancer Research

Abstract Preview: Purpose: Swallowing dysfunction (dysphagia) is a common side effect of radiotherapy for oropharyngeal cancer, significantly affecting patient's quality of life. This study aims to investigate the rela...