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Results for "proton density": 33 found

A Dual Energy CT-Guided Intelligent Radiation Therapy Platform

Authors: Jiayi Chen, Manju Liu, Ning Wen, Haoran Zhang, Yibin Zhang

Affiliation: Department of Radiation Oncology, Ruijin Hospital, Department of Radiology, Ruijin Hospital Shanghai Jiaotong University School of Medicine, Duke Kunshan University, Department of Radiation Oncology,Ruijin Hospital, Shanghai Jiao Tong University School of Medicine

Abstract Preview: Purpose: This study introduces a novel Dual Energy CT (DECT)-Guided Intelligent Radiation Therapy (DEIT) platform designed to streamline and optimize the radiotherapy process. The DEIT system combines...

A Retrospective Assessment of Proton Radiation Response in Brain Tumor Patients Using Diffusion-Weighted MR Imaging

Authors: Liu Hong, Wen C. Hsi, Faraz Kalantari, Romy Megahed, Ganesh Narayanasamy, Maida Ranjbar, Pouya Sabouri, Zhong Su

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

Abstract Preview: Purpose: Quantitative apparent diffusion coefficients (ADC) in diffusion-weighted MRI (dMRI) reflect water diffusivity and thus provide tissue cellular density information. Functional diffusion mappin...

Accelerated Proton Density Imaging Via T2-Guided Cyclegan Super-Resolution without Paired Low-Resolution and High-Resolution Data

Authors: Yunxiang Li, Xinlong Zhang, 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

Abstract Preview: Purpose: Acquiring high-resolution (HR) proton density (PD) images is time-consuming, while lower-resolution (LR) PD scans are faster but can lack sufficient details. We propose CycleHR, a T2-contrast...

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...

Automated Decision Workflow Using Fast Monte Carlo Dose Calculations for Daily Adaptive Proton Therapy

Authors: Ergun E. Ahunbay, Abdul Parchur, Eric S. Paulson, Ilaria Rinaldi, Angelo Schiavi, Li Zhao

Affiliation: Sapienza University of Rome, Department of Radiation Oncology (Maastro), GROW School for Oncology, Maastricht University Medical Centre+, Department of Radiation Oncology, Medical College of Wisconsin

Abstract Preview: Purpose: Online adaptive replanning is often necessary in Intensity Modulated Proton Therapy (IMPT) due to the sensitivity of proton dose distributions to daily anatomical changes. A rapid, automated ...

Automated Determination of Deteriorations in Proton Therapy Plan Quality Using Daily Cone Beam CT As a Predictor of Need for Adaptive Replans for Head and Neck Cases

Authors: Matthew J Ferris, Jason K Molitoris

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

Abstract Preview: Purpose: Anatomy changes often happen in head-and-neck (HN) patients treated with proton radiation therapy. These changes can result in deteriorations of target dose coverage and increased dose to org...

CBCT-Based Synthetic CT Imaging for Proton and Photon Dose Monitoring and Adaption in Supine Breast Radiotherapy

Authors: Mark E Artz, Julie Bradley, Hardev Singh Grewal, Perry B. Johnson, Christina Klassen, Raymond Mailhot Vega, Nancy Mendenhall, Jiyeon Park, Emma V. Viviers, Yawei Zhang

Affiliation: UF Health Proton Therapy Institute, University of Florida

Abstract Preview: Purpose: Verification CTs (VFCT) are used in radiotherapy to assess patient dose during treatment. However, they are time-consuming and contribute additional radiation exposure to the patient. This st...

Can Contrast Scans of Dual-Layer Detector Spectral CT be Directly Used for Proton Dose Calculations?

Authors: Wen C. Hsi, Pouya Sabouri, Zhong Su

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

Abstract Preview: Purpose:
Traditional single-energy CT (SECT) contrast scans cannot be used for proton dose calculations due to significantly higher HU caused by iodine. Dual-layer dual-energy CT (DL-DECT) can dire...

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...

Compact Representation of External Beam Photon Phase Space Data Via Implicit Neural Representation Learning

Authors: Serdar Charyyev, Cynthia Fu-Yu Chuang, Veng Jean Heng, Lianli Liu, Lei Xing, Yong Yang

Affiliation: Department of Radiation Oncology, Stanford University

Abstract Preview: Purpose: To replace large finite-size photon phase space files with a compact neural network capable of generating an infinite number of particles.
Methods: Three separate models were developed to ...

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...

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 Comparison of 6X and 10X Flattening Filter-Free Photon Beams on a Truebeam Linac Using the Eclipse TPS

Authors: Carlos E. Cardenas, Udbhav S. Ram, Marcin Wierzbicki

Affiliation: The University of Alabama at Birmingham, University of Alabama at Birmingham, Juravinski Cancer Centre

Abstract Preview: Purpose:
This study aims to systematically evaluate the dosimetric properties and delivery efficiency of 6X-FFF and 10X-FFF beams for lung SBRT on the Varian TrueBeam STx using the Eclipse TPS 16.1...

Evaluation of MR Proton Density Fat Fraction (PDFF) for Bone Marrow Protection in RT

Authors: Li Tong, Chuyan Wang, Zhengkui Wang, Yingli Yang, Jie Zhang

Affiliation: Shanghai United imaging Healthcare Advanced Technology Research Institute, Shanghai United Imaging Healthcare Co., LTD, Department of Radiology, Ruijin Hospital, Institute for Medical Imaging Technology, Ruijin Hospital

Abstract Preview: Purpose:
Pelvic radiotherapy (RT)-induced bone marrow (BM) damage affects patient prognosis by causing hematologic toxicity. However, consensus on BM-sparing (BMS) RT is still lacking, owing to the...

Feasibility of a Bench-Top Pcct Model for Electronic Density Measurements: A Monte Carlo Simulation Study

Authors: Gisell Ruiz Boiset, Paulo ROBERTO Costa, Renan Felix dos Santos, Gustavo Freire Pereira da Silva, Alessandra Tomal

Affiliation: University of São Paulo (USP), Institute of Physics, Universidade Estadual de Campinas. Instituto de Física Gleb Wataghin

Abstract Preview: Purpose: Evaluate the feasibility of a bench-top PCCT using Geant4 Monte Carlo simulations. The study applied the Geant4 framework on determining the electronic density of materials as a function of C...

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 Lönnqvist, 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 München (LMU Munich), Ludwig-Maximilians Universität, Danish Centre for Particle Therapy, Aarhus University Hospital, Department of Medical Physics, Ludwig-Maximilians-Universität (LMU) München, 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...

Impact of Tissue Heterogeneity on Proton LET and RBE Distributions: A Monte Carlo Study

Authors: Xiangli Cui, Wei Han, Jie Li, Lingling Liu

Affiliation: Institute of Health and Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Hefei Cancer Hospital, Chinese Academy of Sciences, Institute of Health and Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences

Abstract Preview: Purpose: To investigate the influence of tissue heterogeneity on proton beam linear energy transfer (LET) and relative biological effectiveness (RBE) using nine RBE models. This study quantifies the i...

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...

In-Vivo Dosimetry in Positron-Guided Radiation Therapy

Authors: Davide Brivio, Erno Sajo, Ryan Williams, Piotr Zygmanski

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

Abstract Preview: Purpose: To develop a non-invasive 3D in-vivo dosimetry tool exploring the relationship between positron annihilations and dose per voxel using Monte Carlo simulation. The Positron Guided Radiation Th...

Knowledge-Based Online Adaptive Proton Stereotactic Ablative Radiotherapy (SABR) for Localized Prostate Cancer Using Gaussian Process Regression

Authors: Hania A. Al-Hallaq, Duncan Henry Bohannon, Chih-Wei Chang, Anees H. Dhabaan, Vishal Dhere, H Scott McGinnis, Pretesh Patel, Sagar Patel, Keyur Shah, Xiaofeng Yang, Jun Zhou

Affiliation: Emory University, Department of Radiation Oncology and Winship Cancer Institute, Emory University

Abstract Preview: Purpose: Two-fraction proton SABR is an attractive alternative to brachytherapy for localized prostate cancer. However, potential interfractional anatomical changes necessitate online adaptation, espe...

Monte Carlo Derived Correction Factors for Ion Chambers Used in the Calibration of Gamma Knife Perfexion Model: Impact of Phantom Materials and Chamber Orientation on Dosimetric Accuracy

Authors: Catherine Coolens, Robert K. Heaton, Lalageh Mirzakhanian, Tasnim Rahman, Jan P. Seuntjens

Affiliation: Princess Margaret Cancer Centre & University of Toronto, McGill University, Princess Margaret Cancer Centre, Princess Margaret Hospital, University of Toronto

Abstract Preview: Purpose: Commissioning of a Gamma Knife® (GK) (Elekta, Sweden) unit requires precise dosimetric reference measurements, particularly for small fields. The IAEA TRS-483/AAPM TG-155 code of practice (20...

Multiparametric and Low-Field MRI for Biomimetic MRI-Readable Gel Dosimeters

Authors: Kaitlyn M Betz, David Dunkerley, Eric Johnson, Kalina V Jordanova, Kathryn E. Keenan, Samuel D Oberdick, Gregory P. Penoncello, Stephen E Russek

Affiliation: Dept of Radiology, Stanford, University of Colorado School of Medicine, NIST, College of Wooster

Abstract Preview: Purpose: Examine use of low-field MRI and multiparametric analysis for 3D MRI-readable biomimetic gel dosimetry. Low-field MRIs are compact, inexpensive, and portable. They could be located within rad...

Non-Planar Narrow-Beam CT: Near Scatter-Free, High-Resolution Breast Imaging at Screening Mammography Doses.

Authors: Peymon Ghazi

Affiliation: MALCOVA Inc.

Abstract Preview: Purpose: To develop a near scatter‐free breast CT imaging system that expands coverage of the posterior breast anatomy and enhances contrast resolution for solid masses and microcalcifications, while ...

Photon Counting CT Method for Accurate Effective Atomic Number and Electron Density Measurement

Authors: Mohammed Alzaabi, Abderaouf Behouch, Nabil Maalej, Aamir Raja, Briya Tariq

Affiliation: Khalifa University

Abstract Preview: Purpose: Spectral Photon Counting CT (SPCCT) has emerged as a transformative technology in CT imaging capable of producing images from distinct energy windows, allowing improved material characterizat...

Photon-Counting CT for Estimation of Quantitative Information for Radiation Therapy Treatment Planning: Assessment of Scanning Conditions and Phantom Sizes

Authors: Carina Gassner, Guyue Hu, Thomas Kröncke, Christopher Kurz, Guillaume Landry, Katharina Niepel, Katia Parodi, Franka Risch, Florian Schwarz

Affiliation: Department of Radiation Oncology, LMU University Hospital, LMU Munich, Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Department of Medical Physics, Ludwig-Maximilians-Universität (LMU) München, Department of Medical Physics, Ludwig-Maximilians-Universität München (LMU Munich)

Abstract Preview: Purpose: To evaluate the performance of a clinical photon-counting CT (PCCT) scanner in terms of proton relative stopping power (RSP) estimation using PCCT data and to compare the impact of different ...

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...

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 ...

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 ...

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...

Universal Range Modulators for Flash Proton Therapy: 3D Printing of Stackable Variable Density Units

Authors: Eric S. Diffenderfer, Lei Dong, Alejandro Garcia, Wenbo Gu, Michele M. Kim, Alexander Lin, Kai Mei, Peter B. Noël, Boon-Keng Kevin Teo, Lingshu Yin, Jennifer Wei Zou

Affiliation: Department of Radiation Oncology, University of Pennsylvania, University of Pennsylvania

Abstract Preview: Purpose: We present a novel 3D-printed range-modulating devices with spatially modulated density for FLASH particle therapy. By varying density distributions, spread-out Bragg peaks(SOBPs) can be gene...

Virtual Monoenergetic Imaging for Radiotherapy: A Single CT Acquisition for Both Target Delineation and Dose Calculation

Authors: Harold Y Hu, Yanle Hu, Shuai Leng, Maryam Sadeghian, Joe Swicklik

Affiliation: Mayo Clinic Arizona, Basis Scottsdale, Mayo Clinic

Abstract Preview: Purpose: Radiotherapy CT simulation often requires two scans: a non-contrast scan for dose calculation and a contrast-enhanced scan for target delineation. Photon-counting-detector (PCD) CT allows the...

Water-Equivalent Thickness Mapping (WET-MAP) – a Potential Alternative to 4D Robust Optimization for Motion Management in Proton Treatment Planning

Authors: Duncan Henry Bohannon, Pretesh Patel, Sibo Tian, Yinan Wang, Xiaofeng Yang, Ahmal Jawad Zafar, Jun Zhou

Affiliation: Emory University, Department of Radiation Oncology and Winship Cancer Institute, Department of Radiation Oncology and Winship Cancer Institute, Emory University

Abstract Preview: Purpose:
4D robust optimization, incorporating additional images (e.g., maximum inhale/exhale phases), is commonly used to account for target motion in proton treatment planning. However, the incre...