Download or read book A Novel Dosimetric Protocol for High Energy Photon Radiotherapy Beams in Norway Using Radiochromic Film written by Alexander Mauring and published by . This book was released on 2010 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Protocol for Clinical Reference Dosimetry of High Energy Photon and Electron Beams written by Peter R. Almond and published by . This book was released on 2000-01-01 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Intravascular Brachytherapy Physics written by AAPM Radiation Therapy Committee. Task Group 60 and published by . This book was released on 1999 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dosimetry of High energy Photon Beams Based on Standards of Absorbed Dose to Water written by and published by . This book was released on 2001 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Protocols for the Dosimetry of High energy Photon and Electron Beams written by European Society for Therapeutic Radiology and Oncology and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Code of Practice for the Dosimetry of High energy Photon Beams written by B. J. Mijnheer and published by . This book was released on 1986 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radiochromic Film Dosimetry System for Clinical CTDl Measurements written by Chrystian Quintero Mateus and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The scope of this project was to measure dose profiles using Gafchromic® XR-QA2 films when clinical protocols were used to scan a PMMA phantom with CT scanners and kV Cone Beam Computed Tomography (CBCT) systems integrated into linear accelerators. Estimated volume CT dose index CTDIvol values based on measured dose profiles were compared to tabulated data in order to assess the reproducibility and accuracy of this method in clinical use. The feasibility study of the radiochromic film-based dosimetry system included an evaluation of the film response as a function of the effective photon energy over the energy range used in radiology and estimation of the precision of the CTDI measurements during helical (on CT scanner) and cone beam CT acquisitions (on linear accelerator).Energy dependence of the Gafchromic® XR-QA2 film was tested over the imaging energy range covered by multiple commercially available CT scanners and on-board imaging (OBI) devices on linear accelerators. A General Electric LightSpeed® LS 16 radiotherapy simulator was used for this purpose. The effective energy of multiple beams was estimated via HVL measurements, and the device output was obtained following the AAPM TG-61 protocol. Strips of film were irradiated in air to known air kerma values ([Kair]air) with the x-ray tube of the CT scanner in static mode. The reflectance change of the film prior and after irradiation was assessed using an in-house Matlab code with the TIFF images of the films scanned by an Epson® Expression 10000XL flatbed document scanner. Calibration curves for each beam quality were created to model the response of the film in the [Kair]air range up to100 mGy. Pixel values were read out after applying a low filter kernel to the extracted red channel from the images. Responses of the film for the same dose values were then compared.Film strips were sandwiched between PMMA rods cut in half and placed into both the peripheral and central holes of a CTDI phantom. Three sets of films were irradiated under the same scanning parameters, and the procedure was repeated for several clinical scanning protocols on each imaging device. The change in the reflectance of the film was converted into [K_air ]_air using calibration curves and subsequently converted into dose to water (D_w) using mass energy absorption coefficients. Finally, D_w profiles were averaged to calculate CTDIvol values. Averaged CTDIvol values from three measurements (CTDIvolIXR-QA2) were compared to the corresponding tabulated CTDIvol values provided by the manufacturer (CTDIvolItabulated). Dispersion of the data was used to assess reproducibility of the dosimetric system. Measured to tabulated CTDI values ratio was used to assess accuracy.The relative variation of the film response was determined to be inversely proportional to the absorbed dose. The maximum absolute variation was observed at 30 mGy over the studied effective energy range. The observed variation diminishes up to 50 % as dose decreases to 5 mGy, and up to 75 % as dose increases to 100 mGy. The reproducibility of CTDIvolIXR-QA2 values was similar for CT simulators and CBCT devices. A linear correlation between I- CTDIvolIXR-QA2 and CTDIvolItabulated values was found for CT simulators and CBCT devices with acceptable correlation factors. CTDIvolIXR-QA2 values were on constantly lower than CTDIvolItabulated values for CT simulators and higher for CBCT devices. Film dosimetry using Gafchromic® XR-QA2 film proved to be reproducible regardless of the analyzed imaging protocol, but its clinical use may result in relatively high systematic error in dose measurements if a single calibration curve is used. We found relatively large discrepancy between measured and tabulated CTDIvol values for various protocols and imaging systems. Our findings strongly support the trend towards replacing the CTDI value with measurement of equilibrium dose in the center of a cylindrical phantom as suggested by TG-111." --
Download or read book Microdosimetric Determination of Radiation Quality in Very High Energy Photon Beams for Conformal Radiotherapy written by and published by . This book was released on 1997 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dosimetry of High energy Photon Beams Based on Standards of Absorbe Dose to Water written by and published by . This book was released on 2001 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Absorbed Dose Determination in External Beam Radiotherapy written by International Atomic Energy Agency and published by . This book was released on 2000 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Code of Practice, which has also been endorsed by WHO, PAHO and ESTRO, fulfils the need for a systematic and internationally unified approach to the calibration of ionization chambers in terms of absorbed dose to water and to the use of these detectors in determining the absorbed dose to water for the radiation beams used in radiotherapy. It provides a methodology for the determination of absorbed dose to water in the low, medium and high energy photon beams, electron beams, proton beams and heavy ion beams used for external radiation therapy.
Download or read book Cherenkov Emission based In water Photon and Electron Beam Dosimetry written by Yana Zlateva and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "External beam radiotherapy (EBRT) with photon and electron beams, generated by medical linear accelerators (linacs) is a mainstay cancer treatment modality. EBRT is prescribed in terms of radiation absorbed dose, defined as the energy deposited in the patient per unit mass. The measurement of absorbed dose, termed dosimetry, is critical for ensuring that a sufficient dose is delivered to the patient while minimizing the dose to surrounding healthy tissues. This includes linac beam calibration and commissioning via reference and relative dosimetry. Reference dosimetry measures absolute dose, whereas relative dosimetry measures relative dose (e.g., spatial dose distribution). Dosimetry is primarily performed in water, as it is the main constituent of soft tissue, and with the use of radiation dosimeters. Modern EBRT dosimeters are not composed of tissue or water, which leads to necessary material conversion, beam perturbation, and volume averaging.We investigate Cherenkov emission (CE) as a potential solution to these challenges. CE is an anisotropic optical signal generated by high-energy radiation in dielectrics, including water. We first evaluate CE for reference dosimetry of broad beams on beam axis in water, which is done for beam calibration with standard uncertainty (k=1) of ~1. The overall objective of the thesis is to develop a clinically-implementable CE-based dosimetry formalism and to thus motivate and inform future dosimetry system development.First, we proposed a CE-to-dose conversion formalism, designed Monte Carlo (MC) simulation code for the calculation of CE-to-dose conversion data used by the formalism, and validated the code experimentally in a relative sense with a preliminary detector design. The experimental validation demonstrated agreement with the simulations within 1%. In addition, the CE spectrum, angular characteristics, measurement robustness, and background signal contributions were evaluated and appropriate recommendations were made for CE-based dosimetry system and protocol development.Secondly, motivated by the experimental validation, we MC-calculated CE-to-dose conversion data for a clinically representative library of electron beam qualities, investigated beam quality specification (a measurable quantity necessary to select the conversion data specific to the user's beam), and estimated a potentially achievable dosimetric uncertainty budget at a reference depth in water. We demonstrated that a combined standard dosimetric uncertainty (k=1) of the order of 1% could be achievable. This motivates further CE-based dosimetry system development.Finally, we performed an MC charged particle step-size dependence study of the CE-to-dose conversion with both photon and electron beams. The goal of this study was to understand the physics and determine whether corrections to the code and the formalism are warranted. For electron beams, the deviations from terse step control are up to 1%. Therefore, we recommend using the results of this study to augment the uncertainties to electron beam CE-to-dose conversion data or to guide step control in future calculations with the current version of the code. For photon beams, the deviations can be up to 10% depending on the optical detection system configuration. Therefore, we recommend using the results of this study to guide further MC code and formalism development for CE-based photon beam dosimetry.This work demonstrates the feasibility and the clinical viability of CE-based photon and electron beam radiotherapy dosimetry. The results of this thesis motivate and inform CE-based dosimetry system and future protocol development efforts. The next step is MC code and formalism development for CE-based photon beam dosimetry, followed by dosimetry system development. This research could ultimately lead to a 3D, micrometer-resolution, perturbation-free, in-water dosimetry technique that can be used in external beam radiotherapy of cancer"--
Download or read book Dosimetry of High Energy Photon and Electron Beams written by Schweizerische Gesellschaft für Strahlenbiologie und Medizinische Physik and published by . This book was released on 1992 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Implementation of the International Code of Practice on Dosimetry in Radiotherapy TRS 398 written by International Atomic Energy Agency and published by IAEA. This book was released on 2005 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides guidelines to Secondary Standards Dosimetry Laboratories on how to establish a standard of absorbed dose to water in a 60Co gamma ray beam, and provides guidelines on the changes that can be expected when IAEA Technical Reports Series No. 398 (TRS-398) is adopted in a hospital environment.
Download or read book High energy Photon Beam Therapy Dosimetry with Ionisation Chambers written by and published by . This book was released on 2000 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High energy Photons and Electrons written by Simon Kramer and published by . This book was released on 1976 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Practical Guidelines for the Implementation of in Vivo Dosimetry with Diodes in External Radiotherapy with Photon Beams entrance Dose written by and published by . This book was released on 2001 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radiation Oncology Physics written by International Atomic Energy Agency and published by IAEA. This book was released on 2005 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication is aimed at students and teachers involved in teaching programmes in field of medical radiation physics, and it covers the basic medical physics knowledge required in the form of a syllabus for modern radiation oncology. The information will be useful to those preparing for professional certification exams in radiation oncology, medical physics, dosimetry or radiotherapy technology.
