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Title: Dosimetric characteristics of a newly designed grid block for megavoltage photon radiation and its therapeutic advantage using a linear quadratic model

Abstract

Grid radiation therapy with megavoltage x-ray beam has been proven to be an effective technique for management of large, bulky malignant tumors. The clinical advantage of GRID therapy, combined with conventional radiation therapy, has been demonstrated using a prototype GRID block [Mohiuddin, Curtis, Grizos, and Komarnicky, Cancer 66, 114-118 (1990)]. Recently, a new GRID block design with improved dosimetric properties has become commercially available from Radiation Product Design, Inc. (Albertive, MN). This GRID collimator consists of an array of focused apertures in a cerrobend block arranged in a hexagonal pattern having a circular cross-section with a diameter and center-to-center spacing of 14.3 and 21.1 mm, respectively, in the plane of isocenter. In this project, dosimetric characteristics of the newly redesigned GRID block have been investigated for a Varian 21EX linear accelerator (Varian Associates, Palo Alto, CA). These determinations were performed using radiographic films, thermoluminescent dosimeters in Solid Water trade mark sign phantom materials, and an ionization chamber in water. The output factor, percentage depth dose, beam profiles, and isodose distributions of the GRID radiation as a function of field size and beam energy have been measured using both 6 and 18 MV x-ray beams. In addition, the therapeutic advantage obtainedmore » from this treatment modality with the new GRID block design for a high, single fraction of dose has been calculated using the linear quadratic model with {alpha}/{beta} ratios for typical tumor and normal cells. These biological characteristics of the new GRID block design will also be presented.« less

Authors:
; ; ; ; ; ;  [1]
  1. University of Kentucky Chandler Medical Center, Department of Radiation Medicine, Lexington, Kentucky 40536-0084 (United States)
Publication Date:
OSTI Identifier:
20853436
Resource Type:
Journal Article
Journal Name:
Medical Physics
Additional Journal Information:
Journal Volume: 33; Journal Issue: 9; Other Information: DOI: 10.1118/1.2241998; (c) 2006 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-2405
Country of Publication:
United States
Language:
English
Subject:
61 RADIATION PROTECTION AND DOSIMETRY; BEAM PROFILES; BIOPHYSICS; COLLIMATORS; CROSS SECTIONS; DEPTH DOSE DISTRIBUTIONS; DESIGN; IONIZATION CHAMBERS; LINEAR ACCELERATORS; NEOPLASMS; PHANTOMS; PHOTONS; RADIOTHERAPY; THERMOLUMINESCENT DOSEMETERS; X RADIATION

Citation Formats

Meigooni, Ali S, Kai, Dou, Meigooni, Navid J, Gnaster, Michael, Awan, Shahid, Dini, Sharifeh, and Johnson, Ellis L. Dosimetric characteristics of a newly designed grid block for megavoltage photon radiation and its therapeutic advantage using a linear quadratic model. United States: N. p., 2006. Web. doi:10.1118/1.2241998.
Meigooni, Ali S, Kai, Dou, Meigooni, Navid J, Gnaster, Michael, Awan, Shahid, Dini, Sharifeh, & Johnson, Ellis L. Dosimetric characteristics of a newly designed grid block for megavoltage photon radiation and its therapeutic advantage using a linear quadratic model. United States. https://doi.org/10.1118/1.2241998
Meigooni, Ali S, Kai, Dou, Meigooni, Navid J, Gnaster, Michael, Awan, Shahid, Dini, Sharifeh, and Johnson, Ellis L. 2006. "Dosimetric characteristics of a newly designed grid block for megavoltage photon radiation and its therapeutic advantage using a linear quadratic model". United States. https://doi.org/10.1118/1.2241998.
@article{osti_20853436,
title = {Dosimetric characteristics of a newly designed grid block for megavoltage photon radiation and its therapeutic advantage using a linear quadratic model},
author = {Meigooni, Ali S and Kai, Dou and Meigooni, Navid J and Gnaster, Michael and Awan, Shahid and Dini, Sharifeh and Johnson, Ellis L},
abstractNote = {Grid radiation therapy with megavoltage x-ray beam has been proven to be an effective technique for management of large, bulky malignant tumors. The clinical advantage of GRID therapy, combined with conventional radiation therapy, has been demonstrated using a prototype GRID block [Mohiuddin, Curtis, Grizos, and Komarnicky, Cancer 66, 114-118 (1990)]. Recently, a new GRID block design with improved dosimetric properties has become commercially available from Radiation Product Design, Inc. (Albertive, MN). This GRID collimator consists of an array of focused apertures in a cerrobend block arranged in a hexagonal pattern having a circular cross-section with a diameter and center-to-center spacing of 14.3 and 21.1 mm, respectively, in the plane of isocenter. In this project, dosimetric characteristics of the newly redesigned GRID block have been investigated for a Varian 21EX linear accelerator (Varian Associates, Palo Alto, CA). These determinations were performed using radiographic films, thermoluminescent dosimeters in Solid Water trade mark sign phantom materials, and an ionization chamber in water. The output factor, percentage depth dose, beam profiles, and isodose distributions of the GRID radiation as a function of field size and beam energy have been measured using both 6 and 18 MV x-ray beams. In addition, the therapeutic advantage obtained from this treatment modality with the new GRID block design for a high, single fraction of dose has been calculated using the linear quadratic model with {alpha}/{beta} ratios for typical tumor and normal cells. These biological characteristics of the new GRID block design will also be presented.},
doi = {10.1118/1.2241998},
url = {https://www.osti.gov/biblio/20853436}, journal = {Medical Physics},
issn = {0094-2405},
number = 9,
volume = 33,
place = {United States},
year = {Fri Sep 15 00:00:00 EDT 2006},
month = {Fri Sep 15 00:00:00 EDT 2006}
}