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Title: SU-F-T-82: Dosimetric Evaluation of a Shield Used for Hemi-Body Skin Electron Irradiation

Abstract

Purpose: We had several mycosis fungoides patients with a limited disease to about half of the skin surface. A custom-made plywood shield was used to protect the non-targeted skin region with our total skin electron irradiation (TSEI) technique. We report a dosimetric evaluation for our “hemi-body” skin electron irradiation technique. Methods: The technique is similar to our clinical total skin electron irradiation (TSEI), performed with a six-pair dual field (Stanford technique) at an extended source-to-skin distance (SSD) of 377 cm, with the addition of a plywood shield placed 50 cm from the patient. The shield is made of three layers of standard 5/8″ thick plywood (total thickness of 4.75 cm) that are clamped securely on an adjustable-height stand. Gafchromic EBT3 films were used in assessing the shield’s transmission factor and the extend of the dose penumbra region. To verify the dose delivered for hemi-body skin radiation in a real patient treatment, in-vivo dosimetry using Gafchromic EBT3 films were performed. Film pieces were taped on the patient skin to measure the dose received during the first two fractions, placed on the forehead and upper body (shielded region); and also at the level of pelvic area, left thigh, and left ankle. Results:more » The shield transmission factor was found to be 10%, and the width of the penumbra (80-to-20% dose fall-off) was about 12 cm. In-vivo dosimetry of a real case confirmed the expected shielded area dose. Conclusion: Hemi-Body skin electron irradiation at an extended SSD is feasible with the addition of a plywood shield at a distance from patient skin. The penumbra dose region and the shield’s transmission factor should be evaluated prior to clinical use. We have treated several hemi-body skin patients with our custom-made plywood shield, the current patient measurements are representative of these for other patients as well.« less

Authors:
;  [1]; ; ;  [1];  [2]
  1. Roswell Park Cancer Institute, Buffalo, NY (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22642330
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Physics; Journal Volume: 43; Journal Issue: 6; Other Information: (c) 2016 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; 62 RADIOLOGY AND NUCLEAR MEDICINE; DOSIMETRY; EVALUATION; IN VIVO; IRRADIATION; PATIENTS; RADIATION DOSES; SHIELDS; SKIN

Citation Formats

Rivers, C, Singh, A, AlDahlawi, I, Wang, I, Podgorsak, M, and State University of New York at Buffalo, Buffalo, NY. SU-F-T-82: Dosimetric Evaluation of a Shield Used for Hemi-Body Skin Electron Irradiation. United States: N. p., 2016. Web. doi:10.1118/1.4956218.
Rivers, C, Singh, A, AlDahlawi, I, Wang, I, Podgorsak, M, & State University of New York at Buffalo, Buffalo, NY. SU-F-T-82: Dosimetric Evaluation of a Shield Used for Hemi-Body Skin Electron Irradiation. United States. doi:10.1118/1.4956218.
Rivers, C, Singh, A, AlDahlawi, I, Wang, I, Podgorsak, M, and State University of New York at Buffalo, Buffalo, NY. 2016. "SU-F-T-82: Dosimetric Evaluation of a Shield Used for Hemi-Body Skin Electron Irradiation". United States. doi:10.1118/1.4956218.
@article{osti_22642330,
title = {SU-F-T-82: Dosimetric Evaluation of a Shield Used for Hemi-Body Skin Electron Irradiation},
author = {Rivers, C and Singh, A and AlDahlawi, I and Wang, I and Podgorsak, M and State University of New York at Buffalo, Buffalo, NY},
abstractNote = {Purpose: We had several mycosis fungoides patients with a limited disease to about half of the skin surface. A custom-made plywood shield was used to protect the non-targeted skin region with our total skin electron irradiation (TSEI) technique. We report a dosimetric evaluation for our “hemi-body” skin electron irradiation technique. Methods: The technique is similar to our clinical total skin electron irradiation (TSEI), performed with a six-pair dual field (Stanford technique) at an extended source-to-skin distance (SSD) of 377 cm, with the addition of a plywood shield placed 50 cm from the patient. The shield is made of three layers of standard 5/8″ thick plywood (total thickness of 4.75 cm) that are clamped securely on an adjustable-height stand. Gafchromic EBT3 films were used in assessing the shield’s transmission factor and the extend of the dose penumbra region. To verify the dose delivered for hemi-body skin radiation in a real patient treatment, in-vivo dosimetry using Gafchromic EBT3 films were performed. Film pieces were taped on the patient skin to measure the dose received during the first two fractions, placed on the forehead and upper body (shielded region); and also at the level of pelvic area, left thigh, and left ankle. Results: The shield transmission factor was found to be 10%, and the width of the penumbra (80-to-20% dose fall-off) was about 12 cm. In-vivo dosimetry of a real case confirmed the expected shielded area dose. Conclusion: Hemi-Body skin electron irradiation at an extended SSD is feasible with the addition of a plywood shield at a distance from patient skin. The penumbra dose region and the shield’s transmission factor should be evaluated prior to clinical use. We have treated several hemi-body skin patients with our custom-made plywood shield, the current patient measurements are representative of these for other patients as well.},
doi = {10.1118/1.4956218},
journal = {Medical Physics},
number = 6,
volume = 43,
place = {United States},
year = 2016,
month = 6
}
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