skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: SU-E-T-437: Dosimetric Assessment of Brass Mesh Bolus for Postmastectomy Chest Wall Irradiation

Abstract

Purpose: It has been suggested that the use of a brass mesh bolus for chest wall irradiation sufficiently increases surface dose while having little effect on the dose at depth. This work quantified the increase in surface dose when using a brass mesh bolus in postmastectomy chest wall radiotherapy compared to tissue-equivalent bolus and assessed its effect on dose at depth. Methods: Percent depth doses with brass bolus, 5mm tissue-equivalent bolus, and no bolus were determined for a 6 MV photon beam in a solid water phantom using a parallel plate ionization chamber. Gafchromic film was used to determine the surface dose for the same three experimental setups. For comparison to a realistic treatment setup, gafchromic film and OSLDs were used to determine the surface dose over the irradiated area of a 6 MV chest wall plan with tangential beams delivered to a heterogeneous thorax phantom. The plan was generated using a CT of the phantom and delivered using brass mesh bolus, 5mm tissue-equivalent bolus, and no bolus. Results: For the en face beam, the central surface dose increased to 90% of maximum with the tissue-equivalent bolus, but to only 62% of maximum with the brass mesh. Using tangential beamsmore » on the thorax phantom, the surface dose increased from 40–72% to 75–110% of prescribed dose, with the brass mesh, and to 85–109% with the tissue-equivalent bolus. At depths beyond dmax in the plastic water phantom, the dose with and without brass mesh bolus differed by less than 0.5%. Conclusion: A brass mesh may be considered as a substitute for tissue-equivalent bolus to increase the superficial dose of 6 MV chest wall tangent plans. The brass mesh does not significantly change the dose at depth, so a non-bolus plan could be used for bolus and non-bolus treatments.« less

Authors:
; ;  [1]
  1. University of California, San Diego, La Jolla, CA (United States)
Publication Date:
OSTI Identifier:
22369588
Resource Type:
Journal Article
Journal Name:
Medical Physics
Additional Journal Information:
Journal Volume: 41; Journal Issue: 6; Other Information: (c) 2014 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:
60 APPLIED LIFE SCIENCES; ANIMAL TISSUES; CHEST; DEPTH DOSE DISTRIBUTIONS; IONIZATION CHAMBERS; IRRADIATION; PHANTOMS; PHOTON BEAMS; RADIOTHERAPY

Citation Formats

Manger, R, Paxton, A, and Cervino, L. SU-E-T-437: Dosimetric Assessment of Brass Mesh Bolus for Postmastectomy Chest Wall Irradiation. United States: N. p., 2014. Web. doi:10.1118/1.4888770.
Manger, R, Paxton, A, & Cervino, L. SU-E-T-437: Dosimetric Assessment of Brass Mesh Bolus for Postmastectomy Chest Wall Irradiation. United States. https://doi.org/10.1118/1.4888770
Manger, R, Paxton, A, and Cervino, L. 2014. "SU-E-T-437: Dosimetric Assessment of Brass Mesh Bolus for Postmastectomy Chest Wall Irradiation". United States. https://doi.org/10.1118/1.4888770.
@article{osti_22369588,
title = {SU-E-T-437: Dosimetric Assessment of Brass Mesh Bolus for Postmastectomy Chest Wall Irradiation},
author = {Manger, R and Paxton, A and Cervino, L},
abstractNote = {Purpose: It has been suggested that the use of a brass mesh bolus for chest wall irradiation sufficiently increases surface dose while having little effect on the dose at depth. This work quantified the increase in surface dose when using a brass mesh bolus in postmastectomy chest wall radiotherapy compared to tissue-equivalent bolus and assessed its effect on dose at depth. Methods: Percent depth doses with brass bolus, 5mm tissue-equivalent bolus, and no bolus were determined for a 6 MV photon beam in a solid water phantom using a parallel plate ionization chamber. Gafchromic film was used to determine the surface dose for the same three experimental setups. For comparison to a realistic treatment setup, gafchromic film and OSLDs were used to determine the surface dose over the irradiated area of a 6 MV chest wall plan with tangential beams delivered to a heterogeneous thorax phantom. The plan was generated using a CT of the phantom and delivered using brass mesh bolus, 5mm tissue-equivalent bolus, and no bolus. Results: For the en face beam, the central surface dose increased to 90% of maximum with the tissue-equivalent bolus, but to only 62% of maximum with the brass mesh. Using tangential beams on the thorax phantom, the surface dose increased from 40–72% to 75–110% of prescribed dose, with the brass mesh, and to 85–109% with the tissue-equivalent bolus. At depths beyond dmax in the plastic water phantom, the dose with and without brass mesh bolus differed by less than 0.5%. Conclusion: A brass mesh may be considered as a substitute for tissue-equivalent bolus to increase the superficial dose of 6 MV chest wall tangent plans. The brass mesh does not significantly change the dose at depth, so a non-bolus plan could be used for bolus and non-bolus treatments.},
doi = {10.1118/1.4888770},
url = {https://www.osti.gov/biblio/22369588}, journal = {Medical Physics},
issn = {0094-2405},
number = 6,
volume = 41,
place = {United States},
year = {Sun Jun 01 00:00:00 EDT 2014},
month = {Sun Jun 01 00:00:00 EDT 2014}
}