Establishing the impact of temporary tissue expanders on electron and photon beam dose distributions.

Abstract

PURPOSE:

This study investigates the effects of temporary tissue expanders (TTEs) on the dose distributions in breast cancer radiotherapy treatments under a variety of conditions.

METHODS:

Using EBT2 radiochromic film, both electron and photon beam dose distribution measurements were made for different phantoms, and beam geometries. This was done to establish a more comprehensive understanding of the implant's perturbation effects under a wider variety of conditions.

RESULTS:

The magnetic disk present in a tissue expander causes a dose reduction of approximately 20% in a photon tangent treatment and 56% in electron boost fields immediately downstream of the implant. The effects of the silicon elastomer are also much more apparent in an electron beam than a photon beam.

CONCLUSIONS:

Evidently, each component of the TTE attenuates the radiation beam to different degrees. This study has demonstrated that the accuracy of photon and electron treatments of post-mastectomy patients is influenced by the presence of a tissue expander for various beam orientations. The impact of TTEs on dose distributions establishes the importance of an accurately modelled high-density implant in the treatment planning system for post-mastectomy patients.

• Authors: A Asena, T Kairn, S B Crowe, J V Trapp
• Journal: Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB) (Phys Med) Vol. 31 Issue 3 Pg. 281-5 (May 2015) ISSN: 1724-191X [Electronic] Italy
• PMID: 25693908 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Topics

• Breast Neoplasms (radiotherapy, surgery)
• Electrons (therapeutic use)
• Humans
• Mastectomy
• Photons (therapeutic use)
• Radiation Dosage
• Radiotherapy Dosage
• Tissue Expansion Devices