Electron Conformal Radiotherapy for Post-Mastectomy Irradiation: A Bolus-Free, Multi-Energy, Multi-Segmented Field Algorithm
Abstract
Post-mastectomy irradiation is used to eliminate residual viable tumor remaining after mastectomy. It is a technically complex treatment requiring consideration of the primary tumor location, possible risk of internal mammary node involvement, varying chest wall thickness due to surgical defects or body habitus, and risk of damaging normal underlying structures (Perkins 2001). Electron conformal therapy (ECT) is a tool that can be used for treating these patients. Bolus ECT modulates the electron energy incident on the patient by varying the thickness of a bolus placed on the patient surface. Its clinical efficacy has been shown for chest wall treatments (Perkins 2001). As an alternative, segmented-field ECT uses multiple abutted electron fields to attempt to achieve a similar effect. The purpose of this research was to evaluate the feasibility of producing conformal electron dose distributions for post-mastectomy irradiation without customized bolus by using multi-energy, multi-segmented electron fields. The hypothesis was that compared to customized electron bolus radiotherapy for post-mastectomy irradiation, ECT with multi-energy, multi-segmented treatment fields has equivalent target coverage and equivalent (or better) normal tissue sparing and planning target volume (PTV) dose uniformity. The specific aims of the research were to 1) develop an algorithm to generate multi-energy, multi-segmented conformal electron treatment plans, 2) verify that the algorithm can create optimized treatment plans for simple targets, and 3) verify that the algorithm can create optimized treatment plans for previously irradiated post-mastectomy patient cases.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2005
- Accession Number
- ADA437115
Entities
People
- Robert A. Rogers
Organizations
- University of Texas at Austin