Dose Gradient Impact on Biological Equivalent Dose for Accelerated Partial Breast Irradiation using High Dose Rate Interstitial Brachytherapy

Abstract

The NASB PB-39/RTOG 0413 phase III trial compares partial versus whole breast irradiation. Partial breast irradiation (PBI) techniques included external beam radiation therapy (EBRT), interstitial high dose rate brachytherapy (IHDRB) and MammoSite. The delivered doses are currently 38.5 and 34 Gy in 10 fractions over 5 days (10f/5d) for EBRT and IHDRB respectively. The purpose of this study is to investigate whether the two radiation modalities are biologically equivalent.