5-year outcomes of a randomized trial comparing prone and supine whole breast irradiation in large breasted women.

Abstract

INTRODUCTION\nProne position for whole breast irradiation (WBI) results in lower rates of toxicity and reduced ipsilateral mean lung and heart doses. No randomized trials comparing toxicity and cosmesis at 5 years, comparing prone and supine positioning, are available.\n\n\nMETHODS\nIn this phase II open-label trial, one-hunderd patients, with large breast size requiring WBI were randomized between prone and supine position. Physician-assessed toxicity (retraction, fibrosis, edema, telangiectasia, pigmentation changes) was scored yearly, for a total of 5 years, and photographs were taken at 5 years to assess cosmesis. The data was analyzed longitudinally and cross-sectionally.\n\n\nRESULTS\nLongitudinal analysis shows lower grade 2 late toxicity in prone position. The results of at least grade I physician-assessed toxicity at 5 years are similar between respectively supine and prone position for retraction (56% vs 54%), fibrosis outside the tumorbed (33% vs 24%), tumorbed fibrosis (49% vs 46%), edema (11% vs 8%), telangiectasia (8% vs 3%) and breast pain (6% vs 8%), using cross-sectional analysis. However, the risk of pigmentation changes in prone position (0% vs 19%) 5-years after radiotherapy was significantly lower. Cosmesis was good or excellent in 92% and 75% of patients in prone and supine position respectively. 5-year overall survival is 96% in both groups.\n\n\nCONCLUSION\nProne position results in reduced rates of late toxicity.