Phase 3 study comparing weekly concomitant boost for breast cancer patients treated with conservative breast surgery with sequential boost

Abstract

Background: Radiation therapy after breast conserving surgery is a standard part of treatment for invasive breast cancer. Based on radiobiological models, it was found that shorter hypofractiontaed radiation schedules had equivalent local control to standard radiation therapy. Radiation boost to the tumor bed was evident to be associated with significant improvement in local control. Methods: This study included 48 female patients with early breast cancer who underwent breast conservative surgery. There were two arm of radiation, hypofractionated radiotherapy with concomitant boost (group A) - hypofractionated radiotherapy with sequential boost (group B). Results: after median follow up 43 months range (21-57). Four year over all survival rate for concomitant boost arm was (91.67%) and sequential boost arm was (87.50%), Four year disease free survival rate for concomitant boost arm was (87.5%) and sequential boost arm was (79.17 %). late skin toxicity, grade 0 was (72.73%) in concomitant boost arm and (54.55%) in sequential boost arm and grade 1 was (9.09%) in concomitant boost arm and (31.82%) in sequential boost arm and grade 2 was (18.19) in concomitant boost arm and (13.55%) in sequential boost arm, grade 3 late lung toxicity was (4.17%) in concomitant boost arm and (12.50%) in sequential boost arm, cardiac toxicity in concomitant boost arm (8.33%) and sequential boost arm (16.67%).The ipsilateral lymphedema after 24 months of follow up G2 (4.55%) in concomitant boost arm G3 (4.55%) in in sequential boost arm. Conclusion: A shortened whole breast irradiation schedule with a weekly concomitant boost may be an alternative option with acceptable toxicity and excellent cosmesis.