Ultra Hypo-fractionated Adjuvant Whole Breast Radiation Therapy With Simultaneous Integrated Boost for Early-Stage Breast Cancer (H-ASSIST)

This study evaluates the rates of radiation-specific toxicity, quality of life, and oncologic outcomes for early-stage breast cancer and ductal carcinoma in situ treated with 5-fraction whole breast irradiation (WBI) with a simultaneous integrated tumor bed boost (SIB). SIB refers to the technique tumor bed boost given at the same time as standard radiation therapy. The FAST-Forward trial previously showed that a 1-week course of radiotherapy had similar effects to the traditional 3-week course for early-stage breast cancer after surgery. Given these favorable results, a 5-fraction WBI regimen is appealing for many patients who wish to minimize the number of treatment visits while still reducing their risk of recurrence. Generally, tumor bed boosts further decrease the risk of recurrence, but in the setting of 5-fraction WBI, a more traditional sequential boost technique is utilized.