Ultrahypofractionation and Simultaneous Integrated Boost in Breast Cancer: Early Side Effects Analysis

Abstract

The FAST-Forward study paved the way for ultrahypofractionation (UHF) in breast cancer. We prospectively registered and analyzed our case series receiving UHF + simultaneous integrated boost (SIB) to further reduce the treatment to a total of 5 days. The study aimed to present the 6-month early side effects results of the first patients treated with this scheme in 16 radiation oncology centers in Spain. A total of 242 breast cancer patients received adjuvant radiation therapy between April and December 2020. The median age was 61 years (interquartile range, 53-70). All patients underwent breast-conserving surgery. Chemotherapy (QT) was administered to 27.7%, and endocrine therapy to 85.1%. A SIB of 29 Gy was applied to 60.7% of the patients, while 39.3% did not have a boost indication. Breast radiation therapy (RT) with SIB to the tumor bed and regional node irradiation was done in 5.4 % of patients.