Safety of pre- or postoperative accelerated radiotherapy in 5 fractions: A randomized pilot trial

 

by Vakaet Vakaet, Hans Van Hulle, Van de Vijver Koen, Hilderson Ingeborg, Naert Eline, De Neve Wilfried, Jo Vandorpe, An Hendrix, Menekse Göker, Herman Depypere, Glenn Vergauwen, Rudy Van den Broecke, De Visschere Pieter, Braems Geert, Vandecasteele Katrien, Hannelore Denys, Liv Veldeman 

The Breast:  VOLUME 62, P10-15, APRIL 01, 2022

Objective

Neo-adjuvant radiotherapy (NART) for breast cancer has shown promising survival results in retrospective trials. However, there are some obstacles such as a chemotherapy delay, an increased overall treatment time (OTT) and the risk of increasing surgical morbidity. Accelerated radiotherapy (RT) in 5 fractions allows to deliver NART in a very short time span and minimizes the delay of surgery and chemotherapy. This trial investigates this NART schedule for safety, feasibility and OTT.

Material and methods

Twenty patients eligible for neo-adjuvant chemotherapy (NACT) and breast conserving surgery, were randomized between NART before NACT or NACT and postoperative RT. In both arms, RT treatment was given in 5 fractions to the whole breast with a simultaneously integrated boost (SIB) on the tumor(bed). Lymph node irradiation was given concomitantly in case of lymph node involvement. OTT was defined as the time from diagnosis to last surgery in the intervention group, while in the control group the time between diagnosis and last RT-fraction was used. In the intervention group NACT-delay was defined as time between diagnosis and start of chemotherapy.

Results

20 patients were included, and 19 patients completed treatment. OTT was significantly shorter in the intervention group (mean 218 days, range 196–253) compared to the control group (mean 237, range 211–268, p = 0.001). The difference in mean duration from diagnosis to the first treatment was a non-significant 4 days longer (31 vs 27 days, p = 0.28), but the start of NACT after diagnosis was delayed by 21 days (48 vs 27 days, p < 0.001). NART did not result in additional surgery complications.

Conclusion

This pilot trial is the first to report on accelerated NART in 5 fractions with SIB. NART before NACT resulted in a shorter OTT with good safety results.