Comparison of two radiotherapeutic hypofractionated schedules in the application of tumor bed boost

Aim: Evaluation of related radiation toxicity and efficacy in terms of local control of 2 radiotherapeutic hypofractionated schedules in the application of tumor bed boost by using 2 different planning techniques.

Method: Eighty-one patients with stage I-II disease were retrospectively selected with either concomitant (group A) or sequential (group B) boost for the tumor bed. In group A, 27 patients were treated with a total dose of 46 Gy to the whole breast and 54 Gy to the tumor bed in 20 concomitant fractions. In group B, 54 patients were treated with a total dose of 42.4 Gy in 16 fractions to the whole breast and 53 Gy to the tumor bed by 4 sequential fractions. The boost was administered with multiple photon-beam fields. The median follow-up time was 24 months.

Results: The statistical analysis for the 2 groups of the study showed that skin toxicity was significantly worse in group A (P < .05, Kruskal-Wallis H test). For groups A and B at the completion of radiation therapy, grade 1 skin toxicity was observed in 18/27 patients (66.6%) and 13/54 patients (24.1%), respectively, whereas grade 2/3 was observed in 9/27 patients (33.3%) vs. 5/54 patients (9.3%), respectively (P < .001). One year after irradiation, in group A and in group B, the skin toxicity was of grade 1 in 6/27 patients (22.2%) vs. 2/54 patients (3.7%), respectively (P = .008). Within 2 years, the breast returned to its original form in all patients. No patient showed local disease recurrence.

Conclusions: The accelerated hypofractionated schedules in the application of the tumor bed boost by using the 2 different planning techniques appears to be effective and well tolerated.