Does an integrated boost increase acute toxicity in prone hypofractionated breast irradiation? A randomized controlled trial.

BACKGROUND AND PURPOSE

The safety of a simultaneous integrated boost (SIB) in combination with prone hypofractionated whole-breast irradiation (WBI) was investigated.

MATERIALS AND METHODS

167 patients were randomized between WBI with a sequential boost (SeB) or SIB. All patients were treated in prone position to 40.05Gy in 15 fractions to the whole breast. In the control arm, a SeB of 10Gy in 4 fractions (negative surgical margins) or 14.88Gy in 6 fractions (transsection) was prescribed. In the experimental arm a SIB of 46.8 or 49.95Gy (negative and positive surgical margins, respectively) was prescribed.

RESULTS

Patient age was the only significantly different parameter between treatment arms with patients in the SIB arm being slightly older. In both arms, 6/83 patients developed moist desquamation. Grade 2/3 dermatitis was significantly more frequent in the SeB arm (38/83vs 24/83 patients, p=0.037). In the SIB and SeB arm, respectively, 36 patients (43%) and 51 patients (61%) developed pruritus (p=0.015). The incidence of oedema was lower in the SIB arm (59vs 68 patients), but not statistically significant (p=0.071).

CONCLUSIONS

The primary endpoint, moist desquamation, was not significantly different between treatment arms.