Background and purpose: To compare the acute toxicity of hypofractionated whole breast radiotherapy (HypoRT) to conventionally fractionated radiotherapy (ConvRT) in large-breasted women with early stage disease.
Materials and methods: Women with breast volume>1500 cm, body mass index>30 kg/m, or separation>25 cm treated with HypoRT or ConvRT from 2005 through 2010 were identified from a prospective database and included in the analysis. Acute toxicity was scored for each treated breast.
Results: Ninety-two patients were treated to 96 breasts. The median body mass index was 33 kg/m and median breast volume was 1932 cm for the ConvRT group compared with 32.4 kg/m and 1825 cm for the HypoRT group. Maximum acute skin toxicity consisted of focal moist desquamation in 26% and 11% of the ConvRT and HypoRT patients, respectively (P=0.002). Breast volume was the only patient factor significantly associated with moist desquamation on multivariable analysis (P=0.01). Among those with a breast volume >2500 cm, focal moist desquamation occurred in 40.7% (11/27) compared with 11.1% (7/63) in patients with breast volume <2500 cm (P=0.002).
Conclusions: Among obese and large-breasted women, there was no increase in acute skin toxicity with the use of HypoRT. HypoRT should be considered in obese and large-breasted women when advanced planning techniques are used.