Reduction in Radiation-Induced Morbidity by Use of an Intercurrent Boost in the Management of Early-Stage Breast Cancer

Purpose

Electron or photon boost immediately following whole-breast irradiation performed after conservation surgery for early-stage breast cancer is the accepted standard of care. This regimen frequently results in Grade III dermatitis, causing discomfort or treatment interruption. Herein, we compare patients treated with whole-breast irradiation followed by boost compared with a cohort with a planned intercurrent radiation boost.

Methods and Materials

The records of 650 consecutive breast cancer patients treated at Allegheny General Hospital (AGH) between 2000 and 2008 were reviewed. Selected for this study were 327 patients with T1 or T2 tumors treated with external beam radiotherapy postlumpectomy. One hundred and sixty-nine patients were treated by whole-breast radiotherapy (WBRT) followed by boost at completion. One hundred fifty-eight were treated with a planned intercurrent boost (delivered following 3,600 cGy WBRT). The mean whole breast radiation dose in the conventionally treated group was 5,032 cGy (range, 4500–5400 cGy), and the mean whole breast dose was 5,097 cGy (range, 4860–5040 cGy) in the group treated with a planned intercurrent boost.

Results

The occurrence of Grade III dermatitis was significantly reduced in the WBRT/intercurrent boost group compared with the WBRT/boost group (0.6% vs. 8.9%), as was the incidence of treatment interruption (1.9% vs. 14.2%). With a median follow-up of 32 months and 27 months, respectively, no significant difference in local control was identified.

Conclusions

Patients treated with intercurrent boost developed less Grade III dermatitis and unplanned treatment interruptions with similar local control.

Breast cancer, Boost, Radiation, Electrons, Intercurrent