Introduction: We sought to assess the cosmetic outcomes and the proportion of patients with late radiotherapy toxicity in a group of women with early-stage breast cancer treated with breast-conserving surgery (BCS) and adjuvant radiotherapy using a simultaneous integrated boost (SIB) technique. Methods and Materials:Female patients with early-stage breast cancer (pT1-2 N0-1) treated with BCS and radiotherapy using an SIB technique were identified retrospectively from the departmental database. Radiotherapy consisted of 45 Gy in 25 fractions delivered to the whole breast with a simultaneous forward-planned conformal boost to the tumour bed of 60 Gy in 25 fractions. Demographic data, as well as prospectively collected measures of toxicity and cosmesis, were recorded and analysed. Results: Fifty-five eligible patients were treated between 2009 and 2011. The median age was 61 years (range, 31 to 81 years). Median follow-up was 13.3 months. Late toxicities (including oedema, pigmentation, telangiectasia, fibrosis, osteonecrosis and pain) were graded using Common Terminology Criteria for Adverse Events v3.0 criteria. Grade 0, 1 and 2 toxicities were assigned to 52.8%, 43.4% and 3.8% of patients, respectively. There were no cases of grade 3 or greater toxicity. Ninety-eight per cent had a good or excellent cosmetic outcome based on independent assessment by both the patient and physician. One patient developed a second primary contralateral breast cancer. There were no cases of local recurrence. Conclusion: The use of a conformal SIB technique is proposed as a mode of delivering adjuvant radiotherapy in early-stage breast cancer. This schedule is convenient for the patient given the shortened overall treatment time. Additionally, the SIB technique seems to be well tolerated, with minimal toxicity and acceptable cosmetic outcomes. Finally, there are dosimetric benefits with respect to target coverage and reduction of dose and dose per fraction to organs at risk.

Preoperative RT has low levels of Grades 3 or 4 toxicity, and does not adversely impact surgical management. CT-guided core biopsy is an accurate means of confirming a diagnosis of RPS prior to definitive treatment.

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