Long-term cosmetic results and toxicity after accelerated partial-breast irradiation

BACKGROUND The objective of this study was to assess the cosmesis and toxicities in patients with early-stage breast carcinoma who received treatment with accelerated partial breast irradiation (APBI) using interstitial brachytherapy. METHODS From April 1993 to December 2001, 199 patients with Stage I–II breast carcinoma received breast-conserving therapy with APBI to the tumor bed alone through a low-dose-rate (LDR) or high-dose-rate (HDR) implant. A template guide was used. The LDR dose was 50 Gray (Gy) over 96 hours; the outpatient HDR implant delivered 32 Gy in 8-Gy or 34 Gy in 10-Gy twice-daily fractions. Cosmesis (Harvard criteria) and toxicities (Radiation Therapy Oncology Group guidelines) were assessed at ≤ 6 months, 2 years, and 5 years. RESULTS The median follow up was 6.4 years. Breast pain, edema, erythema, and hyperpigmentation all diminished over time. Breast fibrosis and hypopigmentation increased until the 2-year mark and then stabilized. Fat necrosis and telangiectasia increased over time, with a fat necrosis rate of 11% at 5 years. Nearly all telangiectasias (34% at 5 yrs) were Grade 1 (< 2 mm). The remaining toxicities were Grade 1 at all follow-up intervals. Infections (11%) occurred predominantly within the first month after treatment. Good-to-excellent cosmetic outcomes were noted in 95–99% of patients over time; cosmetic results stabilized at 2 years with excellent results increased out to 5 years. CONCLUSIONS APBI with interstitial brachytherapy resulted in mild chronic toxicities, the majority of which diminished or reached a plateau over time. Long-term cosmesis was good to excellent in 95–99% of patients and stabilized at 2 years. Cancer 2006. © 2006 American Cancer Society.