Five-Year Outcomes and Toxicities Using 3-Dimensional Conformal External Beam Radiation Therapy to Deliver Accelerated Partial Breast Irradiation

Abstract

BackgroundLimited 5-year data exist on clinical outcomes and toxicities for patients undergoing 3-dimensional conformal radiation therapy (3D-CRT) APBI. Patients and MethodsTwo hundred five patients were treated with 3D-CRT APBI between August, 2000 and December, 2011. Cases with > 1 year of follow-up were analyzed for cosmesis, chronic toxicities, and clinical outcomes. Outcome by American Society for Radiation Oncology (ASTRO) Consensus Panel (CP) group were also compared. Rates of excellent and good cosmesis for 3D-CRT were evaluated over time for stability. ResultsOne hundred ninety-two patients were evaluated; median follow-up was 4.8 years (range, 1.0–11.2 years). Seventy-two patients (37.5%) were categorized as ASTRO CP subgroup ‘suitable,' 89 (46.4%) ‘cautionary,' and 31 (16.1%) ‘unsuitable.' At 5 years, the rate of IBTR, regional recurrence, distant metastases, cause-specific survival, and overall survival were 0%, 0%, 2%, 99%, and 92%, respectively. Thirty-seven percent of patients had excellent cosmesis, 44% good cosmesis, 15% fair cosmesis, and 4% poor cosmesis. No statistically significant differences in excellent (37% vs. 37%; P = .99) or good (49% vs. 37%; P = .28) cosmesis were noted between patients with < 5 years follow-up and those with ≥ 5 years follow-up. The rates of grade III fibrosis and telangiectasia were 7.5% and 7.6%, respectively. ConclusionIn the largest group of patients published to date using 3D-CRT to deliver APBI, no local recurrences were noted at 5 years. More than 80% of patients had excellent or good cosmesis.