A novel schedule of accelerated partial breast radiation using intensity-modulated radiation therapy in elderly patients: survival and toxicity analysis of a prospective clinical trial
BACKGROUND Limited 5-year data exist on clinical outcomes and toxicities for patients undergoing 3-dimensional conformal radiation therapy (3D-CRT) APBI. PATIENTS AND METHODS Two 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. RESULTS One 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. CONCLUSION In 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.