Three-Fraction Intracavitary Accelerated Partial Breast Brachytherapy: Early Provider and Patient-Reported Outcomes of a Novel Regimen

Purpose: To report early adverse events and patient-reported outcomes (PROs) of 3-fraction intracavitary catheter-based partial breast brachytherapy (ICBB). Materials and Methods: Eligible women ≥50 years of age with ≤2.5-cm, lymph node–negative invasive or in situ breast cancer underwent breast-conserving surgery and placement of a brachytherapy applicator. ICBB was initiated on the second weekday after surgery and prescribed to 21 Gy in 3 once-daily fractions. Common Terminology Criteria for Adverse Events, version 4.0; 10-point linear analog scale assessment; the PRO version of the Common Terminology Criteria for Adverse Events; and the Harvard Breast Cosmesis Scale were used for provider and patient-reported assessments. Results: Seventy-three women were treated for invasive (79%) or in situ (21%) breast cancer. The median time to completion of surgery and radiation therapy was 6 days. After 14-months median follow-up, 2 patients (3%) had developed breast infections that resolved with oral antibiotics. There was no other treatment-associated adverse event grade ≥2. The grade 1 seroma rate at 3 months was 20%, which dropped to 8% at 12 months; no events required intervention. At 12 months, 91% of patients reported an overall quality of life score as ≥8 of 10, and patient-reported cosmesis was good or excellent in 95%. All patients are alive without relapse at the last follow-up. Conclusions: Three-fraction ICBB is associated with low rates of early provider and patient- reported adverse events and compares favorably with early outcomes of more protracted ICBB regimens, including twice-daily (3.4 Gy × 10) fractionation studied in the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-39. Further investigation is warranted.