Prospective analysis of toxicity in patients treated with strut-adjusted volume implant for early-stage breast cancer

Purpose We report the toxicity of patients treated with strut-adjusted volume implant (SAVI) for accelerated partial breast irradiation treated at our institution. Methods and Materials Patients treated from January 2013 to July 2015 with SAVI planned for 10 b.i.d. fractions for a total dose of 34 Gy were included. Acute and late toxicities were prospectively collected on patients in followup and graded by the Common Terminology Criteria for Adverse Events, version 4.0. Results A total of 132 patients were included, with 1 patient having synchronous breast cancer treated in each breast. Median followup was 20.0 months (range, 2.7–37.4 months). The median age at diagnosis was 61 years (range, 41–83 years). Forty-two lesions (32%) were in situ, 88 lesions (66%) were Stage 1, and 3 (2%) lesions were Stage 2. The median planning target volume was 58.2 cc (range, 24.2–109.9 cc), median V₁₅₀ was 26.3 cc (range, 11.5–47.5 cc), and median V₂₀₀ was 13.0 cc (range, 6.3–26.1 cc). On a pain scale of 0–10 (10 = worst pain), pain was worst on Day 2 of treatment, with an average score of 0.46. There was one acute skin infection; there were three late skin infections, two of which was Grade 3. Other late toxicities were Grade 1 or 2: hyperpigmentation (44%), telangiectasia (0.8%), seroma (9%), fat necrosis (5%), and fibrosis (12%). Crude local recurrence rate was 4%. Conclusion SAVI is a safe treatment option for patients who are candidates for accelerated partial breast irradiation. Local control seems to be excellent, but longer followup is needed.