Intraoperative Radiation Therapy for Locally Advanced and Recurrent Soft-Tissue Sarcomas in Adults

Purpose: To analyze the outcomes of and identify prognostic factors for patients treated with surgery and intraoperative radiotherapy (IORT) for locally advanced and recurrent soft-tissue sarcoma in adults from a single institution. Methods and Materials: We retrospectively reviewed 50 consecutive patients treated with IORT to 62 sites of disease. Primary sites included retroperitoneum-pelvis (78%), extremity (8%), and other (14%). Seventy percent of patients had recurrent disease failing prior surgery (70%) and/or radiation (32%). Mean disease-free interval (DFI) before IORT was 1.9 years (range, 2 weeks-5.4 years). The IORT was delivered with orthovoltage X-rays using individually sized beveled cone applicators. Clinical characteristics were as follows: mean tumor size, 10 cm (range, 1-25 cm); high-grade histologic subtype (72%); and mean dose, 1,159 cGy (range, 600-1,600 cGy). Postoperative radiation or chemotherapy was administered to 37% of IORT Sites and 32% of patients, respectively. Outcomes measured were infield control (IFC), locoregional control (LRC), distant metastasis-free survival (DMFS), disease-specific survival (DSS), and treatment-related complications. Mean and median follow-up of alive patients were 59 and 35 months, respectively. Results: Kaplan-Meier 5-year IFC, LRC, DMFS, and DSS probabilities for the entire group were 55%, 26%, 51%, and 25%, respectively. Prognostic factors found to be significant (p < 0.05) on multivariate analysis were prior DFI and tumor size for LRC, extremity location and leiomyosarcoma histologic subtype for DMFS, and prior DFI for DSS. Our cohort had five Grade 3/4 complications associated with treatment or a 5-year Kaplan-Meier Grade 3/4 complication-free survival rate of 85%. Conclusions: IORT after tumor reductive surgery is well tolerated and seems to confer IFC in carefully selected patients.