Perioperative interstitial brachytherapy for soft tissue sarcomas: prognostic factors and long-term results of 155 patients

Abstract

Background: The goal of this study was to evaluate the efficacy of temporary interstitial brachytherapy (BRT) for patients undergoing combined modality management of soft tissue sarcomas (STS).

Methods: From January 1990 to December 2003, 155 adults 18-88 years of age (median = 42 years) with STS who had received BRT as part of locoregional treatment were included in this review. Sixty-four percent were males. Sixty-nine percent had primary lesions. Sixty percent had lesions involving the lower extremities. Spindle cell sarcoma (28%) and synovial sarcoma (16%) were the most common histologic types and 51% had grade III lesions. Treatment included wide local excision of primary tumor with BRT with or without external beam radiotherapy (EBRT).

Results: After a median followup of 45 months, the local control (LC), disease-free survival (DFS), and overall survival (OS) for the entire cohort was 71%, 57%, and 73%, respectively. DFS was superior for superficial tumors compared with that for deep tumors (96% vs. 54%, P =.02). Patients with a tumor less than 5 cm had superior OS (88% vs. 63%, P =.05). Cumulative radiotherapy dose greater than 60 Gy had a significant positive impact on LC (P = .003), DFS (P =.003), and OS (P =.048). Subcutaneous fibrosis (21%) was the major complication.

Conclusions: Temporary perioperative iridium-192 interstitial BRT with or without EBRT after function-preserving surgery results in satisfactory outcome in patients with STS. Both low dose rate and high dose rate BRT are equivalent in terms of disease control and complications when used alone or in combination with EBRT. BRT results in fewer complications compared with the combination of BRT and EBRT.