LONG-TERM RESULTS OF A PROSPECTIVE RANDOMIZED TRIAL OF ADJUVANT BRACHYTHERAPY IN SOFT-TISSUE SARCOMA

Purpose: This trial was performed to evaluate the impact of adjuvant b rachytherapy on local and systemic recurrence rates in patients with s oft tissue sarcoma, Patients and Methods: In a single-institution pros pective randomized trial, 164 patients were randomized intraoperativel y to receive either adjuvant brachytherapy (BRT) or no further therapy (no BRT) after complete resection of soft tissue sarcomas of the extr emity or superficial trunk. The adjuvant radiation was administered by iridium-199 implant, which delivered 42 to 45 Gy over 4 to 6 days. Th e two study groups had comparable distributions of patient and tumor f actors, including age, sex, tumor site, tumor size, and histologic typ e and grade, Results: With a median follow-up time of 76 months, the 5 -year actuarial local control rates were 82% and 69% in the BRT and no BRT groups (P = .04), respectively. Patients with high-grade lesions had local control rates of 89% (BRT) and 66% (no BRT) (P = .0025), BRT had no impact on local control in patients with low-grade lesions (P = .49). The 5-year freedom-from-distant-recurrence rates were 83% and 76% in the BRT and no BRT groups (P = .60), respectively, Analysis by histologic grade did not demonstrate an impact of BRT on the developme nt of distant metastasis, despite the improvement in local control not ed in patients with high-grade lesions. The 5-year disease-specific su rvival rates for the BRT and no BRT groups were 84% and 81% (P = .65), respectively, with no impact of BRT regardless of tumor grade. Conclu sion: Adjuvant brachytherapy improves local control after complete res ection of soft tissue sarcomas. This improvement in local control is l imited to patients with high-grade histopathology. The reduction in lo cal recurrence in patients with high-grade lesions is not associated w ith a significant reduction in distant metastasis or improvement in di sease-specific survival.