Purpose: A prospective randomized trial evaluating adjuvant brachytherapy for soft tissue sarcomas was conducted between July 1982 and July 1987.
Methods and materials: One hundred twenty-six patients with soft tissue sarcoma of the extremity or superficial trunk (STS) underwent grossly complete resection with limb-sparing surgery. Intra-operatively, patients were randomized to receive either adjuvant brachytherapy (BRT) or no further therapy (no BRT). BRT consisted of an Iridium-192 implant which delivered 4200-4500 cGy over 4-6 days. Total hospital stay for combined surgery and BRT was 10-14 days. Patients in each group were well matched with respect to age, sex, site, tumor size, depth, histologic type, and grade. Median follow-up is 66.5 months for all living patients.
Results: At 5 years, local control was 82% in the BRT group vs. 67% in the no BRT group (p = .049). When analyzed by histologic grade, high grade tumors had local control of 90% with BRT vs. 65% with no BRT (p = .013). There was no difference in local control in the low grade patients in either arm. At 5 years, the proportion free of distant metastases was approximately 76% in both arms, with no difference between BRT and no BRT. When analyzed by grade, high grade patients had a similar proportion free of distant metastasis in the BRT vs. no BRT arms despite improved local control in those receiving BRT. Similarly, the disease-specific survival for all patients at 5 years was 81% for BRT vs. 80% for no BRT (p = NS). When analyzed by grade, and treatment (BRT vs. no BRT), 5-year disease-specific survival for high grade was the same in both groups.
Conclusions: Adjuvant BRT significantly improves local control in completely resected STS. This improvement is confined to patients with high grade histology. BRT provides excellent local control in this group, and significantly shortens the treatment time when compared to adjuvant external beam radiation. However, the improved local control does not translate into either decreased distant metastasis or increased disease-specific survival.