Sequencing radiotherapy for soft tissue sarcoma when re-resection is planned

Abstract

Purpose To evaluate whether disease outcome for localized soft-tissue sarcoma (STS) excised before referral to a specialist center and there re-resected was influenced by the timing of radiation therapy (XRT)—before or after re-resection. Methods and materials Two hundred ninety-five consecutive patients with localized grossly excised STS were retrospectively evaluated for local control, freedom from metastasis, disease-free survival, and disease-specific survival, according to whether they had XRT before (121) or after (174) re-resection of their tumor bed. Univariate and multivariate statistical techniques were employed. Results At re-resection, residual STS was found in 159 patients (54%), including gross tumor in 73 (25%). The incidence of residual disease was lower in those receiving preoperative XRT (median dose 50 Gy) (36%) than in those having postoperative RT (median dose 60 Gy) (54%) ( p = 0.024). With a median follow-up of 9.1 years, the local control rates for all patients at 5, 10, and 15 years were 86%, 84%, and 81%, respectively, and there were no differences between the two XRT sequences. In multivariate regression, there was no evidence that XRT sequence influenced local control, metastatic control, disease-free survival, or disease-specific survival. There was a trend toward fewer XRT-related late complications with preoperative XRT, but this was not significant, and the incidence of complications was low (5% at 15 years). Conclusions Patients who present after total but oncologically inadequate excision of STS can receive approximately 50 Gy before re-resection or approximately 60 Gy after re-resection, with approximately equivalent, satisfactory local control and overall disease outcome. Decisions as to the most appropriate treatment sequence for any individual patient can be made regardless of considerations as to the effectiveness of one sequence compared with the other.