Intraoperative electron radiation therapy combined with external beam radiation therapy and limb sparing surgery in extremity soft tissue sarcoma: a retrospective single center analysis of 183 cases

Abstract Background and purpose To report our experience with limb-sparing surgery, IOERT and EBRT in extremity STS. Materials and methods 183 patients were retrospectively analyzed. 78% presented in primary situation, with 80% located in the lower limb. Stage at presentation was: I: 6%, IIa: 25%, IIb: 21%, III: 42%, IV: 7%. The majority showed high-grade lesions (grade 1: 5%, 2: 31%, 3: 64%). IOERT was applied to the tumor bed (median 15 Gy) and preceded (9%) or followed (91%) by EBRT (median 45 Gy) in all patients. Results Median follow-up was 64 months (78 months in survivors). Surgery was complete in 68%, while 32% had microscopic residual disease. 5- and 10-year-LC was 86% and 84%, respectively. LC was significantly higher in primary compared to recurrent disease and tended to be higher after complete resection. Estimated 5- and 10-year-DC was 68% and 66%, while corresponding OS was 77% and 66%, respectively. OS was significantly affected by grading and stage. Severe postoperative complications and late toxicities were observed in 19% and 20%, respectively. Limb-preservation rate was 95% with good function in 83%. Conclusions Combination of limb-sparing surgery, IOERT and EBRT achieved encouraging LC and OS in this unfavorable patient group with acceptable postoperative complications and low rates of late toxicities resulting in a high limb-preservation rate and good functional outcome.