(P 366) WOUND COMPLICATIONS AFTER ULTRA-HYPOFRACTIONATED NEOADJUVANT RADIATION FOR SOFT TISSUE SARCOMA: WHAT IS OPTIMAL SURGICAL TIMING?

Objective: Ultra-hypofractionated radiation therapy (UHFR) for soft tissue sarcomas is an alternative to conventionally fractionated radiation therapy (CFR) and may be associated with higher rates of wound complications. Optimal timing between radiation and surgery is unknown. We compared rates of wound complications for patients who received CFR or UHFR and within UHFR, compared immediate surgery (UHFR-IS) to delayed surgery (UHFR-DS).

Methods: Patients with extremity and truncal soft tissue sarcoma who received neoadjuvant radiation and surgery between January 2016 and June 2025 were retrospectively identified. CFR was defined as 45-50 Gy in 25 fractions and UHFR radiation was defined as 30 Gy in 5 fractions. Patients who received UHFR were dichotomized as having undergone surgery within seven days (UHFR-IS) or greater than seven days (UHFR-DS) post-radiation. Wound complications (IV antibiotics, percutaneous drain placement, reoperation) were compared between groups.

Results: In total, 126 patients were identified. Of these, 94 received CFR (median 38 days between radiation and surgery), 22 received UHFR-IS (median one day between radiation and surgery), and 10 received UHFR-DS (median 35 days between radiation and surgery). Neither complication rates (CFR: 37.2%, 35/94; UHFR-IS: 40.9%, 9/22; UHFR-DS: 70%, 7/10 , p = 0.13) nor the rate of complications requiring reoperation (CFR: 35.1%, 33/94; UHFR-IS: 31.8%, 7/22; UHFR-DS: 70%, 7/10 , p = 0.08) differed between groups. Neither the rates of wound complication (p=0.25) nor complications requiring reoperation (p=0.10) above differed between UHFR-IS and UHFR-DS groups.

Conclusion: In our single-institution retrospective series, a strategy of neoadjuvant UHFR was not associated with higher rates of wound complications compared to CFR. Delaying surgery after UHFR did not change complication rates. Further research is needed to optimize neoadjuvant radiation strategies in this population.

Results of Neoadjuvant Conventional Radiation vs Ultra-hypofractionated Radiation Therapy and Post-Operative Wound Complications