Preoperative Radiation Therapy is Not Associated with Postoperative Complications in Patients with Retroperitoneal Sarcoma.

Background: The role of preoperative radiation therapy (RT) in the management of retroperitoneal sarcomas (RPS) remains controversial. A legitimate concern is the potential for worse outcomes after surgery for RPS with preoperative RT.

Objective: The purpose of this study was to evaluate the impact of preoperative (± intraoperative) RT on postoperative complications in patients undergoing surgery for RPS.

Methods: A total of 99 patients who underwent curative-intent surgery for primary RPS of any histology after preoperative RT from 2003 to 2021 were analyzed. Univariate and multivariate logistic regression analyses were performed to identify factors associated with postoperative morbidity and mortality.

Results: The median preoperative RT dose was 57.4 Gy, and 17 patients received intraoperative RT to a median dose of 10 Gy. The median number of organs resected was two. Postoperative complications within 30 days of surgery occurred in 47% of patients, including severe complications (Clavien-Dindo grades ≥IIIa) in 20% of patients. The 90-day mortality rate was 2%. On multivariate analysis, concomitant vascular resection was the only significant predictor of severe postoperative complications (odds ratio 8.76; p = 0.0069). Despite increasing median preoperative RT doses from 50.4 Gy in 2003-2012 to 63 Gy (on a clinical trial) in 2013-2021, severe postoperative morbidity rates actually decreased from 26.3% to 16.1% (p = 0.303).

Conclusion: The administration of preoperative (± intraoperative) RT to patients with RPS resulted in similar postoperative complications as reported after surgery alone. Continuous advances in surgical and radiotherapeutic expertise resulted in lower complication rates over time despite increasing radiation doses.