Safety and Efficacy of Hypofractionated Preoperative Radiation Therapy in Retroperitoneal Sarcoma: A Comparative Study With Conventional Fractionation.

Abstract

The role of preoperative radiation therapy (RT) in retroperitoneal sarcoma (RPS) remains controversial across histologic subtypes. Conventional fractionated RT (ConvRT) is the current standard, but hypofractionated RT (HypoRT) is gaining interest, particularly for soft-tissue sarcomas. This study aimed to compare the safety and efficacy of HypoRT (10 fractions) with ConvRT in patients with RPS. We retrospectively reviewed 55 patients with RPS who received preoperative RT followed by surgery at a single tertiary institution between 2017 and 2024. All patients underwent intensity modulated RT with simultaneous integrated boost techniques. The HypoRT group (n = 15) received 50/35 Gy in 10 fractions, and the ConvRT group (n = 40) received 62.5/45 Gy in 25 fractions. We assessed surgical complications (Clavien-Dindo grade ≥3) and prolonged postoperative hospitalization (≥14 days). Baseline characteristics were comparable. HypoRT did not increase grade ≥3 complications (33.3% vs 25.0%, P = .735) or hospital stay (median, 16 vs 13 days; P = .684). Older age was associated with severe complications (P = .027), whereas larger tumors and longer operation time correlated with extended hospitalization (P = .018 and P = .024, respectively). With a median follow-up of 33 months, 3-year local recurrence-free survival (71.5% vs 48.9%, P = .329), progression-free survival (59.3% vs 44.4%, P = .612), and overall survival (84.9% vs 80.0%, P = .578) were comparable between groups. HypoRT in 10 fractions appears feasible, without an apparent increase in perioperative morbidity and may offer a potential alternative to ConvRT in patients with resectable RPS.