Local recurrence (LR) rates in patients with retroperitoneal sarcoma (RPS) are high, ranging from 40% to 80%, with no deﬁnitive studies describing the best way to administer radiation. Intraoperative electron beam radiation therapy (IOERT) provides a theoretical advantage for access to the tumor bed with reduced toxicity to surrounding structures. The goal of this study was to evaluate the role of IOERT in high-risk patients.
METHODS AND MATERIALS
An institutional review board approved, single institution sarcoma database was queried to identify patients who received IOERT for treatment of RPS from 2/2001 to 1/2009. Data were analyzed using the Kaplane—Meier method, Cox regression, and Fisher Exact tests.
Eighteen patients (median age 51 y, 25e76 y) underwent tumor resection with IOERT (median dose 1250 cGy) for primary (n ¼ 13) and recurrent (n ¼ 5) RPS. Seventeen patients received neoadjuvant radiotherapy. Eight high-grade and 10 low-grade tumors were identiﬁed. Median tumor size was 15 cm. Four patients died and two in the peri-operative period. Median follow-up of survivors was 3.6 y. Five patients (31%) developed an LR in the irradiated ﬁeld. Three patients with primary disease (25%) and two (50%) with recurrent disease developed an LR (P ¼ 0.5). Four patients with high-grade tumors (57%) and one with a low-grade tumor (11%) developed an LR (P ¼ 0.1). The 2- and 5-y OS rates were 100% and 72%. Two- and 5-y LR rates were 13% and 36%.
Using a multidisciplinary approach, we have achieved low LR rates in our high-risk patient population indicating that IOERT may play an important role in managing these patients.