Intraoperative electron radiation therapy as an important treatment modality in retroperitoneal sarcoma.
BACKGROUND
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
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 Kaplan-Meier method, Cox regression, and Fisher Exact tests.


RESULTS
Eighteen patients (median age 51 y, 25-76 y) underwent tumor resection with IOERT (median dose 1250 cGy) for primary (n = 13) and recurrent (n = 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 perioperative 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 = 0.5). Four patients with high-grade tumors (57%) and one with a low-grade tumor (11%) developed an LR (P = 0.1). The 2- and 5-y OS rates were 100% and 72%. Two- and 5-y LR rates were 13% and 36%.


CONCLUSIONS
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.
['Sweeting|Raeshell S|RS|', 'Deal|Allison M|AM|', 'Llaguna|Omar H|OH|', 'Bednarski|Brian K|BK|', 'Meyers|Michael O|MO|', 'Yeh|Jen Jen|JJ|', 'Calvo|Benjamin F|BF|', 'Tepper|Joel E|JE|', 'Kim|Hong Jin|HJ|']
D000328:Adult D000368:Aged D003131:Combined Modality Therapy D016208:Databases, Factual D004583:Electrons D005260:Female D005500:Follow-Up Studies D006801:Humans D007432:Intraoperative Period D008297:Male D008875:Middle Aged D009364:Neoplasm Recurrence, Local D011878:Radiotherapy D011879:Radiotherapy Dosage D012186:Retroperitoneal Neoplasms D012307:Risk Factors D012509:Sarcoma D015996:Survival Rate
Retroperitoneal sarcoma Sarcoma Intraoperative radiation