title: Intraoperative electron radiation therapy as an important treatment modality in retroperitoneal sarcoma.
abstract: 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.
authors.affiliation: Division of Surgical Oncology, University of North Carolina School of Medicine at Chapel Hill, Chapel Hill, North Carolina.
authors.forename: Raeshell S
authors.initials: RS
authors.lastname: Sweeting
authors.forename: Allison M
authors.initials: AM
authors.lastname: Deal
authors.forename: Omar H
authors.initials: OH
authors.lastname: Llaguna
authors.forename: Brian K
authors.initials: BK
authors.lastname: Bednarski
authors.forename: Michael O
authors.initials: MO
authors.lastname: Meyers
authors.forename: Jen Jen
authors.initials: JJ
authors.lastname: Yeh
authors.forename: Benjamin F
authors.initials: BF
authors.lastname: Calvo
authors.forename: Joel E
authors.initials: JE
authors.lastname: Tepper
authors.forename: Hong Jin
authors.initials: HJ
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D003131:Combined Modality Therapy; D016208:Databases, Factual / Q000706:statistics & numerical data; D004583:Electrons / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000517:prevention & control; D011878:Radiotherapy / Q000379:methods*; D011879:Radiotherapy Dosage; D012186:Retroperitoneal Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery*; D012307:Risk Factors; D012509:Sarcoma / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery*; D015996:Survival Rate
keywords: Intraoperative radiation; Retroperitoneal sarcoma; Sarcoma