title: High-dose-rate intraoperative radiation therapy (HDR-IORT) for retroperitoneal sarcomas.
abstract: OBJECTIVE
  Retroperitoneal sarcomas represent a formidable challenge to the treating oncologist due to their location, large size, and poor prognosis. The purpose of this study was to determine if the addition of high-dose-rate intraoperative radiation therapy (HDR-IORT) to surgery and external beam radiotherapy (EBRT) would improve the outcome in these patients.
  
  
  METHODS
  Thirty-two patients with retroperitoneal soft tissue sarcoma were prospectively treated according to a protocol that included maximal tumor resection, HDR-IORT, and postoperative EBRT when feasible. Twelve patients presented with primary and 20 with locally recurrent disease. The tumors were high-grade in 20 patients and low-grade in 12 patients. Complete gross resection was achieved in 30 patients. HDR-IORT was given to a dose of 12-15 Gy. Additional EBRT was given to 78% of patients to a dose of 45-50.4 Gy. The two patients with gross residual disease received an additional I-125 permanent implant to a median peripheral dose of 140-160 Gy. The median follow-up was 33 months (range 1-77 mo).
  
  
  RESULTS
  The 5-year actuarial local control rate for the whole group was 62%. For patients with primary disease, the local control rate was 74% compared to 54% in patients with recurrent disease (p = 0.4). The overall 5-year distant metastasis-free survival rate was 82%. In patients with high-grade tumors the rate was 70% vs. 100% in those with low-grade tumors. This difference was statistically significant, p = 0.05. The 5-year disease-free and overall survival rates were 55% and 45%, respectively. The most common type of post-treatment complication was gastrointestinal obstruction (18%) followed by fistula formation (9%), peripheral neuropathy (6%), hydronephrosis (3%), and wound complication (3%).
  
  
  CONCLUSIONS
  We are encouraged by the favorable local control rate and the acceptable morbidity with this new technique applied to a challenging patient population.
authors.affiliation: Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Alektiar
authors.forename: K
authors.initials: K
authors.lastname: Hu
authors.forename: L
authors.initials: L
authors.lastname: Anderson
authors.forename: M F
authors.initials: MF
authors.lastname: Brennan
authors.forename: L B
authors.initials: LB
authors.lastname: Harrison
mesh_terms: D000328:Adult; D000368:Aged; D003131:Combined Modality Therapy; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011183:Postoperative Complications; D011446:Prospective Studies; D011878:Radiotherapy / Q000009:adverse effects; D011879:Radiotherapy Dosage; D012186:Retroperitoneal Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D012509:Sarcoma / Q000532:radiotherapy* / Q000556:secondary / Q000601:surgery; D016019:Survival Analysis