title: Long-term results of intraoperative electron beam irradiation (IOERT) for patients with unresectable pancreatic cancer.
abstract: BACKGROUND
  To analyze the effects of a treatment program of intraoperative electron beam radiation therapy (IOERT) and external beam radiation therapy and chemotherapy on the outcome of patients with unresectable or locally advanced pancreatic cancer.
  
  
  METHODS
  From 1978 to 2001, 150 patients with unresectable and nonmetastatic pancreatic cancer received IOERT combined with external beam radiation therapy and 5-fluorouracil-based chemotherapy for definitive treatment.
  
  
  RESULTS
  The 1-, 2-, and 3-year actuarial survival rates of all 150 patients were 54%, 15%, and 7%, respectively. Median and mean survival rates were 13 and 17 months, respectively. Long-term survival has been observed in 8 patients. Five patients have survived beyond 5 years and 3 more between 3 and 4 years. There was a statistically significant correlation of survival to the diameter of treatment applicator (a surrogate for tumor size) used during IOERT. For 26 patients treated with a small-diameter applicator (5 cm or 6 cm), the 2- and 3-year actuarial survival rates were 27% and 17%, respectively. In contrast, none of the 11 patients treated with a 9-cm-diameter applicator survived beyond 18 months. Intermediate survival rates were seen for patients treated with a 7- or 8-cm-diameter applicator. Operative mortality was 0.6%, and postoperative and late complications were 20% and 15%, respectively.
  
  
  CONCLUSIONS
  A treatment strategy employing IOERT has resulted in long-term survival in 8 of 150 patients with unresectable pancreatic cancer. Survival benefit was limited to patients with small tumors. Enrollment of selected patients with small tumors into innovative protocols employing this treatment approach is appropriate.
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts, USA. willett@radonc.duke.edu
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Willett
authors.forename: Carlos Fernandez
authors.initials: CF
authors.lastname: Del Castillo
authors.forename: Helen A
authors.initials: HA
authors.lastname: Shih
authors.forename: Saveli
authors.initials: S
authors.lastname: Goldberg
authors.forename: Peter
authors.initials: P
authors.lastname: Biggs
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Clark
authors.forename: Gregory
authors.initials: G
authors.lastname: Lauwers
authors.forename: David P
authors.initials: DP
authors.lastname: Ryan
authors.forename: Andrew X
authors.initials: AX
authors.lastname: Zhu
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Warshaw
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D021441:Carcinoma, Pancreatic Ductal / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D016896:Treatment Outcome