title: Stereotactic radiotherapy for unresectable adenocarcinoma of the pancreas.
abstract: BACKGROUND
  The authors report on the local control and toxicity of stereotactic body radiotherapy (SBRT) for patients with unresectable pancreatic adenocarcinoma.
  
  
  METHODS
  Seventy-seven patients with unresectable adenocarcinoma of the pancreas received 25 gray (Gy) in 1 fraction. Forty-five patients (58%) had locally advanced disease, 11 patients (14%) had medically inoperable disease, 15 patients (19%) had metastatic disease, and 6 patients (8%) had locally recurrent disease. Nine patients (12%) had received prior chemoradiotherapy. Sixteen patients (21%) received between 45 to 54 Gy of fractionated radiotherapy and SBRT. Various gemcitabine-based chemotherapy regimens were received by 74 patients (96%), but 3 patients (4%) did not receive chemotherapy until they had distant failure.
  
  
  RESULTS
  The median follow-up was 6 months (range, 3-31 months) and, among surviving patients, it was 12 months (range, 3-31 months). The overall rates of freedom from local progression (FFLP) at 6 months and 12 months were 91% and 84%, respectively. The 6- and 12-month isolated local recurrence rates were 5% and 5%, respectively. There was no difference in the 12-month FFLP rate based on tumor location (head/uncinate, 91% vs body/tail, 86%; P = .52). The progression-free survival (PFS) rates at 6 months and 12 months were 26% and 9%, respectively. The PFS rate at 6 months was superior for patients who had nonmetastatic disease versus patients who had metastatic disease (28% vs 15%; P = .05). The overall survival (OS) rates at 6 months and 12 months from SBRT were 56% and 21%, respectively. Four patients (5%) experienced grade > or = 2 acute toxicity. Three patients (4%) experienced grade 2 late toxicity, and 7 patients (9%) experienced grade > or = 3 late toxicity. At 6 months and 12 months, the rates of grade > or = 2 late toxicity were 11% and 25%, respectively.
  
  
  CONCLUSIONS
  SBRT for pancreatic adenocarcinoma was effective for local control with associated risk of toxicity and should be used with rigorous attention to quality assurance. Efforts to reduce complications are warranted. Distant metastases account for the vast majority of disease-related mortality.
authors.affiliation: Department of Radiation Oncology, Stanford University Medical Center, Stanford, California 94305-5847, USA.
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Chang
authors.forename: Devin
authors.initials: D
authors.lastname: Schellenberg
authors.forename: John
authors.initials: J
authors.lastname: Shen
authors.forename: Jeff
authors.initials: J
authors.lastname: Kim
authors.forename: Karyn A
authors.initials: KA
authors.lastname: Goodman
authors.forename: George A
authors.initials: GA
authors.lastname: Fisher
authors.forename: James M
authors.initials: JM
authors.lastname: Ford
authors.forename: Terry
authors.initials: T
authors.lastname: Desser
authors.forename: Andrew
authors.initials: A
authors.lastname: Quon
authors.forename: Albert C
authors.initials: AC
authors.lastname: Koong
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D010190:Pancreatic Neoplasms / Q000473:pathology / Q000601:surgery*; D016634:Radiosurgery / Q000009:adverse effects; D012008:Recurrence; D012189:Retrospective Studies; D016019:Survival Analysis; D013997:Time Factors