title: 18Fluorodeoxyglucose PET is prognostic of progression-free and overall survival in locally advanced pancreas cancer treated with stereotactic radiotherapy.
abstract: OBJECTIVE
  This study analyzed the prognostic value of positron emission tomography (PET) for locally advanced pancreas cancer patients undergoing stereotactic body radiotherapy (SBRT).
  
  
  METHODS
  Fifty-five previously untreated, unresectable pancreas cancer patients received a single fraction of 25-Gy SBRT sequentially with gemcitabine-based chemotherapy. On the preradiation PET-CT, the tumor was contoured and the maximum standardized uptake value (SUVmax) and metabolic tumor burden (MTB) were calculated using an in-house software application. High-SUVmax and low-SUVmax subgroups were created by categorizing patients above or below the median SUVmax. The analysis was repeated to form high-MTB and low-MTB subgroups as well as clinically relevant subgroups with SUVmax values of <5, 5-10, or >10. Multivariate analysis analyzing SUVmax, MTB, age, chemotherapy cycles, and pretreatment carbohydrate antigen (CA)19-9 was performed.
  
  
  RESULTS
  For the entire population, median survival was 12.7 months. Median survival was 9.8 vs.15.3 months for the high- and low- SUVmax subgroups (p <0.01). Similarly, median survival was 10.1 vs. 18.0 months for the high MTB and low MTB subgroups (p <0.01). When clinical SUVmax cutoffs were used, median survival was 6.4 months in those with SUVmax >10, 9.5 months with SUVmax 5.0-10.0, and 17.7 months in those with SUVmax <5 (p <0.01). On multivariate analysis, clinical SUVmax was an independent predictor for overall survival (p = 0.03) and progression-free survival (p = 0.03).
  
  
  CONCLUSIONS
  PET scan parameters can predict for length of survival in locally advanced pancreas cancer patients.
authors.affiliation: Department of Radiation Oncology at Fraser Valley Cancer Centre, Surrey, Canada.
authors.forename: Devin
authors.initials: D
authors.lastname: Schellenberg
authors.forename: Andy
authors.initials: A
authors.lastname: Quon
authors.forename: A Yuriko
authors.initials: AY
authors.lastname: Minn
authors.forename: Edward E
authors.initials: EE
authors.lastname: Graves
authors.forename: Pamela
authors.initials: P
authors.lastname: Kunz
authors.forename: James M
authors.initials: JM
authors.lastname: Ford
authors.forename: George A
authors.initials: GA
authors.lastname: Fisher
authors.forename: Karyn A
authors.initials: KA
authors.lastname: Goodman
authors.forename: Albert C
authors.initials: AC
authors.lastname: Koong
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Chang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use; D018395:CA-19-9 Antigen / Q000097:blood; D003841:Deoxycytidine / Q000031:analogs & derivatives / Q000627:therapeutic use; D018572:Disease-Free Survival; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000401:mortality / Q000601:surgery; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D016634:Radiosurgery; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D000093542:Gemcitabine
chemical_list: D000964:Antimetabolites, Antineoplastic; D018395:CA-19-9 Antigen; D019275:Radiopharmaceuticals; D003841:Deoxycytidine; D019788:Fluorodeoxyglucose F18; D000093542:Gemcitabine