title: Role of PET/CT in the clinical management  of locally advanced pancreatic cancer.
abstract: OBJECTIVE
  To evaluate the role of 18F-fluorodeoxyglucose (FDG) PET/CT in: a) the selection of patients with locally advanced pancreatic cancer for helical tomotherapy with concurrent chemotherapy (HTT-ChT); b) monitoring HTT-ChT treatment efficacy in comparison with contrast-enhanced CT (c.e.CT).
  
  
  METHODS
  Forty-two consecutive patients with unresectable locally advanced pancreatic cancer referred for HTT-ChT were enrolled in the study. All patients were pretreated with induction ChT. Before the beginning of HTT-ChT treatment patients underwent diagnostic c.e.CT (CT0) and FDG PET/CT (PET/CT0) for staging. After staging, patients received HTT-ChT. Three months after the end of HTT-ChT a control c.e.CT (CT1) was done. FDG PET/CT (PET/CT1) was repeated only in patients with positive PET/CT0. PET/CT1 and CT1 were compared with baseline imaging results to assess treatment efficacy.
  
  
  RESULTS
  In 31/42 cases (74%) PET/CT0 documented pathological uptake in pancreatic lesions, while in the remaining 11/42 cases it showed no uptake. In 7/42 (17%) patients, PET/CT0 also detected distant metastases, prompting a change in the therapeutic approach. Compared to PET/CT0, PET/CT1 (n = 18) documented 3 complete metabolic responses, 9 partial metabolic responses, 2 instances of stable metabolic disease, and 4 instances of progressive metabolic disease. In the same group of 18 patients, CT1 showed 0 complete responses, 3 partial responses, 8 instances of stable disease, and 7 instances of progressive disease compared to CT0. Concordance between PET/CT and CT response was seen in 33% of cases. In 50% of cases, PET/CT1 documented a response to therapy that was not evident on CT.
  
  
  CONCLUSIONS
  PET/CT influenced the treatment strategy by detecting distant metastases not documented by CT, thus accurately selecting patients for HTT-ChT after induction ChT. In monitoring treatment efficacy, PET/CT can detect a metabolic response to treatment not identified by CT.
authors.affiliation: Nuclear Medicine, San Raffaele Scientific Institute, Via Olgettina 60, Milan, Italy. picchio.maria@hsr.it
authors.forename: Maria
authors.initials: M
authors.lastname: Picchio
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Giovannini
authors.forename: Paolo
authors.initials: P
authors.lastname: Passoni
authors.forename: Elena
authors.initials: E
authors.lastname: Busnardo
authors.forename: Claudio
authors.initials: C
authors.lastname: Landoni
authors.forename: Giampiero
authors.initials: G
authors.lastname: Giovacchini
authors.forename: Valentino
authors.initials: V
authors.lastname: Bettinardi
authors.forename: Cinzia
authors.initials: C
authors.lastname: Crivellaro
authors.forename: Luigi
authors.initials: L
authors.lastname: Gianolli
authors.forename: Nadia
authors.initials: N
authors.lastname: Di Muzio
authors.forename: Cristina
authors.initials: C
authors.lastname: Messa
mesh_terms: D000328:Adult; D000368:Aged; D059248:Chemoradiotherapy; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology* / Q000628:therapy; D018579:Patient Selection; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000378:metabolism; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18