title: The prognostic value of mid- and post-treatment [(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET) in indolent follicular lymphoma.
abstract: BACKGROUND
  [(18)F]fluorodeoxyglucose positron emission tomography (PET) is a useful staging investigation for follicular lymphoma (FL). Recent studies have shown that positive post-treatment PET is also a strong predictor of inferior overall survival.
  
  
  OBJECTIVE
  To evaluate the predictive value of mid- and post-treatment PET in FL patients with respect to progression-free survival (PFS) and overall survival (OS).
  
  
  METHODS
  We included 57 patients with indolent FL (grade 1, 2, and 3a) who received induction chemotherapy. Mid- and post-treatment PET results were correlated with PFS and OS retrospectively and analysed using Kaplan-Meier survival analysis and Cox regression.
  
  
  RESULTS
  Post-treatment PET was predictive of OS (mean OS 95.2 vs. 45.0 months for PET-negative vs. PET-positive, p < 0.001) and showed a trend towards significance for PFS (mean PFS 74.4 vs. 38.2 months for PET- vs. PET+, p = 0.083). 3-year PFS for post-treatment PET- and PET+ patients were 72 and 30 %, respectively. 3-year OS were 96 and 60 %, respectively. Mid-treatment PET was not predictive of PFS (mean PFS 78.5 vs. 51.0 months for PET- vs. PET+, p = 0.35) nor OS (mean OS 89.9 vs. 76.6 months for PET- vs. PET+, p = 0.92).
  
  
  CONCLUSIONS
  Post-treatment PET is predictive of OS in indolent FL. It identifies patients who might benefit from more intensive follow-up, enrolment in clinical trials or second-line therapy. Mid-treatment PET scan results did not appear to predict long-term treatment outcomes.
authors.affiliation: University of New South Wales, Sydney, Australia.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Lu
authors.forename: Michael
authors.initials: M
authors.lastname: Lin
authors.forename: Paul
authors.initials: P
authors.lastname: Downe
authors.forename: Shanley
authors.initials: S
authors.lastname: Chong
authors.forename: Silvia
authors.initials: S
authors.lastname: Ling
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D018572:Disease-Free Survival; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D053208:Kaplan-Meier Estimate; D008224:Lymphoma, Follicular / Q000175:diagnosis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D019788:Fluorodeoxyglucose F18