title: Positron emission tomography-computed tomography (PET-CT) after induction therapy is highly predictive of patient outcome in follicular lymphoma: analysis of PET-CT in a subset of PRIMA trial participants.
abstract: OBJECTIVE
  The utility of [(18)F]fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) in assessing response at the end of induction therapy is well documented in Hodgkin's and diffuse large B-cell lymphomas, but its role in follicular lymphoma (FL) remains undetermined. We investigated the prognostic significance of PET-CT performed after first-line therapy in patients with FL treated in the prospective Primary Rituximab and Maintenance (PRIMA) study.
  
  
  METHODS
  Results of PET-CT scans performed after induction immunochemotherapy were recorded retrospectively. Patients went on to either observation or rituximab maintenance per protocol independent of the PET-CT result. Patient characteristics and outcomes were then evaluated.
  
  
  RESULTS
  Of 122 PET-CT scans performed at the end of the induction immunochemotherapy, 32 (26%) were reported as positive by the local investigator. Initial demographic or disease characteristics did not differ between PET-CT-positive (PET-positive) and PET-CT-negative (PET-negative) patients. PET status correlated with conventional response criteria (P < .001). Patients remaining PET positive had a significantly (P < .001) inferior progression-free survival at 42 months of 32.9% (95% CI, 17.2% to 49.5%) compared with 70.7% (95% CI, 59.3% to 79.4%) in those who became PET negative. PET status, but not conventional response (complete response or complete response unconfirmed v partial response) according to IWC 1999, was an independent predictive factor for lymphoma progression. The risk of death was also increased in PET-positive patients (hazard ratio 7.0; P = .0011).
  
  
  CONCLUSIONS
  [(18)F]FDG PET-CT status at the end of immunochemotherapy induction in patients with FL is strongly predictive of outcome and should be considered a meaningful clinical end point in future studies.
authors: Royal Prince Alfred Hospital and Sydney Medical School, University of Sydney, Sydney, Australia.
authors: Judith
authors: J
authors: Trotman
authors: Marion
authors: M
authors: Fournier
authors: Thierry
authors: T
authors: Lamy
authors: John Francis
authors: JF
authors: Seymour
authors: Anne
authors: A
authors: Sonet
authors: Andrea
authors: A
authors: Janikova
authors: Ofer
authors: O
authors: Shpilberg
authors: Emmanuel
authors: E
authors: Gyan
authors: Hervé
authors: H
authors: Tilly
authors: Jane
authors: J
authors: Estell
authors: Cecily
authors: C
authors: Forsyth
authors: Didier
authors: D
authors: Decaudin
authors: Bettina
authors: B
authors: Fabiani
authors: Jean
authors: J
authors: Gabarre
authors: Bruno
authors: B
authors: Salles
authors: Eric
authors: E
authors: Van Den Neste
authors: Danielle
authors: D
authors: Canioni
authors: Etienne
authors: E
authors: Garin
authors: Michael
authors: M
authors: Fulham
authors: Thierry
authors: T
authors: Vander Borght
authors: Gilles
authors: G
authors: Salles
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058846:Antibodies, Monoclonal, Murine-Derived / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D003520:Cyclophosphamide / Q000008:administration & dosage; D018572:Disease-Free Survival; D004317:Doxorubicin / Q000008:administration & dosage; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008224:Lymphoma, Follicular / Q000000981:diagnostic imaging* / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011241:Prednisone / Q000008:administration & dosage; D016032:Randomized Controlled Trials as Topic; D000069283:Rituximab; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014750:Vincristine / Q000008:administration & dosage
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D000069283:Rituximab; D014750:Vincristine; D004317:Doxorubicin; D003520:Cyclophosphamide; D011241:Prednisone