title: Use of interim [18F]fluorodeoxyglucose-positron emission tomography is not justified in diffuse large B-cell lymphoma during first-line immunochemotherapy.
abstract: In diffuse large B-cell lymphoma (DLBCL), the response to first-line immunochemotherapy remains somewhat unpredictable. Interim [(18)F]fluorodeoxyglucose-positron emission tomography (FDG-PET) (PET-int) analysis could be an important tool in the prompt shift to intensified regimens. We prospectively evaluated the effectiveness of PET-int carried out at mid-treatment with standard immunochemotherapy in predicting relapse in a series of 85 consecutive patients with DLBCL. PET-int results were dichotomized as positive or negative using the recently validated five-point scale scoring system. This examination was also compared with interim computed tomography (CT-int) and final PET (PET-fin). End-points were: complete remission (CR), positive predictive value (PPV) of refractoriness and relapse, negative predictive value (NPV), overall survival (OS) and progression-free survival (PFS). Observation time was fixed to 24 months unless preceded by a DLBCL-related event. The PPV of PET-int was 58% and the NPV was 77%. CR was correlated with both PET-int and CT-int (p < 0.0001), but in multivariate analysis only CT-int was correlated with CR (p = 0.002). CT-int and PET-fin were predictive of both OS and PFS, whereas PET-int was predictive only of OS (p = 0.013). In Cox regression only PET-fin was predictive for both OS (p = 0.004) and PFS (p = 0.005). PET-int was unable to discriminate those chemosensitive patients who would later relapse. We therefore believe that the use of this expensive radioactive tool is not justified as an interim analysis.
authors.affiliation: Department of Hematology, AO Sant'Andrea, La Sapienza University, Rome, Italy. chrisscox@gmail.com
authors.forename: M Christina
authors.initials: MC
authors.lastname: Cox
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Ambrogi
authors.forename: Valerio
authors.initials: V
authors.lastname: Lanni
authors.forename: Elena
authors.initials: E
authors.lastname: Cavalieri
authors.forename: Sabrina
authors.initials: S
authors.lastname: Pelliccia
authors.forename: Francesco
authors.initials: F
authors.lastname: Scopinaro
authors.forename: Bruno
authors.initials: B
authors.lastname: Monarca
authors.forename: Paolo
authors.initials: P
authors.lastname: Marchetti
authors.forename: M Antonietta Aloe
authors.initials: MA
authors.lastname: Spiriti
mesh_terms: D058846:Antibodies, Monoclonal, Murine-Derived / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001761:Bleomycin / Q000008:administration & dosage; D003520:Cyclophosphamide / Q000008:administration & dosage; D004317:Doxorubicin / Q000008:administration & dosage; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000000981:diagnostic imaging* / Q000188:drug therapy; D008297:Male; D008727:Methotrexate / Q000008:administration & dosage; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D011241:Prednisone / Q000008:administration & dosage; D011379:Prognosis; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D000069283:Rituximab; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data; D014750:Vincristine / Q000008:administration & dosage
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D001761:Bleomycin; D000069283:Rituximab; D014750:Vincristine; D004317:Doxorubicin; D003520:Cyclophosphamide; D011241:Prednisone; D008727:Methotrexate