Role of [18F]-FDG-PET/MDCT in evaluating early response in patients with Hodgkin's lymphoma.

PURPOSE: The authors evaluated the prognostic role of 18-fluoro-fluorodeoxyglucose positron emission tomography/multidetector computed tomography ([(18)F]-FDG PET/MDCT) in treating patients with Hodgkin's lymphoma (HL). MATERIALS AND METHODS: We retrospectively evaluated 132 patients with HL studied with PET/MDCT before the start of chemotherapy (CTX) for staging purposes and again after two CTX cycles with [doxorubicin (Adriblastin), bleomycin, vinblastine, dacarbazine (ABVD_] (interim PET/MDCT), at least 30 days after the end of the last CTX cycle and/or 3 months after the end of radiotherapy, if delivered (final PET-MDCT). RESULTS: Interim PET-MDCT was negative in 104/132 patients (79%), and their final PET-MDCT showed complete remission in 102/104 (98%) of cases, with disease recurrence/persistence in two (2%). In the remaining 28 (21%) patients, interim PET-MDCT revealed an early response in 68% of cases and chemoresistance with disease progression in 32% of cases; in these 28 patients, final PET-MDCT showed a lack of response to treatment in 43% of cases (43%) and complete remission in 57% of cases. Statistical analysis of these data showed that interim PET-MDCT had a negative predictive value of 98% and a positive predictive value of 42%, with values of sensitivity, specificity and diagnostic accuracy of 85.7%, 86.4% and 86.4%, respectively. CONCLUSIONS: Interim PET-MDCT has a reliable prognostic role in diagnosis and treatment of patients with HL, as it helps predict which patients are more likely to achieve a complete response at the end of treatment. PET/MDCT may also lead to a change in treatment, with reduced treatment-related toxic effects and significantly reduced total costs.