Metabolic Tumor Volume for Response Prediction in Advanced-Stage Hodgkin Lymphoma

F-18-FDG PET/CT for staging Hodgkin lymphoma may allow for accurate and reliable assessment of the metabolic tumor volume (MTV) as a baseline risk factor. Our aim was to analyze the prognostic impact of MTV measurements obtained by different means in advanced-stage Hodgkin lymphoma patients treated within the German Hodgkin Study Group HD18 trial. Methods: Within HD18, 310 patients underwent F-18-FDG PET/CT scanning for staging, which was available to the central review panel for quantitative analysis. We calculated the MTV by 4 different thresholding methods and performed receiver-operating-characteristic analysis to evaluate the potential for prediction of early response determined by PET after 2 cycles (PET-2) of dose-escalated bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (eBEACOPP). Logistic regression was used to evaluate its prognostic value concerning progression-free survival and overall survival. Results: All of the different MTV calculations predicted PET-2 response to a moderate and comparable degree (area under the curve, 0.62-0.63; P = 0.01-0.06). With none of the measuring methods did the receiver-operating-characteristic curves point to any unique cutoffs; rather, a wide range of possible cutoffs was indicated. None of the MTV measurements was prognostic for progression-free survival (hazard ratio, 1.2-1.5; P = 0.15-0.52) or overall survival (hazard ratio, 1.0-1.5; P = 0.95-0.27). Conclusion: Baseline MTV as determined by different means is a predictive factor for early response to eBEACOPP after 2 cycles. However, value as a prognostic factor after a highly effective PET-2-adapted treatment strategy could not be observed.