Baseline 18F-FDG PET/CT May Portend the Prognosis of Patients With Waldenstrom Macroglobulinemia/Lymphoplasmacytic Lymphoma After First-Line Treatment

Purpose The outcome of patients with Waldenstrom macroglobulinemia/lymphoplasmacytic lymphoma (WM/LPL) is variable. We aim to study if baseline F-18-FDG PET/CT has some prognostic significance in WM/LPL. Methods Thirty-three patients with newly diagnosed WM/LPL who underwent baseline F-18-FDG PET/CT and received active treatment thereafter were recruited in this retrospective study. Semiquantitative indices of baseline F-18-FDG PET/CT were measured as total lesion glycolysis (TLG), metabolic tumor volume (MTV), and SUVmax. The patients were followed up for at least 3 years or until reaching the endpoint, which were defined as progression-free survival (PFS) and the time to next treatment (TTNT). Results The overall response rate of the first-line treatment in the recruited patients was 84.8% (28/33). The 3-year PFS and overall survival rates were 56.3% and 89.3%, respectively. Patients with PFS <36 months and TTNT <36 months showed TLG and MTV significantly higher than those with PFS >= 36 months and TTNT >= 36 months (P < 0.05). SUVmax in patients with PFS <36 months was significantly higher than those with PFS >= 36 months (P = 0.033). Receiver operating characteristic analysis demonstrated that cutoff values of TLG >291.28 SUVbw * mL, MTV >108.78 mL, and SUVmax >3.16 were optimal for predicting PFS 291.28 SUVbw * mL and MTV >108.78 mL were predictive for shorter PFS (P = 0.003) and TTNT (P = 0.002). In multivariate analysis, TLG >291.28 SUVbw * mL and MTV >108.78 mL were independent predictors for shorter PFS (hazard ratio, 3.06; 95% confidence interval, 1.09-8.57; P = 0.033) and TTNT (hazard ratio, 10.01; 95% confidence interval, 2.56-39.22; P = 0.001). Conclusions The metabolic indices of TLG and MTV in baseline F-18-FDG PET/CT were independent prognostic factors to predict PFS and TTNT in patients with WM/LPL.