Background: 18F-FDG PET/CT is an efficient modality to monitor minimal residual disease (MRD), detect extra-medullary disease, assess disease burden, and therapy response in multiple myeloma patients. Purpose: The aim of this study is to assess therapy response in MM patients using both Deauville scoring (DS) and metabolic volumetric parameters and detect their predictive value. Patients and methods: A total of 50 adult patients newly diagnosed with multiple myeloma (MM) were prospectively evaluated. Using DS and metabolic parameters for analysis of initial and interim FDG-PET/CT scans , and then their prognostic value was detected.
Results: No statistical significance was detected for DS either in initial or interim PET/CT studies. Regarding the metabolic parameters, initial metabolic tumor volume (MTV) and TLG between responder and non-responder categories showed notable significance with a p value of 0.004. Moreover, interim MTV, total lesion glycolysis (TLG) and SUVpeak determined p values of 0.021, 0.009, and 0.007, respectively. Conclusion: Metabolic volumetric parameters were promising tools to predict outcome in MM patients. The cutoff of initial MTV greater than 70 showed sensitivity of 78 % and specificity of 71.4%. The sensitivity of 56% and specificity of 93% for the cutoff of initial TLG more than 350. Interim SUVpeak level with a cutoff point of more than 3, showing sensitivity of 86% and specificity of 73%.