Prognostic Impact of Metabolic Heterogeneity in Patients With Newly Diagnosed Multiple Myeloma Using 18F-FDG PET/CT

Purpose This study aimed to investigate the prognostic impact of metabolic heterogeneity (MH) in patients with multiple myeloma (MM). Patients and Methods We retrospectively analyzed MH with 18 F-FDG PET/CT in 203 patients with newly diagnosed MM. Metabolic heterogeneity was estimated using the area under the curve of the cumulative SUV volume histogram. To evaluate MH, we selected 2 lesions: “MH-SUV max ,” a lesion with SUV max , and “MH–metabolic tumor volume (MTV),” a lesion with the largest MTV. Results Metabolic heterogeneity from an MH-SUV max lesion showed more prognostic relevance than that from a lesion with the largest MTV. The progression-free survival (PFS) and overall survival (OS) rates were significantly lower in the high-MH-SUV max group than in the low-MH-SUV max group (median PFS: 25.2 vs 33.9 months; median OS: 41.6 vs 112.0 months; P = 0.004 and 0.046, respectively), whereas high MH-SUV max retained independent prognostic power on multivariate analysis. Even among patients with high whole-body MTV, those with high MH-SUV max tended to show poorer prognosis than those without (median PFS, 23.8 vs 30.2 months; P = 0.085). Moreover, patients with high MH-SUV max and high-risk cytogenetic abnormalities showed dismal outcomes even with standard treatment (median PFS and OS, 10.0 and 33.3 months, respectively). Conclusions Our results suggested that high MH-SUV max based on pretreatment with 18 F-FDG PET/CT is a novel prognostic factor for cases of MM.