F-FDG PET/CT is useful for determining survival outcomes of patients with multiple myeloma classified as stage II and III with the Revised International Staging System.

Purpose: This study evaluated the prognostic role of F-FDG PET/CT at baseline in patients with newly diagnosed multiple myeloa (MM) and evaluated the prognostic relevance of F-FDG PET/CT for each stage according to the Revised International Staging System (R-ISS).

Method: We retrospectively analyzed the records of 167 patients with newly diagnosed MM. F-FDG PET/CT was performed prior to induction therapy in patients with newly diagnosed MM.

Results: In the total cohort, the presence of more than three hypermetabolic focal lesions (FLs) or extramedullary disease (EMD) on baseline PET/CT was associated with significantly inferior progression-free survival (PFS) and overall survival (OS) than other patients. Because most patients (91%) with EMD had more than three FLs, PET/CT positivity was defined as the presence of more than three FLs or the presence of EMD. In multivariate analyses, PET/CT positivity was an independent predictor of PFS and OS in all patients. Fifty-five patients (46.1%) with R-ISS II were PET/CT-positive at baseline and had significantly shorter PFS and OS. PET/CT positivity was also correlated with poor PFS and OS in patients with R-ISS III.

Conclusion: F-FDG PET/CT was an independent predictor of survival outcomes in patients with newly diagnosed MM. In addition, performing F- FDG PET/CT at diagnosis may be useful for determining the survival outcomes of MM patients with R-ISS II and III.