Fluorodeoxyglucose-avid focal lesions and extramedullary disease on 18F-FDG PET/computed tomography predict the outcomes of newly diagnosed symptomatic multiple myeloma patients

To investigate whether the number of fluorodeoxyglucose (FDG)-avid focal lesions and the presence of extramedullary disease (EMD) on F-FDG PET/computed tomography (PET/CT) can predict the outcomes of newly diagnosed symptomatic multiple myeloma patients.We performed a meta-analysis to research the prognostic significance of focal lesions and EMD on F-FDG PET/CT for overall survival (OS) and progression-free survival (PFS) using a fix-effected model. The PubMed, EMBASE and Cochrane Library databases were searched. Manual searches were also conducted.Of the 398 citations identified in the original search, 13 original studies with a total of 2823 patients met the inclusion criteria. The pooled hazard ratios of focal lesions were 1.63 [95% confidence interval (CI) 1.41-1.86, P = 0.442, I= 0%] for PFS and 2.15 (95% CI 1.74-2.57, P = 0.615, I= 0%) for OS. The pooled hazard ratios of EMD were 1.89 (95% CI 1.44-2.34, P = 0.497, I= 0%) for PFS and 1.91 (95% CI 1.08-2.73, P = 0.182, I= 29.6%) for OS. The results of the subgroup analysis showed the same trend. No significant heterogeneity was observed among studies.This meta-analysis demonstrated that patients with a higher number of FDG-avid focal lesions and EMD on PET/CT may experience a higher risk for progression and a shorter survival time than those with a few focal lesions and no EMD.