Prognostic Value of Baseline 18F-Fluorodeoxyglucose PET/CT in Patients with Multiple Myeloma: A Multicenter Cohort Study.

Objective: We investigated the prognostic value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in patients with multiple myeloma (MM). Materials and

Methods: Subjects were 76 patients with newly diagnosed myeloma and pretreatment with 18F-FDG PET/CT from four hospitals. The PET/CT features were evaluated and the clinical characteristics were reviewed. Prognostic factors related to poor progression-free survival (PFS) and overall survival (OS) were identified using a Cox proportional hazards regression model and a prediction scale was developed based on the identified factors.

Results: Multivariate analysis showed that the presence of 18F-FDG-avid focal bone lesions (≥ 3) was a significant and independent predictor of PFS (hazard ratio [HR] = 3.28, p = 0.007) and OS (HR = 11.78, p = 0.001). The presence of extramedullary disease on PET/CT scan was also a significant predictor of poor PFS (HR = 2.79, p = 0.006) and OS (HR = 3.89, p = 0.003). A prognostic scale was developed using these two predictors. An increase in score on the scale corresponded to a significantly increased risk of poor OS (p = 0.005). In addition, Kaplan-Meier analysis demonstrated that patient survival varied significantly according to the scale (p < 0.001 for OS and p = 0.001 for PFS).

Conclusion: 18F-FDG-avid focal lesions and the presence of extramedullary disease on PET/CT scan are significantly associated with poor OS in MM patients. The scale developed according to these predictors represents a potential prognostic tool for evaluation of patients with MM.