Prognostic value of semi-quantitative parameters of ¹⁸F-FDG PET/CT in newly diagnosed multiple myeloma patients

To investigate the prognostic value of fluroine-18 fluorodexyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) semi-quantitative parameter in newly diagnosed multiple myeloma (NDMM) and to design a new staging system including ¹⁸F-FDG PET/CT semi-quantitative parameters for NDMM.

A total of 38 NDMM patients who underwent ¹⁸F-FDG PET/CT examination in Yichang Central People's Hospital from February 2014 to April 2021 were collected. The relationship between the characteristics of ¹⁸F-FDG PET/CT (metabolic tumor volume of all lesions (aMTV), total lesion glycolysis of all lesions (aTLG), maximum standardized uptake values (SUVmax) of the lesion with largest MTV (mSUVmax), extramedullary disease (EMD), focal lesions (FLs)), the laboratory parameters, and prognostic parameters (progression-free survival (PFS) and overall survival (OS)) were analyzed retrospectively. SPSS 25.0 statistical software was used for statistical processing, Kaplan-Meier method was used for survival analysis, Log-rank method was used for univariate analysis, and Cox proportional risk model was used for multivariate analysis.

Univariate analysis showed that aMTV ≥ 90.97cm³, aTLG ≥ 283.31 g, hemoglobin (Hb) < 100 g/L, focal lesions (FLs) ≥ 10, (percentage of circulating plasma cells (CPC%) ≥ 30%, creatinine (Cr) ≥ 177umol/L, lactic dehydrogenase (LDH) ≥ 250 g/L might be the adverse prognostic factors of PFS in patients with NDMM, all p < 0.05; aMTV ≥ 90.97 cm³, aTLG ≥ 283.31 g, Hb < 100 g/L, FLs ≥ 10, mSUVmax ≥ 5.8, the presence of extramedullary disease (EMD) and PCPs ≥ 30% may be adverse prognostic factors for OS in patients with NDMM, all p < 0.05. Multivariate regression analysis showed that aMTV ≥ 90.97 cm³ was an independent risk factor for PFS in NDMM patients, p < 0.05; aMTV ≥ 90.97 cm³, mSUVmax ≥ 5.8, and the presence of EMD were independent risk factors for OS in the NDMM patients, all p < 0.05. According to the multivariate analysis results of OS, the New stage (NS) was performed. The 3-year OS rates of stage I, stage II, and stage III in NDMM patients were 100.0, 53.5, and 32.1%, respectively, p = 0.000.

aMTV can predict PFS and OS of NDMM patients better than other parameters. NS which combined with aMTV can predict OS of NDMM patients better and can provide an accurate and simple method for risk stratification of NDMM patients.