Prognostic significance of focal lesions and diffuse infiltration on MRI for multiple myeloma: a meta-analysis

Objectives: MRI of bone marrow of the axial skeleton is recommended for evaluation of multiple myeloma. The impact of bone marrow involvement pattern on MRI for determining progression-free survival (PFS) and overall survival (OS) is not yet clear. Methods: We performed a meta-analysis of research on the prognostic significance of MRI patterns for OS and PFS using a random effects model. Databases searched without language restriction were MEDLINE, EMBASE, and the Cochrane Library (January 1976 to April 2014). Manual searches were also conducted. Results: Of 10,953 citations identified in the original search, 10 cohort studies for a total of 2015 patients met the inclusion criteria. Nine of the 10 included studies are from three research groups. Pooled hazard ratios were 1.80 (95 % confidence interval [CI] 1.32–2.46; P < 0.001) for OS and 2.30 (95 % CI 1.65–3.20; P < 0.001) for PFS for focal lesions on MRI; and 1.70 (95 % CI 1.30–2.21; P < 0.001) for OS and 1.74 (95 % CI 1.07–2.85; P = 0.03) for PFS for diffuse infiltration on MRI. No significant heterogeneity was observed among studies. Conclusions: This meta-analysis demonstrated an association between focal lesions and diffuse infiltration and poor prognosis in this population. Key Points: • MRI findings of multiple myeloma include normal, focal, variegated and diffuse infiltration • Focal lesions and diffuse infiltration on MRI were poor prognostic factors • Bone marrow involvement pattern on MRI can help physicians assess prognosis.