Clinical impact of spine magnetic resonance imaging as a valuable prognostic tool for patients with multiple myeloma: a retrospective study

Background: This study investigated the prognostic impact of spine magnetic resonance imaging (MRI) in patients newly diagnosed with multiple myeloma (MM). Methods: We retrospectively evaluated 214 patients who were newly diagnosed with MM between March 2015 and December 2019. The patients were classified into five different infiltration patterns based on spine MRI as follows: (1) normal appearance, (2) focal, (3) diffuse, (4) combined focal and diffuse infiltration, and (5) "salt-and-pepper." Results: Forty patients (18.7%) showed a normal appearance, whereas focal, diffuse, combined focal and diffuse infiltration, and "salt-and-pepper" patterns were identified in 68 (31.8%), 40 (18.7%), 52 (24.3%), and 14 patients (6.5%), respectively. The patients with normal and "salt-and-pepper" patterns were younger than patients with other patterns (median age, 61.6 vs. 66.8 years; p=0.001). Moreover, 63% and 59.3% of patients with normal and "salt-and-pepper" patterns were scored International Staging System (ISS) stage I and revised ISS (R-ISS) stage I, respectively, whereas only 12.5% of patients with other patterns were scored ISS stage I and R-ISS stage I. Patients with normal and "salt-and-pepper" patterns had a better prognosis than those with other patterns, whereas relapse and death rates were significantly higher in patients with focal, diffuse, and combined MRI patterns. Conclusion: Characteristic MRI findings have a significant prognostic value for long-term survival in patients newly diagnosed with MM. In particular, focal, diffuse, and combined focal and diffuse infiltration patterns are unfavorable prognostic factors.