Quantitative assessment of tumor burden in multiple myeloma using MY-RADS from whole-body MRI: comparison with established prognostic biomarkers.

Abstract

Background: To explore the value of MY-RADS from whole-body MRI in assessing tumor burden in MM with reference to established prognostic biomarkers.

Methods: 108 consecutive newly diagnosed MM patients were retrospectively enrolled. Bone marrow (BM) infiltration patterns were determined by MRI presentation. The whole-body total burden score using MY-RADS, apparent diffusion coefficient (ADC), and fat fraction (FF) of representative background BM were measured. Spearman correlation analysis was used for correlating these parameters against plasma cell infiltration ratio, and independent sample t-test was used to evaluate the differences between different International Staging System (ISS) and free light-chain ratio groups.

Results: For diffuse, salt-and-pepper and normal patterns, patients with advanced ISS stage and high FLC-ratio had markedly lower FF and higher ADC of representative background BM. They also correlated well with plasma cell infiltration ratio. In contrast, the total burden score did not show significant difference between groups. For focal pattern, there was no significant difference of ADC and FF between groups. They didn't correlate with plasma cell infiltration ratio as well. While, patients with advanced ISS stage and high FLC-ratio had markedly higher MY-RADS total burden score and correlated well with plasma cell infiltration ratio. For mixed pattern, ADC for L3, FF for L3 and the total burden score all showed statistical difference and correlated well with plasma cell infiltration ratio.

Conclusion: The present study supports the applicability of MY-RADS as a surrogate biomarker when established prognostic biomarkers were not accessible conveniently.