Combined evaluation of conventional MRI, dynamic contrast-enhanced MRI and diffusion weighted imaging for response evaluation of patients with multiple myeloma

Purpose: To evaluate the value of the combined evaluation of SE MRI, dynamic contrast enhanced MRI (DCE-MRI) and diffusion weighted imaging (DWI) in multiple myeloma (MM) patients after treatment compared to the international myeloma working group (IMWG) response criteria.

Materials and methods: The retrospective study includes 27 newly diagnosed patients, providing 99 MRI-investigations. Patients were categorized according to the IMWG response criteria. Quantitative assessment was based on signal intensities (SI) of T1-weighted, fat-saturated T2-weighted and b1000 images, apparent diffusion coefficients (ADC) and parameters from time-intensity-curves (TIC) derived from L3. Qualitative visual analysis of conventional MRI-images, b1000-images and TICs, providing a "combined skeletal score", was used to create MRI response criteria.

Results: The combined skeletal score could significantly differentiate between subgroups based on IMWG response criteria (p=0.016). The gold standard plasmacytosis could significantly differentiate between subgroups based on MRI response criteria (p<0.001), as well as slope (p<0.001) and ADC (p=0.006). There is a good agreement between IMWG and MRI response criteria (Kendall's coefficient=0.761).

Conclusion: Response evaluation of MM-patients based on the combination of anatomical information from conventional MRI with functional information from DCE-MRI and DWI, is useful for monitoring therapy.