Whole-body MRI and PET/CT in multiple myeloma patients during staging and after treatment: personal experience in a longitudinal study

Diagnostic imaging plays a pivotal role in staging and prognostic assessment of multiple myeloma (MM) as well as planning and monitoring treatment. The aim of our study was to estimate the diagnostic accuracy of wholebody magnetic resonance imaging (WB-MRI) and positron emission tomography/computed tomography (PET/CT) in MM patients studied before and after treatment. We considered 22 consecutive patients (10 males, 12 females; age range, 48-83 years) with newly diagnosed MM (NDMM group), and the same 22 patients underwent at least one re-assessment after treatment (previously treated MM, PTMM group). WBMRI and PET/CT were performed within days from each other in both the NDMM (22 studies) and PTMM (29 studies) group. The imaging findings were compared to the results of bone marrow aspiration. PET/CT was positive in 18/22 NDMM patients, whereas WB-MRI correctly identified 100% of patients. Of 20 responder patients in the PTMM group, 16 were negative at PET/CT and 12/20 at MRI. By contrast, of the nine nonresponder patients, MRI correctly detected active disease in all cases, and PET only in seven. WB-MRI proved superior to PET/CT in detecting MM, especially in diffuse disease. PET/CT appears to be more sensitive in the assessment of MM after treatment.