2016 IMWG criteria state that detection of bone lesions is essential for diagnosis of MM, and PET/TC is one of the techniques essential for detecting the presence of bone disease. Whole-body MRI ...(WB-MRI) is a cross-sectional imaging technique for the entire skeletal study with the advantage of higher soft-tissue contrast, offering the opportunity to also visualize bone marrow appearance.
The integration of fluorodeoxyglucose-positron emission tomography (FDG-PET)/TC and WB-MRI in MM may result in higher accuracy to detect bone lesions compared to FDGPET/TC alone. This could be translated into better outcomes if early detection of myeloma defining events leads to earlier induction or re-induction treatments.
In our institution, from January 2021 to January 2023, we performed a prospective trial enrolling 73 consecutive newly diagnosed and relapsed/refractory MM patients (median age 63 years - range 85-35), according to IMWG, in which WB-MRI was performed according to MY-RADS criteria in combination with FDG PET/CT. 31/73 (42%) had a newly diagnosed MM, 25/73 (34%) were in follow-up after ASCT and 17/73 (23%) patients were affected by relapsed/refractory MM. Subsequently, in 2 cases WB-MRI were aborted and not diagnostic so patients were excluded from the final analysis.
In these 71 patients: 52/71 (73%) of concordance of WB-MRI and 18F PET-CT, 18/71 (25%) of discordance. In this group 15/18 (83%) cases FDG-PET/CT was negative and WB-MRI showed positive findings according to MYRADS criteria (5 micronodular pattern, 9 diffuse pattern e 1 focal pattern), in 3/18 (17%) FDG-PET/CT was positive for focal lesions and WB-MRI was negative. IMWG criteria showed concordance with WB-MRI data in 16/18 (89%). In 2/18 (11%) cases of follow-up after ASCT, PET-CT showed a relapsed focal lesion while WB-MRI was negative. Accuracy of WB-MRI was 69/71 (97%), whilst PET-CT was 55/71 (77%).
Our preliminary results support a potential complementary role of WB-MRI and FDG PET/CT, on the management of patients with MM at both diagnosis and relapse. To date, there is no wide availability of WB-MRI because of concern about costs and technical issues, but data are consistent with its possible future leading role.
