Aim: Our study aimed to investigate the role of qualitative and quantitative whole body MRI with DWI for assessment of bone marrow involvement (BMI) in newly diagnosed lymphoma using FDG PET-CT and bone marrow biopsy (BMB) as reference standard.
Materials and methods: We retrospectively evaluated 56 patients with newly diagnosed lymphoma (21 Hodgkin's lymphoma and 35 non-Hodgkin's lymphoma) who underwent random unilateral BMB, FDG PET-CT and Wb-MRI-DWI for initial staging. In a patient-based analysis, results of Wb-MRI-DWI were compared with FDG PET-CT and BMB. For quantitative analysis, mean ADC values of posterior iliac crest were correlated with BMI and bone marrow cellularity.
Results: WB-MR-DWI obtained excellent concordance with FDG PET-CT both in HL (k = 1.000; 95% CI 1.000-1.000) and in DLBCL (k = 1.000; 95% CI 1.000-1.000). In other NHL, WB-MRI-DWI obtained a good correlation with BMB (k = 0.611; 95% CI 0.295-0.927) while FDG PET-CT had poor concordance (k = 0.067; 95% CI 0.372-0.505). WB-MR-DWI has no false negative errors but 4 false positive results consisting in focal lesions consensually reported by FDG PET-CT and resolved after therapy. No significant correlation between ADC mean value and BMI was found (p = 0.0586).
Conclusion: Our data suggest that Wb-MRI-DWI is a valid technique for BMI assessment in lymphoma patients, thanks to its excellent concordance with FDG PET-CT and good concordance with BMB (superior than FDG PET-CT). If further investigations will confirm our results on larger patient groups, it could become a useful tool in the clinical workup.
Keywords: Bone marrow; Bone marrow biopsy; FDG PET–CT; Lymphoma; Whole body DWI; Whole body MRI.