Whole-body MRI for the detection of bone marrow involvement in lymphoma: prospective study in 116 patients and comparison with FDG-PET.

OBJECTIVE

To assess and compare the value of whole-body MRI with FDG-PET for detecting bone marrow involvement in lymphoma.

METHODS

A total of 116 patients with newly diagnosed lymphoma prospectively underwent whole-body MRI and blind bone marrow biopsy (BMB) of the posterior iliac crest. Of 116 patients, 80 also underwent FDG-PET. Patient-based sensitivities of whole-body MRI for detecting bone marrow involvement were calculated using BMB as reference standard and compared with FDG-PET in aggressive and indolent lymphomas separately.

RESULTS

Sensitivity of whole-body MRI in all lymphomas was 45.5 % [95 % confidence interval (CI): 29.8-62.0 %]. Sensitivity of whole-body MRI in aggressive lymphoma [88.9 % (95 % CI: 54.3-100 %)] was significantly higher (P = 0.0029) than that in indolent lymphoma [23.5 % (95 % CI: 9.1-47.8 %)]. Sensitivity of FDG-PET in aggressive lymphoma [83.3 % (95 % CI: 41.8-98.9 %)] was also significantly higher (P = 0.026) than that in indolent lymphoma [12.5 % (95 % CI: 0-49.2 %)]. There were no significant differences in sensitivity between whole-body MRI and FDG-PET (P = 1.00) CONCLUSION: Sensitivity of whole-body MRI for detecting lymphomatous bone marrow involvement is too low to (partially) replace BMB. Sensitivity of whole-body MRI is significantly higher in aggressive lymphoma than in indolent lymphoma and is equal to FDG-PET in both entities.

KEY POINTS

• Bone marrow involvement in lymphoma has prognostic and therapeutic implications. • Blind bone marrow biopsy (BMB) is standard for bone marrow assessment. • Neither whole-body MRI nor FDG-PET can yet replace BMB. • Both techniques have higher sensitivity in aggressive than in indolent lymphoma. • Both imaging techniques are complementary to BMB.