Prognostic value of vertebral lesions detected by magnetic resonance imaging in patients with stage I multiple myeloma

We assessed the role of spinal magnetic resonance imaging (MRI) and bone densitometry as prognostic factors in patients with asymptomatic stage I multiple myeloma (MM) and negative skeletal survey. 55 consecutive patients underwent spinal MRI and 41 of them underwent bone densitometry by dual-energy X-ray absorptiometry (DEXA). Spinal MRI studies showed evidence of bone marrow involvement in 17/55 patients (31%). A diffuse pattern was present in three patients and a focal pattern in 14 patients, nine of them with only one nodular lesion. During a median follow-up of 25 months, 10 patients had disease progression, 8/17 patients with abnormal MRI and 2/38 patients with normal MRI. Median time to disease progression was not reached in both groups but was significantly different for patients with normal and those with abnormal patterns on MRI (P < 0.0001). Lumbar BMD was only slightly decreased compared with normal people (median lumbar Z score -0.43) and was not of prognostic value. Using a multivariate analysis the only two independent significant prognostic parameters were abnormal MRI (P<0.001, HR 30.4, 95% CI 4.3-213) and bone marrow plasmacytosis >20% (P=0.004, HR 16.4, 95% Cl 2.6-104). Thus, spinal MRI but not bone densitometry, appeared to be justified in patients with stage I asymptomatic MM and negative skeletal survey.