Clinical and Prognostic Relevance of Magnetic Resonance Imaging of the Spine in Newly Diagnosed Multiple Myeloma Patients Receiving Autologous Stem Cell Transplantation.

Abstract 4885

Magnetic resonance imaging (MRI) of the spine has demonstrated to be a useful tool for a correct staging of multiple myeloma (MM), as it is more sensitive than plain x-rays in detecting vertebral lesions. Furthermore, both pattern of bone marrow involvement (focal, diffuse or normal), and number of focal lesions can be detected, and this could contribute to better define the prognosis and the outcome of newly diagnosed patients. In the present study we prospectively evaluated the clinical and prognostic role of spinal MRI in 152 newly diagnosed MM patients (89M, 63F, median age = 56yrs) that subsequently received high-dose chemotherapy and autologous stem cell transplantion, either single (n=43) or double (n=109). Pattern of marrow involvement was normal in 11% of the cases, diffuse in 20% and focal in 69%, with 34% of the patients showing > 7 focal lesions. Patients with a diffuse pattern or a focal pattern with > 7 lesions showed a significantly higher bone marrow plasma cell infiltration (p=0.04) and beta2 microglobulin values (p= 0.04) as compared to patients with a focal pattern with < 7 lesions. Response rate to the assigned treatment program was similar in the three groups of patients, with > VGPR obtained in 63% of the patients with a diffuse pattern, and in 70% of those with a focal pattern. Median progression-free survival (PFS) was significantly longer in patients with < 7 focal lesions as compared to those with >7 lesions or a diffuse pattern (55 vs 46 months p=0.05). Normalization of MRI was more frequently obtained in patients with < 7 lesions (67% vs 38% in patients with > 7 lesions, p=0.005); patients achieving a normal MRI pattern showed a significantly longer PFS (67 months) as compared to patients failing to achieve a negative MRI at the end of treatment (p=0.0000). According to our data, MRI confirms its prognostic role in newly diagnosed MM receiving high-dose therapy and autologous stem-cell transplantation; a diffuse pattern of bone marrow involvement or a focal pattern with > 7 lesions are predictive of a more aggressive outcome of the disease; furthermore normalization of MRI pattern after therapy is predictive of a longer progression-free survival