Ferumoxtran-10-enhanced MR imaging of the bone marrow before and after conditioning therapy in patients with non-Hodgkin lymphomas

To quantify permeability changes of the "blood-bone marrow barrier" (BMB) and to detect malignant bone marrow infiltrations before and after conditioning therapy for subsequent leukapheresis using ferumoxtran-10-enhanced magnetic resonance (MR) imaging. Twenty-two patients with malignant non-Hodgkin lymphomas (NHL), including 9 patients (group A) before and 13 patients (group B) after conditioning therapy, underwent MR of the spine before and after infusion of ferumoxtran-10 (0.045 mmol Fe/kg BW). Pulse sequences comprised dynamic T1-GE and pre- and post-contrast T1-SE and STIR sequences. Dynamic δSI-data were correlated with the quantity of mobilized CD34+ cells. In addition, the number of focal bone marrow lesions was compared before and after ferumoxtran-10 administration. Dynamic δSI-data were higher in group B than in group A, indicating an increased BMB permeability after conditioning therapy. However, δSI-data did not correlate with the quantity of mobilized CD34+ cells. Ferumoxtran-10-enhanced STIR images demonstrated a significant signal decline of the normal, non-neoplastic bone marrow and a significantly increased detection of focal neoplastic lesions compared to pre-contrast images (P<0.05). Ferumoxtran-10 depicted the bone marrow response to conditioning therapy by an increase in BMB-permeability, which, however, did not correlate with the number of mobilized CD34+ cells. Ferumoxtran-10 improved the detection of focal bone marrow lesions significantly (P<0.05).