Detection of bone marrow malignancy by Tc-99m-MIBI bone marrow imaging

To investigate the usefulness of Tc-99m-methoxyisobutylisonitril (MIBI) in the detection of bone marrow malignancy, the affinity of MIBI to bone marrow was examined. A Fischer rat F344 (male, 8-weeks old) was used as the experimental animal, and the uptake of MIBI, Tc-99m-MDP and Tl-201 in the femur was measured. The uptake of MIBI was higher than those of Tl-201 and MDP. In patients with hypertension and coronary artery diseases showing normal bone marrow, the uptake of MIBI in the femur, the humerus, the breast bone and the thoracic vertebra was measured. No abnormal uptake was found in all patients. In patients with acute leukemia or metastatic bone tumors, who were diagnosed and suspected the bone marrow malignancy, the MIBI bone marrow scintigraphy was performed. Tumor lesions were detected with high accuracy by the MIBI bone marrow imaging. It is suggested that the MIBI bone marrow imaging is one of the useful modality in the diagnosis of bone marrow malignancy, the evaluation of the tumor volume and the decision of the therapeutic gain. In acute leukemia, this method makes it easy to detect the minimal residual disease and is useful to predict the recurrence and to evaluate the remission rate. In metastatic bone tumors, it makes possible to detect metastatic lesion at early stages. (K.H.)