Scintigraphy using (99m)Tc-MIBI (sestamibi), a sensitive parameter of activity of multiple myeloma.

Technetium-99m methoxyisobutylisonitrile ((99m)Tc-MIBI) has been shown to be useful in identifying several types of tumors, such as breast, brain, thyroid gland, malignant lymphomas and multiple myeloma. In this study, 102 patients with multiple myeloma (MM) and 32 patients with monoclonal gammopathy of undetermined significance (MGUS) had been evaluated for correlation between (99m)Tc-MIBI and biochemical and hematological markers of activity of the disease. Significant statistical correlation was found between summary score (SS) of (99m)Tc-MIBI scintigrams and beta2-microglobulin (p<0.001), monoclonal immunoglobulin level MIG (p<0.001), serum thymidinekinase - sTK (p<0.001), CRP (p<0.05) and cross-linked carboxyterminal telopeptide of type I collagen - ICTP (p<0.05) bone marrow plasmocytosis-BMPc (p<0.001) and hemoglobin Hb (p<0.001). All 32 patients with MGUS had physiological activity of (99m)Tc-MIBI scintigrams. Technetium-99m methoxyisobutylisonitrile is a useful indicator of activity of MM and helps in differentiating between multiple myeloma and monoclonal gammopathy of undetermined significance.