Tc-99m MIBI scintigraphy in multiple myeloma: prognostic value of different Tc-99m MIBI uptake patterns.

PURPOSE

Technetium-99m 2 methoxyisobutylisonitrile (Tc-99m MIBI) scintigraphy has been used to identify biologic activity and extent of multiple myeloma (MM) and monoclonal gammopathy of unknown significance (MGUS). The examination could also serve both as a prognostic tool and an examination for monitoring the disease course in MM patients. The purpose of this study was to evaluate the prognostic value of different Tc-99m MIBI uptake patterns.

MATERIALS AND METHODS

Ninety-nine consecutive patients with newly diagnosed symptomatic MM and 18 patients with MGUS underwent baseline Tc-99m MIBI scintigraphy before applying any kind of therapy. The Tc-99m MIBI scans were classified as showing normal, diffuse, and focal or combined (diffuse and focal) patterns of tracer uptake. To evaluate the prognostic value of different Tc-99m MIBI uptake patterns, overall survival (OS) was chosen as an end point. Median of follow-up period was 84 months. Survival according to patterns of Tc-99m MIBI uptake was calculated using the Kaplan-Meier plots.

RESULTS

Statistically significant correlation between the baseline patterns of Tc-99m MIBI uptake and OS was found (P < 0.0001). Focal or combined patterns of Tc-99m MIBI uptake indicated significantly worse prognosis with shorter OS than normal or diffuse tracer patterns.

CONCLUSIONS

Tc-99m MIBI scintigraphy plays the predictive role in the follow-up of patients with MM. Baseline scintigraphic pattern of Tc-99m MIBI uptake seems to be a useful prognostic indicator of OS in MM patients and Tc-99m MIBI scintigraphy could be used as an additional tool for the initial examination in patients with newly diagnosed MM.