Comparison of technetium-99m-MIBI and technetium-99m-tetrofosmin uptake by musculoskeletal sarcomas

Technetium-99m-MIBI was initially developed for heart studies but it can also be used to depict tumors, predict multidrug resistance and evaluate chemotherapy. Recently, Tc-99m-tetrofosmin, which exhibits similar physical properties, has been launched for heart studies. Tumor uptake and prediction of multidrug resistance have also been reported regarding the latter tracer. A comparison of these two tracers regarding the detectability of musculoskeletal sarcoma has been made. Methods: Twenty patients with musculoskeletal sarcoma of the extremities or pelvis underwent planar examination after the administration of Tc-99m-MIBI and Tc-99m-tetrofosmin with an interval of 2-7 days. The tumor activity was compared with one ipsilateral and one contralateral background region. Results: There was a small, but not significant, difference in favor of Tc-99m-MIBI with regard to both background regions. Conclusion: Technetium-99m-MIBI and Tc-99m-tetrofosmin can both be used to visualize musculoskeletal sarcomas. The choice may depend on which agent is used routinely for myocardial studies in the laboratory.