Comparative SPECT Findings of Tc-99m Depreotide, Tc-99m Tetrofosmin, and TI-201 Chloride for Bronchogenic Carcinoma

A large area of uptake with central photon deficiency was coincidentally demonstrated on raw data cine of the TI-201 chloride image in the right lower lung but was not identified by the concurrent raw data cine of the Tc-99m tetrofosmin image on dual-isotope gated myocardial SPECT. This mass was also shown on Tc-99m depreotide SPECT with a central photon deficiency in the right lower lung. These findings corresponded to an 8 × 6 cm mass with central necrosis in the right lower lung posteriorly on a computed tomographic (CT) scan. A CT-guided needle biopsy of the tumor confirmed squamous cell carcinoma. In this patient, although Tc-99m tetrofosmin yielded a false-negative result, TI-201 chloride and Tc-99m depreotide SPECT findings reflected a mass lesion with central necrosis.