TI-201 CHLORIDE SPECT IMAGING OF HEPATOCELLULAR-CARCINOMA

Purpose: Tl-201 chloride has been used to image viable tumors in vario us sites of the body. There has been limited use of Tl-201 below the d iaphragm because of normal uptake in the liver, spleen, kidneys, and i ntestines. The use of sequential Tl-201 and Tc-99m sulfur colloid in t he detection and characterization of suspected hepatocellular carcinom a (HCC) was prospectively evaluated. Methods: Four patients with indet erminate liver nodules on radiologic imaging studies were studied with sequential Tl-201 and sulfur colloid liver scans on a triple-headed g amma camera with planar and SPECT acquisition. All patients had subseq uent pathologic correlation. Results: There were three focal nodular H CC lesions and one case of multicentric HCC, size varying between 1.9 cm and greater than 4.0 cm (multicentric HCC). In all lesions, Tl-201 SPECT images showed abnormal increased uptake at sites of HCC, which c orresponded to areas of photopenia on sulfur colloid. Computed tomogra phy detected a lesion in two of four patients, whereas US was positive in all patients. However, US was specific for tumor in only one patie nt and CT was not specific in any patient. Conclusion: We believe that in patients with suspected HCC, Tl-201 SPECT imaging will have an imp ortant role in the detection and characterization of HCC, especially i n the cirrhotic patient. Planar Tl-201 hepatic images will usually be normal, except in large lesions, and high-resolution SPECT technique i s essential in successful liver tumor imaging.