Using thallium-201 SPECT to detect recurrent or residual nasopharyngeal carcinoma after radiotherapy in patients with indeterminate CT findings.

Abstract

The aim of this study is to evaluate the usefulness of thallium-201 (Tl-201) single-photon emission CT (SPECT) to detect recurrent or residual nasopharyngeal carcinomas (NPC) when CT findings are indeterminate. After radiotherapy, 30 NPC patients with indeterminate CT findings were included. CT, Tl-201, and biopsy were performed at least 4 months after radiotherapy and within 1 week of each other. The final results were based on histopathologic findings and clinical follow-up after at least 6 months. The rates for sensitivity, specificity, and accuracy of Tl-201 SPECT in detecting recurrent or residual NPC when there were indeterminate CT findings, were 86.7%, 93.3%, and 90.0%, respectively. These results suggest that Tl-201 SPECT is effective in detecting recurrent or residual NPC when CT findings are indeterminate.