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

Background. The aim of this study is to evaluate the usefulness of thallium-201 (TI-201) single-photon emission CT (SPECT) to detect recurrent or residual nasopharyngeal carcinomas (NPC) when CT findings are indeterminate. Methods. After radiotherapy, 30 NPC patients with indeterminate CT findings were included. CT, TI-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. Results. The rates for sensitivity, specificity, and accuracy of TI-201 SPECT in detecting recurrent or residual NPC when there were indeterminate CT findings, were 86.7%, 93.3%, and 90.0%, respectively. Conclusions. These results suggest that TI-201 SPECT is effective in detecting recurrent or residual NPC when CT findings are indeterminate. (C) 2003 Wiley Periodicals, Inc.