Diagnostic performance of PET in thyroid cancer with elevated anti-Tg Ab

We aimed to explore the role of the diagnostic accuracy of F-18 fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) for the detection of recurrent and/or metastatic diseases in differentiated thyroid cancer (DTC) patients with progressively and/or persistently elevated TgAb levels and negative radioactive iodine whole-body scan (RI-WBS) through a systematic review and meta-analysis. The MEDLINE, EMBASE and Cochrane Library database, from the earliest available date of indexing through June 30, 2017, were searched for studies evaluating the diagnostic performance of F-18 FDG PET/CT for the detection of recurrent and/or metastatic diseases in DTC patients with progressively and/or persistently elevated TgAb levels and negative RI-WBS. We determined the sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR+ and LR-). Across 9 studies (515 patients), the pooled sensitivity for F-18 FDG PET/CT was 0.84 (95% CI; 0.77-0.89) a pooled specificity of 0.78 (95% CI; 0.67-0.86). Likelihood ratio (LR) syntheses gave an overall positive likelihood ratio (LR+) of 3.8 (95% CI; 2.5-5.7) and negative likelihood ratio (LR-) of 0.21 (95% CI; 0.14-0.30). The pooled diagnostic odds ratio (DOR) was 18 (95% CI; 10-34). The area (AUC) under the hierarchical summary receiver-operating characteristic (HCROC) curve was 0.88 (95% CI: 0.85-0.90). F-18 FDG PET or PET/CT demonstrated moderate sensitivity and specificity for the detection of recurrent and/or metastatic diseases in DTC patients with progressively and/or persistently elevated TgAb levels and negative RI-WBS.