18F-FDG-PET and 18F-FDG-PET/CT in the detection of recurrent or metastatic medullary thyroid carcinoma: A systematic review and meta-analysis

The aim of this study was to investigate diagnostic performance of 18F-fluorodeoxyglucose position emission tomography (FDG-PET) and PET/computed tomography (PET/CT) for detection of recurrent or metastatic medullary thyroid carcinoma (MTC) in patients after surgery with a meta-analysis. MEDLINE and EMBASE databases were searched for relevant articles. Two investigators independently extracted the data about study characteristics and examination results. Pooled estimates of sensitivity of FDG-PET or FDG-PET/CT were obtained. Fifteen studies met all inclusion criteria. The sensitivity of FDG-PET ranged from 0.47 (95% confidence intervals (CI): 0.210.73) to 0.96 (95%CI: 0.860.99), the sensitivity of FDG-PET/CT ranger from 0.47 (95% CI: 0.310.64) to 0.80 (95% CI: 0.650.90). The pooled sensitivities of FDG-PET and PET/CT were 0.68 (95% CI: 0.640.72) and 0.69 (95% CI: 0.640.74), respectively. There was no statistic significant between FDG-PET and PET/CT. Our results indicate that FDG-PET or FDG-PET/CT has reasonable sensitivity in detecting recurrent or metastatic MTC after primary surgery. However, no single diagnostic technique is able to reliably demonstrate the full extent of disease in patients with recurrent or metastatic MTC, the combination of cross-sectional radiography with FDG-PET or PET/CT is recommended.