FDG PET/CT versus somatostatin receptor PET/CT in TENIS syndrome: a systematic review and meta-analysis

Purpose In patients with TENIS syndrome (Thyroglobulin-Elevated Negative Iodine Scintigraphy), PET/CT radiotracers, such FDG PET/CT and somatostatin analogs (SSTR PET/CT), can identify disease localization. Therefore, the objective of this paper is to compare the capability of identifying lesions in TENIS Syndrome using FDG PET/CT and SSTR PET/CT through a systematic review and meta-analysis. Methodology A literature search was performed in electronic databases until February 2020 to identify relevant studies on FDG and 68 Ga-somatostatin analogs tracers in patients with TENIS Syndrome. Results A total of 3551 abstracts reviewed from electronic databases and bibliographic references identified 13 candidates for the full-text analysis, and six articles were included in the qualitative and quantitative analyses. A total of 179 patients submitted to both SSTR PET/CT and FDG PET/CT to evaluate the performance of these radiotracers were analyzed. FDG PET/CT images identified significantly ( p = 0.006) more patients with metastases when compared to SSTR PET/CT (143 vs. 103, respectively). Even though FDG PET/CT outperformed SSTR PET/CT, SSTR PET/CT was able to detect metastases in approximately 16% of FDG PET/CT negative cases. Conclusion FDG PET/CT has a higher capability to detect metastases than SSTR PET/CT in patients with TENIS Syndrome.