Head-to-head comparison between 18 F-DOPA PET/CT and 68 Ga-DOTA peptides PET/CT in detecting intestinal neuroendocrine tumours: A systematic review and meta-analysis.

PURPOSE: The imaging of intestinal neuroendocrine tumours (NETs) relies on functional positron emission tomography (PET) tracers; these tumours can be studied by means of both 68 Ga-DOTA peptides and 18 F-fluorodihydroxyphenyl- l-alanine (18 F-DOPA) PET/computed tomography (CT). As yet, it is unclear which of these two modalities offers the better sensitivity. We therefore conducted a meta-analysis to assess the available data. METHODS: PubMed, CENTRAL, Scopus and Web of Science were searched for studies comparing the sensitivity of 68 Ga-DOTA peptides and 18 F-DOPA PET/CT; papers up to February 2021 were considered. In each study, we considered sensitivity in terms of patient-based analysis (PBA), region-based analysis (RBA) and lesion-based analysis (LBA), and pooled the results yielded by each tracer. Multidisciplinary follow-up served as the standard of truth. RESULTS: Of the 636 records identified, 6 articles published between 2008 and 2021 were finally selected, and 112 intestinal NETs patients were included. The pooled sensitivity of 18 F-DOPA PET/CT was 83%, 89% and 95% on PBA, RBA and LBA, respectively. 68 Ga-DOTA peptides PET/CT showed sensitivity of 88%, 92% and 82% on PBA, RBA and LBA, respectively. No significant differences were found between the two tracers on PBA and RBA. By contrast, a clear trend towards significance in favour of 18 F-DOPA PET/CT was identified on LBA. The presence of a significant difference in favour of 18 F-DOPA PET/CT was confirmed in a subgroup analysis conducted only on the most recent and largest studies. In all three analyses, mild-to-high heterogeneity was found; however, no publication bias was observed. CONCLUSION: Both 18 F-DOPA PET/CT and 68 Ga-DOTA-peptides PET/CT are reliable diagnostic procedures in patients with intestinal NETs. However, in terms of lesion detection, a non-negligible difference in favour of 18 F-DOPA PET/CT was observed. Thus, the use of 18 F-DOPA PET/CT could be considered as a first-line molecular procedure in intestinal NETs.