PET/CT seems to add value to conventional imaging in the initial staging of patients with T2-4 disease but further high-quality research is required to validate this. There is insufficient evidence at this time to recommend a routine use of PET/CT in the assessment of treatment response or follow-up. Advances in knowledge: PET/CT appears to alter the disease stage and management in a meaningful number of patients to justify its use as part of staging investigations in locally advanced cases.

Purpose The aim of this study was to systematically review the literature to assess the role of 68Ga PET imaging in neuroendocrine tumors (NETs). Materials and Methods The literature was searched using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews databases through OVID. Studies comparing PET or PET/CT with conventional imaging in the initial diagnosis, staging and restaging, assessment of treatment response, and routine surveillance of NETs were deemed eligible for inclusion. Risk of bias and applicability concerns were assessed using the Quality Assessment of Diagnostic Accuracy Studies tool. Results Twenty-two studies met the inclusion criteria. For the initial diagnosis of NETs, PET or PET/CT had a pooled sensitivity of 91% (95% confidence interval [CI], 85%–94%) and a pooled specificity of 94% (95% CI, 86%–98%). In the setting of staging and restaging, the sensitivity of PET or PET/CT for detecting primary and/or metastatic lesions ranged from 78.3% to 100%, whereas specificity ranged from 83% to 100%. Change in management occurred in 45% (95% CI, 36%–55%) of the cases, with majority of the changes involving surgical planning and patient selection for peptide receptor radionuclide therapy. Conclusions 68Ga PET or PET/CT is recommended for initial diagnosis where conventional testing remained equivocal, for staging of patients with localized primary and/or limited metastasis where definitive surgery is planned, to determine somatostatin receptor status and suitability for peptide receptor radionuclide therapy, and for staging of patients where detection of occult disease will alter treatment options and decision making.