Background: The ability of 68Ga-DOTA-SSTR to detect the primary sites of neuroendocrine tumors (NETs) remains undetermined, and the clinical benefit of this imaging agent is not clear.
Purpose: To evaluate the diagnostic accuracy of 68Ga-DOTA-SSTR for carcinoma unknown primary (CUP) neuroendocrine tumors and to further analyze the detection rate of 68Ga-DOTA-SSTR for primary and metastatic sites.
Material and methods: A comprehensive literature search of PubMed/MEDLINE and ScienceDirect was performed in October 2019 in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. We critically reviewed all studies based on the PICOS criteria. QUADAS-2 was used to evaluate the quality of the methodology of the included studies.
Results: A total of 10 studies (484 patients, mean age = 56.6 ± 4.3 years) were included in the study. The pooled sensitivity and specificity of 68Ga-DOTA-SSTR in identifying CUP-NETs were 82% and 55%, respectively. The area under the receiver operating characteristic curve was 69%. Regarding metastasis sites, 68Ga-DOTA-SSTR found the most metastases in the liver (57.9%), followed by the lymph nodes (22.8%), bones (12.8%), lung (2.8%), and others (1.7%). The pooled detection rate of 68Ga-DOTA-SSTR for CUP-NETs was 61%.
Conclusion: The present study demonstrated the high diagnostic sensitivity of 68Ga-DOTA-SSTR for CUP-NETs. 68Ga-DOTA-SSTR PET/CT was highly effective in locating the primary and metastatic sites of CUP-NETs.
Keywords: 68Ga-DOTA-somatostatin receptor; Meta-analysis; carcinoma unknown primary; computed tomography; neuroendocrine tumors; positron emission tomography.