Theranostic Radiopharmaceuticals of Somatostatin Receptors for Patients with Neuroendocrine Tumors: Agonists Versus Antagonists—A Systematic Review and Meta-Analysis

Neuroendocrine tumors (NETs) are a rare and heterogeneous class of neoplastic lesions, but their prevalence has increased significantly over the past three decades. These tumors are aggressive and difficult to treat. Improving diagnostic efficiency and treatment effectiveness is important for patients with neuroendocrine tumors. Radiopharmaceutical therapeutic diagnostics combines diagnosis and treatment technology and has broad prospects in precision medicine, especially for the early diagnosis and treatment of tumors. To compare the diagnostic advantages of radiolabeled somatostatin receptor agonists and antagonists for liver metastases from NETs and the disease control rate in NET patients. Systematic search of PubMed, Embase, Cochrane, Ovid, Scopus, and Web of Science databases up to 29 October 2024. Clinical trials of somatostatin receptor agonists and antagonists for NET diagnosis or treatment. Following PRISMA guidelines, data were independently extracted by two researchers. Pooled diagnostic or treatment effects and 95% CIs were reported using a random-effects meta-analysis model. Effect of somatostatin receptor agonists and antagonists in detecting liver metastases and disease control rate. Risk Ratio (RR) for liver metastasis detection and Effect Size (ES) for disease control rate were calculated. From 5291 articles, 52 were included in the meta-analysis. Radiolabeled somatostatin receptor antagonists were significantly more effective than agonists in detecting liver lesions (RR = 11.57, 95% CI: 4.10, 32.67). Disease control rates were higher with antagonists (ES = 0.90, 95% CI: 0.83, 0.96) compared to agonists (ES = 0.82, 95% CI: 0.78, 0.85, z = 2.12, p = 0.03). Radiolabeled somatostatin receptor antagonists outperform agonists in diagnosing hepatic lesions and controlling disease in NETs, highlighting their clinical superiority. This meta-analysis provides critical insights into the diagnostic and therapeutic efficacy of somatostatin receptor antagonists, and may offer a potential paradigm shift in the management of neuroendocrine tumors. Nevertheless, the smaller number of studies on antagonists may limit the generalizability of the findings and underscore the need for further clinical trials to validate these results.