Theranostics and Precision Medicine in Neuroendocrine Tumors

Introduction. Neuroendocrine tumors (NETs) have increased expression of somatostatin receptors (SSTR), where subtype 2 and 5 are the most common. Overexpression of the SSTR is an outstanding molecular target for inoperable and metastatic NETs that enables a unique approach of targeted diagnosis and treatment. In addition to SSTRs, neuroendocrine tumors also express other receptors that can be suitable targets for visualization by nuclear medicine methods. Aim. This review paper is focused on the most common radiopharmaceuticals and their molecular targets that are used today based on theranostic approach in NETs.Results. In conventional nuclear medicine, the most important diagnostic radiopharmaceuticals are somatostatin analogs (SSA) labeled with 111In and 99mTc, however 99mTc has advantages over 111In based on better physical characteristics and better performance. In recent years, highly potent theranostic pairs have been created for the imaging and treatment of NETs, which can strongly bind SSTR. Derivatives of 68Ga-labeled octreotide are recommended for diagnostics and follow-up of NENs. The great advantage of 68Ga radiopharmaceuticals is that identical compounds can be labeled with therapeutic radionuclides 90Y and 177Lu.Conclusion. Peptide receptor radionuclide therapy is a systemic molecular target therapy that has proven to be safe and very effective in controlling the disease and prolonging the survival of patients with advanced and inoperable NETs. With a negligible number of adverse events, this therapy is safe and should be administered to all patients who meet the necessary criterias, primarily overexpression of the somatostatin receptor type 2.