Modern methods for radionuclide diagnosis of tumors and non-tumor pathologies of the brain

The review analyzes the global experience in the application of nuclear medicine techniques for diagnosis of tumors and non-tumor pathologies of the brain. The main groups of radiopharmaceuticals currently used for imaging of malignant brain tumors and diagnosis of cognitive impairments and neurotransmitter system disturbances by means of single-photon emission computed tomography and positron emission tomography are described.Modern approaches to the application of methods for radionuclide diagnosis in neuro-oncology and neurology are compared, and the main trends in production of new, more specific radiopharmaceuticals for visualizing brain tumors of various degrees of malignancy and diagnosing non-tumor pathologies of the brain are described. The review discusses the advantages and disadvantages of currently used techniques and radiopharmaceuticals for imaging of central nervous system disorders, depending on the clinical situation and specific diagnostic tasks.In addition, the review presents consolidated recommendations of the leading scientific schools in neuro-oncology on the use of nuclear medicine techniques in patients with brain tumors at the stages of treatment and follow-up. The presented article examines the experience of domestic scientific schools in the development of radiopharmaceuticals for neuro-oncology. The features of the development and use of new radiopharmaceuticals in patients with brain tumors and neurodegenerative diseases are highlighted. The review is based on the analysis of literature included in the Scopus, Web of Science, MedLine, The Cochrane Library, EMBASE, Global Health, and RSCI databases.

Alternative scaffolds in radionuclide diagnosis of malignancies

This review discusses a relatively new class of targeted molecules that is being actively studied for radionuclide diagnosis and treatment of malignancies. The full-size antibodies used so far have non-optimal pharmacological properties, slow distribution in the body, poor penetration into the tissue and kidney excretion, and high immunogenicity, which significantly complicates their use in clinical practice. Over the past decade, a new class of targeted molecules, called “non-immunoglobulin scaffolds” have become popular; they have all the requirements for optimal delivery of a radionuclide to tumor cells. Scaffolds usually are smaller in size in comparison with antibodies, but they are larger than peptides, and are characterized by high affinity and optimal biochemical, biophysical, biological, and economic features. The advantages of such proteins are their stable structure, good penetration into tissues, the possibility of additional functionalization and expression in the bacterial system, which ensures low production costs.The results of preclinical and clinical studies for diagnosis of malignancies using such proteins as affibody, adnectin, DARPins, etc., have demonstrated their high specificity, affinity, good tolerance and low immunogenicity.