A Modern View of the Use of Positron Emission Tomography with ¹⁸F-fluoroethyltyrosine Combined with Computed Tomography in Neurooncology

Positron emission tomography combined with computed tomography (PET/CT) allows for assessment of not only anatomical and structural, but also metabolic changes in tumor masses. 18 F-fluoroethyl tyrosine ( 18 F-FET) PET/CT is based on evaluation of transport of 18 F-labeled amino acid tyrosine in tissues. Precise evaluation of brain tumor WHO Grade (I-IV) is a crucial step in assessment of prognosis and treatment planning for patients with glial neoplasms. 18 F-FET PET-tracer allows to carry out multi-stage and dynamic examinations, which significantly increases method’s sensitivity. 18 F-FET PET makes it possible to acquire information about tumor tissue metabolism and to determine the most proliferatively active parts of neoplasm. In addition to glial neoplasms, a topical matter of neuro-oncology is the metastatic lesions of the central nervous system. It is highly important for the prognosis and therapeutic tactics to differentiate between brain tumors recurrence, post-treatment changes and mixed lesions. The use of 18 F-FET PET-tracer provides high specificity of the obtained diagnostic data which allows for precise determination of an optimal biopsy site and radiation-treatment planning, as well as for differential diagnosis in cases of suspected tumor recurrence. 18 F-FET PET/CT demonstrated high efficiency in differentiation of actively proliferating neoplasms from conditionally benign tumors, as well as from manifestations of iatrogenic nature, primarily after radiation-treatment.