18F-fluoroethyltyrozine positron emission tomography combined with computed tomography and computed tomography perfusion in complex diagnostic of glial brain tumors

The study objective is to evaluate the diagnostic capabilities of complex method based on the use of 18 F-fluoroethyltyrozine positron emission tomography (PET) combined with computed tomography (CT) and CT perfusion in the differential diagnosis of glial brain tumors.Materials and methods. One hundred and two patients with glial brain tumors were included in the study. Depending on the degree of malignancy patients were divided into 2 groups: group 1–38 (37.26 %) patients with grade I–II tumors; group 2–64 (62.74 %) patients with grade III–IV tumors. Perfusion CT was performed in 20 (52.6 %) patients from the group with grade I–II tumors and 37 (57.8 %) patients from the group with grade III–IV gliomas. The sensitivity and specificity of such indicators as the maximum standardized uptake value (maxSUV) and the tumor to brain ratio (TBR), in combination with CT perfusion indicators (cerebral blood flow (CBF), cerebral blood volume (CBV), vascular permeability (FED) were studied.Results. The highest diagnostic accuracy was demonstrated by the following parameters: maxSUV 1 (sensitivity and specificity 81 and 82 %, threshold value 2.51, AUC 0.87); TBR 1 (sensitivity and specificity 90.6 and 81.6 %, threshold value 2.07, AUC 0.89). The comprehensive evaluation of CT perfusion and 18 F-fluoroethyltyrozine PET / CT parameters: sensitivity and specificity of TBR 1 + CBF – 97.1 and 94.4 %, respectively; TBR 1 + CBV – 96.6 and 94.4 %, respectively; TBR 1 + FED – 94.6 and 92.3 %, respectively.Conclusion. According to results of obtained analysis, an increase in diagnostic accuracy was revealed for all studied parameters with complex use of two methods – 18 F-fluoroethyltyrozine PET / CT and CT perfusion, in differential diagnosis of glial brain tumors.