[Comparative assessment of the diagnostic capacities of PET with 18FDG and 1-[11C] sodium butyrate in the examination of patients with tumors of the brain and cerebral circulatory disorders: results of semiquantitative assessment].

The purpose of the present study was to determine the capacities of differential diagnosis of the bulky masses of the brain by positron emission tomography (PET) with 11C-butyrate by the direct indication--the tumor RFP level measured by means of the semiquantitative indicator--the differential accumulation coefficient (DAC). For comparison, 18FDG PET widely used to detect malignant tumors was preliminarily made. Brain PET was performed in 86 patients (45 males and 41 females whose age ranged from 18 to 69 years to identify bulky masses or to rule out continuous tumor growth. In all cases, the data were histologically and morphologically verified. Of the 86 patients, 21 were found to have malignant tumors, 41 had benign tumors, arteriovenous malformations, cerebral circulatory disorders, and cysts were detected in 3, 7, and 14 cases, respectively. The level of 18FDG accumulation was ascertained to be directly related to the grade of malignancy. In 20 of the 21 patients with malignant tumors, DAC for 18FDG was greater than 1. However, it was impossible to differentiate benign tumors and non-tumoral masses by using only 18FDG. Comparing the data obtained by means of 18FDG and 11C-butyrate revealed their comparability in detecting neoplasms. Patients with vascular tumors (benign meningioma and adenoma of the pituitary were an exception. Their DAC for 11C-butyrate was greater than 1. In follow-up CT scanning, just a single injection of 11C-butyrate may allow one to estimate the vascular and tissue components of masses, which facilitates the identification of vascular non-tumoral processes and tumors. The additional criterion that allows a neoplasm to be differentiated from nontumoral processes permits a rapid tumor release of a radioactive label.