P02.17.A FEATURES OF METABOLIC PSEUDO-PROGRESSION VISUALIZATION OF GRADE 3-4 GLIOMAS AFTER COMBINATION THERAPY. CORRELATION WITH MRI

Abstract

Abstract BACKGROUND Follow-ap assessment of post-therapeutic changes in gliomas of 3-4 raids revealed the phenomen of metabolic pseudoprogression. This feature was manifested in a transistor increase in the capture of the radiopharmaceutical. This "anomaly" requires study for a correct differential diagnosis between progression and pseudoprogression MATERIAL AND METHODS For the period from 2019 to 2023, 27 patients aged 24-72 years (average age 55 years) with the phenomena of metabolic pseudoprogression of 3-4 grades gliomas after combination therapy participated in the study. The studies were carried out using PET-CT and 1.5T, 3.0T MR scanners using T2, T2 flair, T13D before and after contrast, T2* perfusion. Postprocessing was carried out using a workstation SINGO.VIA using technological processes: neuro3d, MM oncology, MR neurology. RESULTS It was found that in all cases of transient increase in radiopharmaceuticals capture after radiotherapy in terms from 9 months to 36 months, the values of radiopharmaceuticals accumulation were determined in the range of 1.8-3.5 and were they were divided into two groups according to MRI data: group A (n=17) with structural changes, group B (n=10) with a stable MR pattern. According to MRI data in group A, there was an increase in the pathological zone, these changes involved white matter with more pronounced changes in the periventricular regions. In group B, the changes concerned gray matter. In addition, changes in group B were accompanied by manifestations of vasculopathy of the SMART type (Stroke-Like Migraine Attacks After Radiation Therapy). In subsequent observations, these changes in both groups were reduced, both according to PET and MRI CONCLUSION A temporary increase in the values of the capture of radiopharmaceuticals after combination therapy for high grade gliomas can be determined both in the white and gray matter of the brain. This may correspond to the manifestations of a post-radiation reaction. Compared with the MRI data, there is a difference in morphological manifestations at the level of gray and white matter, which is probably due to their different radioresistance. These newly discovered factors may be of key importance for further treatment of patients