10153- NQPC-7 ADVANCING COGNITIVE ASSESSMENT IN GLIOBLASTOMA TREATMENT WITH MOLECULAR IMAGING (THK5351 PET)

Abstract INTRODUCTION Cancer treatment-related higher brain dysfunction significantly impacts quality of life (QOL) and social life. This study investigates the relationship between PET accumulation areas and advancing cognitive assessment in glioblastoma IDH-wild type (GBM) patients using the PET tracer THK5351, developed to detect tau protein. METHODS Twenty-four GBM patients who underwent changes in tumor to normal ratio (TNR) and metabolic tumor volume (MTV) for THK5351 evaluation before and after temozolomide (TMZ), bevacizumab (Bev), and radiation therapy from February 2020 to March 2024 were included. Cognitive assessments included the Mini-Mental State Examination (MMSE), Trail Making Test (TMT), Frontal Assessment Battery (FAB), Raven’s Coloured Progressive Matrices (RCPM), and Kohs block-design test (Kohs), administered at admission and discharge. RESULTS The mean age of the patients was 70.5 years (14 males, 10 females). All patients were diagnosed with GBM and received TMZ, Bev, and radiation therapy. In 11 patients, a reduction in THK5351 MTV correlated with MMSE improvement. However, 5 patients showed TMT deterioration, with a significant increase in THK5351 TNR change. FAB scores increased in 3 patients, while RCPM and Kohs scores deteriorated in 1 patient, alongside an increase in THK5351 TNR change. Among the 13 patients with enlarged THK5351 MTV, 5 showed decreased MMSE scores, and 3 showed decreased TMT and FAB scores. These cases exhibited an increased THK5351 TNR change, with accumulation expanding from the medial thalamus to the anterior nuclei of the thalamus, hypothalamus, caudate nucleus, hippocampus, and corpus callosum. Patients with reduced THK5351 TNR but enlarged THK5351 MTV had improved MMSE scores but decreased motivation and cognitive function. CONCLUSION Improving the GBM removal rate and preserving function requires attention to THK5351 accumulation in the corpus callosum, hippocampus, and hypothalamus for advancing cognitive assessment.