The complementary role of MRI and FET PET in high grade gliomas to differentiate recurrence from radionecrosis

Background Conventional magnetic resonance imaging (MRI) has limitations in differentiating tumor recurrence (TR) from radionecrosis (RN) high grade gliomas (HGG), which can present with morphologically similar appearances. Multiparametric advanced MR sequences and Positron Emission Tomography (PET) amino acid tracers aid diagnosing metabolism. The role of both modalities on an individual basis combined performances were investigated the current study. Materials Methods Patients HGG MRI PET within three weeks included retrospective analysis. multiparametric T1-contrast, T2-weighted sequences, perfusion, diffusion, spectroscopy. was interpreted by neuroradiologist without using information imaging. 18F-Fluoroethyl-Tyrosine (FET) uptake calculated areas maximum enhancement/suspicion, assessed nuclear medicine physician (having access to determine tumor-to-white matter ratio over a specific region). A definitive diagnosis TR or RN made based combination multidisciplinary joint clinic decisions, histopathological examination, clinic-radiological follow-up as applicable. Results 62 patients study between July 2018 August 2021. histology during initial glioblastoma, oligodendroglioma, astrocytoma 43, 7, 6, respectively, while no histological characterization available. median time radiation (RT) 23 months. 46 16 had recurrence, respectively. Sensitivity, specificity, accuracy 98, 77, 94%, Using T/W cut-off 2.65, sensitivity, 79, 84, 80%, best results obtained 100, 98%, Conclusion Combined FET-PET offers assessment glioma that is correlative complimentary, higher clinical value.