P09.05 Treatment strategy of MRI postcontrast non-enhanced gliomas

Abstract BACKGROUND MRI postcontrast nonenhanced brain tumors are found benign biologic entities with the better prognosis. The aim of this paper is to evaluate predictive features on MRI considered definite diagnosis occurrence, tumor progression, upgrading and postcontrast enhancement evolution on follow-up serial MRI. MATERIAL AND METHODS We retrospectively collected patients with the initially MRI postcontrast nonenhanced brain tumors, treated in our hospital from January 2009 to June 1, 2006. All tumors were converted into WHO 2016 IDH status classifications in accordance with current recommendations. Information about surgeries, patient clinical condition, MRI, and results of histological, immunohistochemical, molecular genetic, and cytogenetic investigations were gathered. Semiautomatic segmentations were performed using FSLeyes software (part of FSL package) on preoperative and followed-up 3D T1-w MPRAGE, T2-w or FLAIR scans. We focused on residual tumor volume, and time distribution of T2/FLAIR changes and T1-w postcontrast enhancement evolution. RESULTS Seventy-eight patients were enrolled in this study. There were 47 gliomas grade II 22 grade III and 9 grade IV. Glioma II comprised 35 diffuse astrocytomas (23 patients had IDH1 mutation). Nine gliomas grade III and 6 gliomas grade IV had IDH1 mutation. Overall survival in glioma group grade II, grade III, grade IV was 187.9 months, 71.1 months and 25.2 months, respectively. Oncotherapy underwent 14 gliomas grade II after first surgery, 13 patients had radiotherapy a 1 patient had neoadjuvant chemotherapy. Seventeen gliomas grade III were indicated to oncotherapy, 5 patients had radiotherapy and 12 had chemoradiotherapy. All patients with glioma grade IV experienced oncotherapy. Time to progression of non-contrast enhanced brain tumor was 5.8 years. Time to up-grading of non-contrast enhanced brain tumor was 16.8 months. Detailed time relations of glioma subgroup will be displayed in tables. CONCLUSION Regarding MRI postcontrast non-enhanced tumors, predominantly low grade gliomas (LGG), aggressive oncotherapy are reluctant to use but they are prone to repeat surgeries. Decision making issues are age, clinical patient status, histologic and genetic tumor characteristics, residual tumor volume, published guidelines for brain tumor treatment, and patient′s willing. Generally, hyposignal on the T1 postcontrast scans strictly relate to the better prognosis, even in HGG. Longer survival expectancy incr