IDH1 and oligodendroglioma: Based on the 2016 WHO classification, 45 (29.4%) patients had oligodendroglioma, IDH-mutant and 1p/19q codeleted (ODG); 80 (52.3%) had diffuse astrocytoma, IDH-mutant (IDHmt); and 28 (18.3%) had diffuse astrocytoma, IDH-wildtype (IDHwt).