Imaging brain tumors – 1 – Introduction and classification
Brain tumors are one of the most common diagnoses addressed in neuroradiology. This covers a wide spectrum of disease, from primary brain tumors like gliomas and glioblastomas to secondary disease like metastases. This lecture covers the spectrum of the most common brain tumors, with an emphasis on primary brain tumor.
This first video discusses how brain tumors are classified, the genetics of these tumors, and a general approach to brain tumors. Tumors can be divided into a few categories, including astrocytomas, oligodendrogliomas, other low grade glial tumors, and common non-glial tumors. Since the WHO reclassification occurred in 2016, genetic information has been used to classify tumors, with the most important mutations being isocitrate dehydrogenase (IDH), 1p19q codeletion, and MGMT methylation. Oligodendrogliomas must be IDH mutants and 1p19q codeleted, and other tumors are now classified as astrocytomas.
IDH mutation is associated with lower grade astrocytomas and is associated with a survival advantage. Similar, MGMT methylation is associated with a better response to radiation, more pseudoprogression, and better survival.
Additional videos in the playlist will address the imaging findings of brain tumors, such as astrocytomas,oligodendrogliomas, other low grade glial tumors,and non-glial tumors. Other videos address how to form a differential diagnosis for a brain tumor, and some challenge cases to apply your skills.
The level of this lecture is appropriate for radiology residents, radiology fellows, and trainees in other specialties who have an interest in neuroradiology or may see patients with brain tumors.