Radiotherapeutic approaches in the treatment of adult gliomas

In the Summer of 2021 the World Health Organization (WHO) issued a reclassification of central nervous system (CNS) malignancies, which would ultimately change how adult gliomas would be defined, classified, and treated. The 2021 update emphasized molecular diagnostics in its reclassification of tumors, while also staying true to prior incorporation of both histology and immunohistochemistry. This chapter will summarize these definitions, epidemiology, work-up, and management of adult diffuse gliomas with an emphasis on radiotherapy (RT) treatment planning.