Target Volume Delineation for Radiation Therapy of High-Grade Gliomas
High-grade gliomas are characterized by rapid growth, poor prognosis and frequent unsatisfactory treatment results. Radiation therapy remains one of the main methods of treatment of this disease. However, the question of choosing the optimal macroscopic (Gross Tumor Volume - GTV) and clinical (Clinical Target Volume - CTV) volumes in the planning of radiation treatment remains controversial. There are several approaches to the target volume delineation for radiotherapy of high-grade gliomas, depending on the peritumoral edema. There is no correlation between the frequency of recurrences and methods of delineation of gliomas. GTV should be defined as the area of enhancement on the post-contrast T1-weighted MRI, i.e. postoperative cavity and residual tumor. Peritumoral edema is an unreliable orienting point when contouring target volumes.