Radiation therapy

For patients with diffuse midline glioma, H3 K27-altered and diffuse pediatric-type high-grade glioma, H3-wild type and IDH-wild type, focal radiation therapy is routinely administered to a field that widely encompasses the entire tumor. The radiation therapy dose to the tumor bed is usually at least 54 Gy. Despite such therapy, the prognosis is dismal. Similarly poor survival is seen in children with spinal cord primary tumors and children with thalamic high-grade gliomas (i.e., diffuse midline gliomas, H3 K27M-altered tumors) treated with radiation therapy.[18,19]; [20,21][Level of evidence C1]

Standard treatment for children with diffuse midline gliomas centered in the pons is radiation therapy to the involved site. The conventional dose of radiation ranges between 54 Gy and 60 Gy, given locally to the primary tumor site in single daily fractions. Such treatment will result in transient benefit for most patients, but more than 90% of patients will die within 18 months of diagnosis.[22]

Radiation-induced changes may occur a few months after the completion of radiation therapy and may mimic tumor progression. When considering the efficacy of additional treatment, care needs to be taken to separate radiation-induced change from progressive disease.[23]

Research studies that evaluated the efficacy of hyperfractionated and hypofractionated radiation therapy and radiosensitizers have not demonstrated improved outcomes using these radiation techniques.