Pediatric Brain Tumors

Abstract

• Brain tumors are the second most common group of malignancies in children.

• For some pediatric tumors such as medulloblastoma, supratentorial primitive neuroectodermal tumor (PNET), ependymoma and germ cell tumors, leptomeningeal dissemination is a route of spread. Imaging of the entire neuraxis is performed in addition to cerebral spinal fluid (CSF) cytology from a lumbar tap.

• For low-grade gliomas, surgery is the mainstay of treatment. Adjuvant therapy is not needed for patients who have gross total resections.

• Diffuse pontine gliomas are the most common brainstem gliomas in children. Radiation to a dose of 54 Gy in 30 fractions over 6 weeks is the standard treatment.

• Current treatment strategies in medulloblastoma, which include maximal safe resection, craniospinal irradiation (CSI) followed by primary site irradiation, and chemotherapy, have resulted in 5-year progression-free survivals of 80 and 70% for standard- and high-risk patients.

• The extent of resection is the most important prognostic factor for ependymoma.

• Adjuvant radiotherapy is currently recommended for ependymoma, regardless of extent of resection.

• Germ cell tumors are divided into germinoma and nongerminomatous germ cell tumor (NGGCT), with the former having a better prognosis. Germinomas are highly curable with radiotherapy alone, while NGGCT is best managed with a combination of radiation and chemotherapy.

• Late effects of radiotherapy in young children (<3 years of age) with medulloblastoma, ependymoma, and malignant glioma have prompted investigators to delay or possibly eliminate radiotherapy by using chemotherapy.

• The current trend for treatment of craniopharyngiomas is limited surgery or biopsy followed by radiotherapy, as achieving a gross total resection may result in significant morbidity because of the proximity of critical structures such as the optic chiasm and nerves, circle of Willis, and hypothalamus to the tumor.