9.11Therapy

9.11.1 Neurosurgical Procedure

•Neurosurgery, including microscopic techniques, ultrasonic aspiration, and laser techniques, to achieve maximum tumor removal and low morbidity, depending on the location and extent of the tumor

•Often preoperative relief of intracranial pressure by ventriculoperitoneal or ventriculoarterial shunt

•Preoperative reduction of tumor edema by corticosteroids (dexamethasone 0.5–1 mg/kg body weight every 6 h), which also reduces the clinical symptomatology. In tumors of the hypothalamic region, hormonal replacement presurgery, during surgery, and postsurgery is common

–Presurgery tumor reduction by chemotherapy or radiotherapy: avoidance or reduction of morbidity and risk to the development of nervous system sequelae, especially in children younger than 2–3 years of age

–In low-grade tumors: expectant observation and diagnostic evaluation

•In patients with seizures, anticonvulsive therapy is necessary

•In patients with the potential for severe adverse sequelae from surgery, stereotactic biopsy can be carried out using CT-guided techniques

•Histological documentation is necessary, with the exception of diffuse, infiltrative chiasmatic or brain stem tumors

9.11.2 Radiotherapy

•Whether radiotherapy is indicated, and extension and volume of irradiation depend on the biology and histology of the tumor, the age of the child, and combination with chemotherapy or neurosurgery

•Irradiation during the first 3 years of life in special cases only, because of rapid growth of the brain and adverse long-term sequelae

•The planning and application of radiotherapy is time-consuming and demands experienced teamwork between radiation oncologists and pediatric oncologists

–In small children, daily sedation is indicated

–Hyperfractionated irradiation: subdivision of daily radiation volume in two applications, with an interval of 6–8 h

•Complications of irradiation:

–Depends on volume, fractionation, and radioactive source

–Acute reaction: brain edema

–Subacute reaction: postradiation syndrome with fever, lethargy; often 4–6 weeks after radiotherapy. Duration: usually 1–2 weeks, but can last for several weeks

–Long-term sequelae: deficiency of cognitive and neuropsychological development, memory deficits, deterioration of intelligence quotient after whole brain irradiation, rarely myelopathy after spinal axis irradiation, especially when dose exceeds 40 Gy