Radiation therapy in the management of pediatric craniopharyngiomas--a review

Abstract

Craniopharyngiomas are benign suprasellar tumors that arise from epithelial remnants of the Rathke's pouch. The two standard treatment options are primary total resection or limited surgery followed by external beam radiation. The 10- and 20-year progression-free survival rates following limited surgery and radiation therapy are superior to those achieved by primary surgery alone. The side effect profiles for these two treatment approaches are different. Following total resection there is a very high incidence of panhypopituitarism requiring lifelong multiple hormone replacement therapy. The other side effects include potential damage to adjacent structures such as optic chiasm, vasculature and hypothalamus. Following limited surgery and radiation therapy the incidence of endocrine deficits is significantly lower compared to radical surgery, as is the risk of neurovascular and hypothalamic injury. Optic neuropathy and brain necrosis are rare in modern radiation therapy series. Second malignant neoplasms, although rare, can occur. In children with recurrent craniopharyngiomas following radical surgery, the recommended salvage treatment is radiation therapy, as further surgical attempts at salvage are associated with high relapse rates and increased morbidity and mortality. There have been significant technological advances in the field of radiation treatment planning and delivery that have great potential for reducing the incidence of long-term irradiation sequelae in the developing brain. The general availability of megavoltage linear accelerators and modern radiotherapy innovations such as three-dimensional conformal radiation treatment (3D CRT), stereotactic radiosurgery (SRS), stereotactic radiotherapy (SRT), and intensity modulated radiation therapy (IMRT) should further limit the rate of complications and improve cure rates in children with primary or recurrent craniopharyngioma.