Effects of gamma knife radiosurgery for pediatric craniopharyngiomas

Seven cases of pediatric craniopharyngiomas have been treated by gamma knife and followed-up for a mean 24.1 months between May, 1991 and March, 1995. They included 4 boys and 3 girls with a mean age of 8.9 years. Initial signs and symptoms were: headaches in 2 cases, decrease in visual acuity in 6 cases, visual field deficit in 5 cases, hypopituitary function in 5 cases, and diabetes insipidus in one case. Prior to the radiosurgery, surgical therapy had been performed in 7 cases, conventional radiotherapy in one case, and chemotherapy in one case. Tumor were located in the chiasmal region in 3 cases and the suprasellar region in 4 cases. Mean tumor diameter was 18.5 mm. Mean and marginal irradiation dosages were 25.9 Gy and 13.4 Gy. Repeated MRI indicated marked shrinkage of tumors was obtained in all 7 cases. Follow up showed neurological signs and symptoms improved in 3 cases and remained unchanged in 4 cases, without any side-effects. Hormonal study indicated TSH decreased about one year after gamma knife radiosurgery. It is considered that gamma knife radiosurgery will be a safe and effective treatment for pediatric craniopharyngiomas in combination with microsurgery. (author)