Radiosurgery in the management of pediatric brain tumors.

Abstract

A total of 114 patients with benign and malignant intracranial tumors were treated by Valentino at the Flaminia Radiosurgical Center using a Philips 6-MeV linear accelerator between 1987 and 1995. The tumor locations break down as follows: 36 in the cerebral hemispheres, 14 in the region of the hypothalamus/optic chiasm, 21 in the III ventricle/pineal region, 3 in the basal ganglia, 27 in the posterior fossa, 13 in the brain stem. Seventy-nine patients had multivariate/combined treatment consisting of surgery or biopsy followed by chemotherapy, radiotherapy and/or radiosurgery. Thirty-five were not operated on or biopsied but were treated primarily by radiosurgery, which was associated with chemotherapy and conventional radiotherapy. The short- and long-term results were evaluated separately for each pathology in an attempt to derive guidelines for future treatment. For tumors of the pineal region, we are of the opinion that radiosurgery is the treatment of choice in children and that more than one-third of patients can be cured by this means. The remaining patients require surgery and/or chemotherapy in addition. For medulloblastomas radiosurgery may be useful to control local recurrence if coupled with chemotherapy. In the case of ependymomas, partly because of the extreme malignancy of the lesions in our series, radiosurgery did not succeed in controlling local recurrence. We fear that limiting treatment to radiosurgery, rather than prescribing conventional radiotherapy when indicated, could permit CNS seeding. For craniopharyngiomas radiosurgery proved useful for controlling solid remnants. In glial tumors radiosurgery helped either to "sterilize" the tumor bed after removal or to treat remnants of the lesions in critical areas; for diffuse brain stem gliomas it should be considered the treatment of choice.