THE USE OF STEREOTAXIC RADIOSURGICAL BOOST IN THE TREATMENT OF MEDULLOBLASTOMAS

Purpose: Starting in 1992, we began using a stereotactic radiosurgical (SRS) boost for the treatment of medulloblastomas. Four patients rang ing in age from 7 to 42 years old have since been treated and are the subject of this retrospective study, Methods and Materials: All patien ts were initially treated with a maximally debulking surgery and exter nal beam radiotherapy, which were then followed by a stereotactic radi osurgical boost using a modified 6 MeV linear accelerator, Radiosurgic al boost doses ranged from 4.50 to 10.0 Gy, Target volumes ranged from 1.1 to 8.1 cc, The procedure was well tolerated with minimal acute to xicities, Results: All four patients are alive without evidence of rec urrence (at 8 to 35 months), Acute nausea and vomiting was elicited du ring the radiosurgical procedure in the first patient treated, We have since begun premedicating patients with antiemetics or treating under general anesthesia, Late complications consisted of panhypopituitaris m in one patient, which was thought to be attributable to the previous course of whole-brain radiotherapy, We have not observed any incidenc e of radionecrosis in this small cohort of patients, Conclusions: Our preliminary results with the use of radiosurgery for medulloblastomas are optimistic, and we would like to suggest the inclusion of a radios urgery boost in future clinical trials for treatment of this disease, (C) 1997 Elsevier Science Inc.