Results of three-dimensional stereotactically-guided radiotherapy in recurrent medulloblastoma

Purpose: To evaluate survival rates and side effects after stereotactically-guided radiotherapy (SRT) in patients with recurrent medulloblastoma of the brain. Methods and materials: Between 1992 and 2000, 20 patients with 29 radiological manifestations were treated with fractionated SRT (n = 21) or radiosurgery (n = 8). Median age was 16 years with 6 patients less than or equal to14 years. All patients had prior cranio-spinal radiotherapy plus boost to the posterior fossa with a total dose of 54 Gy. Time to recurrence was 33 months mean. Eighteen of the 29 lesions were located within the boost volume. Chemotherapy was given according to current international study protocols (HIT) in all patients. Mean total dose for re-irradiation was 24 Gy for fractionated stereotactically-guided radiotherapy, and 15 Gy for radiosurgery. Mean follow-up was 88.5 months. Results: Overall local control was 89.7%. Thirteen recurrences showed partial or complete response in CT/MR-imaging, 13 showed stable disease. Local tumor progression was seen 5 months mean after radiotherapy in three cases. A multifocal intracranial progression was seen in 9 patients, 5 patients developed additional spinal metastases. Thirteen patients died with disseminated cranio-spinal progression, after 72.6 months median. No late toxicity > CTC IIdegrees especially no brain radionecrosis was seen after radiotherapy. Conclusion: SRT is effective and safe in the treatment of recurrent medulloblastoma to improve local control without evident side effects. The main problem remains the control of subclinical cranio-spinal dissemination.