Radiosurgery or hypofractionated stereotactic radiotherapy after craniospinal irradiation in children and adults with medulloblastoma and ependymoma

PURPOSE: To assess the results and tolerance of radiosurgery/hypofractionated stereotactic radiotherapy performed after craniospinal irradiation for recurrent tumor. METHODS: Fourteen patients aged 3–46 years, diagnosed with medulloblastoma (10), anaplastic ependymoma (3), and primitive neuroectodermal tumor (1). All patients had craniospinal irradiation (CSI) with the total dose of 30.6–36 Gy and boost to 53.9–60 Gy either during primary or during second-line treatment. Twelve patients were irradiated with a single dose of 6–15 Gy (median 14.5 Gy). One received three fractions of 5 Gy and one six fractions of 5 Gy. In statistical analysis, the Kaplan-Meier method and log-rank test were used. The overall survival was calculated from the date of the end of stereotactic radiosurgery to the date of death or last contact. RESULTS: Recurrences were diagnosed after the median time of 16 months after the end of primary treatment. Eleven patients died during the follow-up. The follow-up for the 3 patients still alive was 6.7, 40.5, and 41.4 months, respectively. One- and 2-year overall survival (OS) was 70% and 39%. Patients who had ECOG performance status of 0 at the time of diagnosis of the disease trended to have better 2-year OS compared to those evaluated as ECOG 1 (p = 0.057). Treatment results were evaluable in 12 patients. Local control (stabilization or regression of the lesion) was achieved in 9 (75%). Overall disease progression was 67%. No patient developed radiation-induced necrosis. The treatment was well tolerated and no serious adverse effects were observed. Eleven patients were given steroids as a prevention of brain edema and four of them needed continuation of this treatment afterwards. In 7 patients, symptoms of brain edema were observed during the first weeks after reirradiation. CONCLUSIONS: Stereotactic radiosurgery or hypofractionated stereotactic radiotherapy is an effective treatment method of the local recurrence after CSI and can be performed safely in heavily pre-treated patients.