Infratentorial glioblastoma: the role of neuraxis irradiation.

The patterns of clinical-and autopsy-documented tumor spread were evaluated for 15 patients with biopsy-proven infratentorial (8 cerebellar, 2 brainstem, 5 intramedullary spinal cord) glioblastoma. No patient developed clinical nor autopsy evidence of subarachnoid dissemination, even though no patient had received craniospinal axis irradiation. Fully 14 of the 21 previously reported patients with subarachnoid dissemination from infratentorial glioblastoma had this diagnosis made only at autopsy. The overall poor prognosis at present (8% 3-year survival from the present series and recent literature) along with the demonstrated pattern of local-regional aggressiveness as the major form of initial spread and post-irradiation recurrence, suggests that routine craniospinal axis irradiation may not be indicated for most patients with infratentorial glioblastoma.