Case-control study of stereotactic radiosurgery for recurrent glioblastoma multiforme

Object. The role of stereotactic radiosurgery (SRS) for recurrent glioblastoma multiforme (GBM) was evaluated in a case-control study. Methods. All patients who underwent SRS for recurrent GBM before March 2003 formed the case group. A control group of patients who did not undergo SRS was created from an institutional database, and each case was matched for known prognostic factors in GBM. The medical and neuroimaging records of all the patients were reviewed, and survival and treatment outcomes were recorded. The case and control groups were well matched with regard to demographics and pre-SRS interventions. In the control group, the date on which magnetic resonance imaging identified a recurrent lesion that would have been eligible for SRS was deemed the "SRS" date. The number of surgeries performed in the control group was statistically higher than that in the case group. The median duration of overall survival from diagnosis was 26 months in the case group and 23 months in the control group. From the date of SRS or "SRS", the median duration of survival was 11 months in the case group and 10 months in the control group, a difference that was not statistically significant. Conclusions. It appears that a subgroup of patients with GBMs has a higher than expected median survival duration despite the initial prognostic factors. In patients with localized recurrences, survival may be prolonged by applying aggressive local disease management by using either SRS or resection to equal advantage.