Radiosurgery For Gliomas Research Articles

Radiosurgery for Gliomas

Stereotactic radiosurgery is a neurosurgical modality that involves delivering a large dose of focused radiation to a lesion while sparing the surrounding normal brain tissue. The biological properties of some gliomas, specifically relating to their oxygenation and invasiveness, can make them good targets for stereotactic radiosurgery. Although randomized controlled studies are lacking, preliminary data suggest that radiosurgery may be a viable alternative for low-grade gliomas, with improved survival and a low rate of complications. Although the prognosis for malignant gliomas is poor even after radiosurgery, it is possible the radiosurgical treatment can allow the surgeon more flexibility in terms of operative planning and subsequently result in better quality of life for patients post-operatively.

The role of the gamma knife in the treatment of malignant primary and metastatic brain tumors.

Gamma knife treatment is a clinically effective, safe, and cost-effective adjunctive therapy for primary malignant brain tumors. For most brain metastases, radiosurgery is the treatment of choice and will result in effective tumor control in more than 90% of treated tumors.

Gamma knife for glioma: Selection factors and survival

Purpose: To determine factors associated with survival differences in patients treated with radiosurgery for glioma.Methods and Materials: We analyzed 189 patients treated with Gamma Knife radiosurgery for primary or recurrent glioma World Health Organization (WHO) Grades 1–4.Results: The median minimum tumor dose was 16 Gy (8–30 Gy) and the median tumor volume was 5.9 cc (1.3–52 cc.) Brachytherapy selection criteria were satisfied in 65% of patients. Median follow-up of all surviving patients was 65 weeks after radiosurgery. For primary glioblastoma patients, median survival from the date of pathologic diagnosis was 86 weeks if brachytherapy criteria were satisfied and 40 weeks if they were not (p = 0.01), indicating that selection factors strongly influence survival. Multivariate analysis showed that increased survival was associated with five variables: lower pathologic grade, younger age, increased Karnofsky performance status (KPS), smaller tumor volume, and unifocal tumor. Survival was not found to be significantly related to radiosurgical technical parameters (dose, number of isocenters, prescription isodose percent, inhomogeneity) or extent of preradiosurgery surgery. We developed a hazard ratio model that is independent of the technical details of radiosurgery and applied it to reported radiosurgery and brachytherapy series, demonstrating a significant correlation between survival and hazard ratio.Conclusions: Survival after radiosurgery for glioma is strongly related to five selection variables. Much of the variation in survival reported in previous series can be attributed to differences in distributions of these variables. These variables should be considered in selecting patients for radiosurgery and in the design of future studies.