Adjuvant Gamma Knife radiosurgery following surgical resection of brain metastases: a 9-year retrospective cohort study.

Given the potential morbidity of whole brain radiation therapy (WBRT), there has been an increasing trend to defer WBRT and deliver Gamma Knife stereotactic radiosurgery (GKS) to cerebral metastatic lesions. We analyzed our experience delivering GKS to the tumor cavity following surgical resection of brain metastases and compared our results to patients receiving WBRT after surgical resection of a metastatic lesion. We performed a retrospective review of patients undergoing surgical resection of at least one brain metastasis between December 1999 and December 2008. Both univariate and multivariate Cox proportional hazards regression were utilized to analyze the influence of various prognostic factors on survival. Twenty-five patients had a metastatic lesion resected followed by adjuvant GKS to the resection cavity while another 18 had surgical resection followed by WBRT. Aside from a disparity in gender distribution (72% of GKS patients were female while women only constituted 28% of the WBRT group), no significant differences existed between groups. The median survival for patients receiving GKS was 15.00 months as compared to 6.81 months among those receiving WBRT (P = 0.08). Univariate Cox regression analysis identified the number of metastases (HR 1.65, 95% CI 1.07-2.54, P = 0.02) and regional recurrence (RR 5.23, 95% CI 1.78-15.38, P = 0.003) as poor prognostic factors. Multivariate regression analysis showed that regional recurrence (HR 5.17, 95% CI 1.69-15.78, P = 0.004) was again strongly associated with worse survival. Although limited by the retrospective nature of our study and lack of some clinical measures, patients undergoing GKS to the resection cavity had a trend towards longer median survival.

Postoperative temporalis muscle atrophy and the use of electrocautery: a volumetric MRI comparison.

Postoperative temporalis muscle atrophy from injury to the neurovascular supply can cause significant cosmetic disfigurement, and avoidance of electrocautery use has become a common practice in minimizing this outcome. We attempted to quantify the effects of electrocautery on temporalis atrophy by retrospectively reviewing postoperative magnetic resonance images in patients having undergone an orbital frontal craniotomy. We reviewed medical records and compared volumetric measurements of the temporalis muscle in 25 patients using the contralateral temporalis muscle as an internal control. The mean size of the nonsurgical temporalis muscle was 24.6 cm(3) as compared with 23.6 cm(3) on the operated side. The difference of 1.0 cm(3) was not statistically significant (p = 0.32). The only postoperative atrophy noted visually on the magnetic resonance images developed in the posterior superior aspect of the temporalis muscle, behind the vertical incision of the temporalis muscle. In the small control group, with known injury to V3, the mean nonsurgical size was 27.7 cm(3), whereas it was 16.5 cm(3) on the contralateral surgical side. The difference of 11.2 cm(3) was statistically significant (p = 0.04). These findings suggest that the use of electrocautery to dissect the temporalis muscle does not significantly contribute to atrophy provided careful surgical technique is practiced.