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BACKGROUND Melanoma is the primary malignancy that is most likely to metastasize to the brain. Because such an event carries an almost uniformly poor prognosis, the current study reviewed outcomes and identified associated prognostic indicators for 51 consecutive patients receiving gamma knife (GK) radiosurgery in the initial treatment of 188 intracranial melanoma metastases. METHODS Data were collected retrospectively from a single‐center GK radiosurgery database and from primary patient medical records and radiographs. RESULTS At presentation, 71% of patients had multiple intracranial metastases, and extracranial metastases were present in 66% of patients. Thirty‐two patients (63%) were initially treated with GK radiosurgery alone, whereas the remainder received GK radiosurgery in combination with surgery and/or whole‐brain radiotherapy (WBRT). Overall median survival from time of GK radiosurgery was 26 weeks. Subgroup analysis revealed a median survival of 77 weeks for patients presenting with a single lesion, compared with 20 weeks for patients presenting with multiple lesions (P = 0.003). Patients in recursive partitioning analysis (RPA) Class I survived a median of 57 weeks, compared with a median survival of 20 weeks for patients in RPA Class II or III (P = 0.002). Although long‐term imaging follow‐up revealed that a majority of patients experienced distant brain metastases, multivariate analysis showed that distant metastases occurred significantly sooner in patients with extracranial metastases (P = 0.0004). Addition of initial WBRT had no significant effect on the time to development of new brain metastases (P = 0.13). Local control (crude) was observed in 81% of lesions initially treated with GK. Patients experienced improved or stable symptoms for a median of 37 weeks post–GK radiosurgery. CONCLUSIONS Survival analyses supported the use of GK radiosurgery in the initial treatment of patients with melanoma brain metastases, with best results occurring in patients presenting with a single lesion. Cancer 2004. © 2004 American Cancer Society.

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Background Dexmedetomidine is commonly used after congenital heart surgery and may be associated with a decreased incidence of post-operative tachyarrhythmias. Using a large cohort of patients undergoing congenital heart surgery, we examined for an association between dexmedetomidine use in the immediate post-operative period and subsequent arrhythmia development. Methods and Results A total of 1,593 surgical procedures for congenital heart disease were performed. Dexmedetomidine was administered in the immediate post-operative period after 468 (29%) surgical procedures. Compared to 1,125 controls, the group receiving dexmedetomidine demonstrated significantly fewer tachyarrhythmias (29% vs. 38%, p<0.001), tachyarrhythmias receiving intervention (14% vs. 23%, p<0.001), bradyarrhythmias (18% vs. 22%, p=0.03) and bradyarrhythmias receiving intervention (12% vs. 16%, p=0.04). After propensity score matching with 468 controls, the arrhythmia incidence between groups became similar: tachyarrhythmias (29% vs. 31%, p=0.66), tachyarrhythmias receiving intervention (14% vs. 17%, p=0.16), bradyarrhythmias (18% vs. 15%, p=0.44) and bradyarrhythmias receiving intervention (12% vs. 9%, p=0.17). After excluding controls exposed to dexmedetomidine at a later time in the hospitalization, dexmedetomidine was associated with increased odds of bradyarrhythmias receiving intervention (odds ratio [OR] 2.18, 95% confidence interval (CI) 1.02 – 4.65). Furthermore, there was a dose-dependent increase in the odds of bradyarrhythmias (OR 1.04, 95% CI 1.01 – 1.07) and bradyarrhythmias receiving intervention (OR 1.05, 95% CI 1.01 – 1.08). Conclusions While dexmedetomidine exposure in the immediate post-operative period is not associated with a clinically meaningful difference in the incidence of tachyarrhythmias after congenital heart surgery, it may be associated with increased odds of bradyarrhythmias.