Curability of skull base tumors is related to the ability to achieve a complete resection. Resection of the internal carotid artery with the tumor puts the patient at risk for catastrophic cerebral injury. Autogenous vein grafting is not always technically or physiologically possible. We present eight patients with tumors eroding the cranial base who underwent safe resection or occlusion of the internal carotid artery as predicted by three tests: 1. carotid arteriography, 2. temporary balloon occlusion of the internal carotid artery, and 3. xenon computerized tomography cerebral blood flow mapping. No patient suffered permanent central nervous system injury.