This article on New Scientist and this article on Yahoo (Reuters) and this article on Wired (and probably many other news sites) talks about PathFinder a London robot brain surgeon. A surgeon looks at the brain scan and tells the robot where to work (like the surgeon sort of points out a tumor). The PathFinder robot then uses CT scan images and some titanium locations markers to help it locate where to position it's robot arm to do simple tasks like pushing a tiny needle instrument into an entry point and holding it steady at the tumor site while the surgeon takes a biopsy. In the future the robot will be expected take biopsies on it's own.