Stereotactic radiosurgery, or SRS, is one of the fastest-growing radiation therapies, a technological innovation designed to target tiny tumors and other anomalies affecting the brain or spinal cord, while minimizing damage to surrounding tissue. Because the radiation is so concentrated and intense, accuracy is especially important. In the last five years, however, SRS systems made by Varian Medical Systems and its frequent German partner, Brainlab, have figured in scores of errors and overdoses, The New York Times has found. Medical physicists say there is nothing inherently wrong with linear accelerators that deliver general radiation therapy, as well as SRS. And, they say, the overdoses might have been caught had users followed a more rigorous system of checks and double-checks
