A doctor who mistakenly operated on the healthy lobe of a cancer patient's brain, instead of the side with a tumor, was dismissed as head of neurosurgery at the Memorial Sloan-Kettering Cancer Center. Dr. Ehud Arbit pulled X-rays of another patient's skull before he operated May 26 on Rajeswari Ayyappan, the hospital said. It was the second surgical procedure Arbit had bungled in the past six months, the cancer center said. Ayyappan, who is the mother of Indian film star Sridevi, was transferred to New York Hospital within days of the mistake, and 40% of her tumor was removed during a second operation there. The 59-year-old woman was released from New York Hospital on July 18. Officials wouldn't say if she suffered any permanent damage.