Medical physicists at last month's annual meeting of the American Association of Physicists in Medicine (AAPM) described the benefits of a new type of cancer radiotherapy treatment, Intensity Modulated Radiation Therapy (IMRT). Using computer control and a new accessory called dynamic multi-leaf collimator, IMRT was described as being able to focus higher doses of radiation on tumors while minimizing exposure to surrounding healthy tissue. "In time, HMOs will demand IMRT as a standard of care," predicts Radhe Mohan, director of radiation physics at the Medical College of Virginia Commonwealth University, Richmond. He described his use of IMRT on head and neck cancers at a symposium held in conjunction with AAPM meeting. Varian Associates Inc. a maker of radiotherapy products, sponsored the symposium.