In 1976, Bill Edge had earned an MS in nuclear engineering at the Georgia Institute of Technology and was working on his doctorate when a friend called to offer him a position at a hospital. A hospital? "I'd done some work at Oak Ridge in health physics," says Mr. Edge, "which is really a safety areamaking sure people aren't exposed to radioactivity. But most health physics jobs were in nuclear reactors, and after Three Mile Island they just weren't being built any more. And I wanted to do something more interesting and more useful. So I moved over to the medical area. I have a good bit of clinical contact with patients, so I know I am doing something useful, and the work gets more interesting all the time." For the last 13 years, he has been director of the radiation-physics department at Northeast Georgia Medical Center in Gainesville. His work includes planning computerized radiation treatments, making physics measurements on equipment used to treat patients, and serving as a liaison between physicians, dosimetrists, and therapists. As radiation safety officer, he also ensures the safety of the treatment machines and generates tables to be used in treatment calculations. Now he is preparing to accept a three-dimensional planning system that uses data from computed tomography to plan patient treatments with 3-D graphics presentation of patient anatomy and treatment beams. Mr. Edge is technically a therapeutic radiation physicist, which represents a combination of radiation physics and medical therapy. This is distinct from a radiation therapist, who administers treatment to patients, and a radiation oncologist, who is an MD who has overall responsibility for patients' treatment. He does not feel that a PhD is necessary for his work; instead, the essential degree is a master's in physics, ideally accompanied by one of the programs accredited by the American Association of Physicists in Medicine (AAPM). These programs, most of them offered at large teaching hospitals, combine classroom and clinical work. "You can get into this field the way I did: Work under someone who is already certified as a therapeutic radiation physicist and gain your experience on the job. But one way or another you need the right medical background. And that's where the AAPM programs are just right." "I have also found that certification is an asset in this field. After working for 3 years, a medical physicist is eligible to stand for boards in his area, such as therapy physics, diagnostic physics, or nuclear medicine physics. I am presently board certified by the American Board of Radiology (ABR), the American Board of Medical Physics (ABMP), and the American Board of Science in Nuclear Medicine (ABSNM). Most of the job listings today are requesting board certification, and some fields, such as mammography, are requiring certification in order to do equipment calibrations."