Radiation safety in the era of helical CT: a patient-based protection program currently in place in two community hospitals in New Hampshire.

PURPOSE To describe a patient-based radiation safety program currently in place in 2 community hospitals in southern New Hampshire and the patients identified and managed by this program. METHODS The rationale, components, and early results of a patient-based radiation safety program are summarized and reviewed. The patient populations who may be affected by frequent exposure to helical CT scanning are identified both prospectively and retrospectively via a threshold approach using the number of studies the patient has had rather than attempting to directly measure radiation dose. This was arbitrarily defined as 5 studies of the neck, chest, abdomen, pelvis, or abdomen/pelvis in patients under 40 years of age with benign diagnoses, whose estimated exposure might approach 50 mSv. The mechanisms that can be put into place to prevent further exposure in these patients are discussed and outlined. RESULTS Fifty-four patients were initially identified over a 3-year period who had over 5 helical CT studies of the neck, chest, abdomen, pelvis, or abdomen/pelvis for benign diagnoses. An additional 104 patients were identified over a 12-year period by retrospectively "data mining" our radiology information system. A detailed program is outlined for the management of these patients, the future identification of patients, and the education of patients and providers. CONCLUSION Frequent exposure to possibly carcinogenic levels of ionizing radiation from helical CT scanning is a potentially large public health issue for the medical community. The identification and management of potentially at-risk patients is feasible.