Cancer risks and radiation exposure from computed tomographic scans: how can we be sure that the benefits outweigh the risks?

摘要

THE INTRODUCTION OF THE COMPUTED TO-mographic (CT) scanner ushered in a new era of internal medicine diagnosis. Conditions that once required laparoscopy for diagnosis could now be diagnosed on the radiology reading board. The previously opaque anatomy of the living brain could now be visualized. The best part was that the test was "noninvasive," fast, and painless. With the exception of patients who were allergic to dye or had renal insufficiency, CT was considered completely safe. No wonder it had such a significant effect on the practice of medicine.Two articles in this issue of the Archives make us question if we have gotten carried away in our enthusiasm. Every day, more than 19 500 CT scans are performed in the United States, subjecting each patient to the equivalent of 30 to 442 chest radiographs per scan. Whether these scans will lead to demonstrable benefits through improvements in longevity or quality of life is hotly debated. What is becoming clear, however, is that the large doses of radiation from such scans will translate, statistically, into additional cancers. With CT scan use increasing annually, it is imperative that clinicians take into account the radiation risks when assessing the benefit to their patients.