Abstract
Data on the percentage depth-dose of diagnostic X-rays are important in evaluating patient dose from medical exposure. We developed a new method of calculating central-axis depth-dose in a homogeneous tissue phantom irradiated by diagnostic X-rays. First, primary and scattered components of percentage depthdose for mono-energetic X-rays were calculated by means of Monte Carlo simulation, and the data were stored in data tables. Then, percentage depth-doses for individual X-rays were calculated by making use of the data tables, the photon spectrum of X-rays, and exposure conditions such as field size. This method, which can calculate depth-dose under any condition of irradiation by combining with the approximating equation of the X-ray spectrum, is useful in evaluating the percentage depth-dose of diagnostic X-rays.
