Calculation of patient dose and somatic dose index due to roentgen examinations

In order to estimate the risk involved in x-ray examination for an individual or for a population, doses resulting from x-ray examinations are needed for organs particularly sensitive to radiation, i.e., the thyroid gland, the lungs, the breasts, and the bone marrow. A dose calculation program is presented based on a semiempirical formula involving exposure, backscatter factor, relative depth dose, and off-axis attenuation. Results have been compared with experimental measurements and Monte Carlo calculations presented in the literature. Doses to any point, organ doses, energy imparted, and somatic dose index can be calculated in phantoms of different sizes. The agreement between these and Monte Carlo results is probably sufficient for radiation protection risk estimates.