Purpose: Calculation of conversion coefficients for the reconstruction of organ doses from entrance doses for chest radiographs of 0, 1, 5, 10, 15, and 30-year-old patients in conventional pediatric radiology for the radiographic settings recommended by the German and European guidelines for quality management in diagnostic radiology.
Materials and methods: The conversion coefficients for pediatric chest radiographs were calculated using the commercially available personal computer program PCXMC developed by the Finnish Centre for Radiation and Nuclear Safety (Säteilyturvakeskus STUK). PCXMC is a Monte Carlo program for computing organ and effective doses in about 40 organs of mathematical hermaphrodite phantom models describing patients of different ages. The possible clinical variation of beam collimation was taken into consideration by defining optimal and suboptimal radiation fields on the phantoms' surfaces.
Results: Conversion coefficients for the reconstruction of organ doses from measured entrance doses during chest radiographs for 0, 1, 5, 10, 15, and 30-year-old pediatric patients were presented. Conversion coefficients were calculated for the standard sagittal and lateral beam projections and the standard focus film distances of 100 cm, 115 cm, and 150 cm using the standard radiation qualities according to the recommendations of the German and European guidelines for quality management in diagnostic radiology. These conversion coefficients allow the reconstruction of the absorbed dose in about 40 organs and tissues of the human body for optimal and suboptimal radiation field collimations.
Conclusion: The conversion coefficients presented in this paper may be used for organ dose assessments from entrance doses measured during chest radiographs of patients of all age groups with all beam collimations within optimal and suboptimal standard beam collimations. While the influence of the beam collimation on organ doses of organs localized near the center of the beam is expectedly low, the radiation exposure of organs and tissues near the boundaries of the radiation field can be considerably reduced by an optimal beam collimation. The conversion coefficients calculated for the STUK phantoms are in good conformity with values published for the GSF phantoms "Adam", "Golem" and "Visible Human".