Comparison of simulation and direct measurement methods for detennining neonatal radiographic organ doses

Abstract

Patients in the neonatal intensive care unit receive numerous radiographic examinations for both diagnostic and follow up purposes such as pneumonias, respiratory distress syndrome, meconium aspirate, and cardiac anomalies, to name a few. There is concern with radiation-induced cancer development especially in pediatric patients due to smaller size, higher rate of mitotic cell division, and longer life expectancy. Although radiation dose from a single x-ray radiograph is low, we need to consider the effects of cumulative examinations. Organ doses cmmot be measured directly in patients, but can be estimated using computer simulations or laboratory measurements. One commonly used computational method is the PCXMC 2.0 software, which uses Monte Cm'lo simulations of photon propagation in tissue to calculate an estimated dose. The doses calculated by this program have been compared with doses measured using physical phantoms and doses measured on the surface of patients. This research project will compare the PCXMC 2.0 organ doses with organ doses measured from the ATOM 703-D phantom as well as organ doses measured from pediatric cadavers, a method yet to be found in the literature. The student will use thennoluminescence dosimeters (TLDs) to measure the organ doses. The objectives for the student would be to learn radiological physics as well as experimental techniques, have clinical exposure, pmticipate in an interdisciplinary team, learn to use the software progran1 PCXMC 2.0, TLDs, and x-ray machines to calculate and measure doses, and to recognize and appreciate patient safety in the field of pediatric radiology.