Reduction of Organ Absorbed Dose and Cancer Risk through Optimizing the Use of Projection in Diagnostic X-ray Examination

Abstract

This study aimed to calculate and compare the estimated organ absorption dose, risk of cancer due to exposure, and dose received by the gonads for women and men in radio diagnostic examinations with different projections. Radiographic examination of the abdomen (with anterior-posterior (AP) and posterior-anterior (PA) projections) and lumbar vertebrae (with anterior-posterior projection (AP), Right posterior-anterior oblique (RPO), and Left posterior-anterior oblique (LPO)), were performed. Software based on the Monte Carlo program has been used to calculate the estimated absorbed dose of the organ, the risk of cancer due to exposure, and the dose received by the gonads with different projections. The results showed that the PA projection on abdominal examination resulted in lower absorbed doses for the colon wall, liver, pancreas, and small intestine wall compared to the AP projection. The AP projection resulted in a higher absorbed dose than the oblique projection on the lumbar vertebral examination. RPO and LPO projections on lumbar spine examination produce different absorbed doses in organs. The colon wall, kidneys, pancreas, and prostate in men received lower doses using LPO, and the bladder, liver, ovaries (women), small intestine wall, and uterus in women received lower doses using projected RPO. The risk of cancer due to radiation exposure on abdominal examination is 35%-51% reduced using the PA projection, and on examination of the lumbar spine 40%-45% is reduced using the LPO projection. The dose received by the gonads showed that the ovarian dose reduction was 54% using the abdominal PA projection and 11% using the lumbar RPO. The dose reduction in the testicles was shown to be significant with the use of the abdominal PA projection.