Estimation of patient doses from selected fluoroscopy guided examinations based on Monte Carlo calculations (PCXMC)

Abstract

The aim of this work is to estimate organ and effective dose of patients during some selected fluoroscopy guided examinations using monte carlo based code PCXMC and propose conversion factors for dose estimation at the facility. Screening time, number of radiographs were recorded from the fluoroscopy console and the kerma area product (KAP) from a KAP meter for a total of one hundred and seventy-one (171) patients in two different facilities (A and B). Incident air kerma at reference point, organ and effective doses were estimated with PCXMC software. The mean KAP value was 11.0, 10.4 and 81.0 mGycm2 for hysterosalpingography (HSG), retrograde (RUG) and barium swallow (BaS) respectively. The estimated effective dose was 0.8, 1.1, 22.8 mSv for HSG, RUG and BaS respectively. The mean fluoroscopy screening time was 0.89, 1.26, 2.92 minutes for HSG, RUG and BaS respectively. The mean number of radiographs taken was 4.5, 7.0, 13.0 for HSG, RUG and BaS respectively. Bladder (7.96 mGy), testicles (21.89 mGy) and breast (76,77 mGy) received the highest dose for HSG, RUG and BaS respectively. The recorded mean KAP values of this study for BaS was high than that of HSG and RUG by a factor of 7.4 and 7.8 respectively. This was attributed to high number of radiographs taken and fluoroscopy screening time. The mean KAP of this study was more than that of other studies by a maximum factor of 22.0, 7.8 and 23.5 for HSG, RUG and BaS respectively. The fluoroscopy screening of this study was more than that of other studies by a maximum factor of 3.3, 4.7 and 10.3 for HSG, RUG and BaS respectively. Also, the mean number of radiographs taken for this study was more than that of other studies by a maximum factor of 2.0, 2.6 and 1.7 for HSG, RUG and BaS respectively. It was suggested that there are other contributing factors to patient doses in addition to the screening time and radiographs taken during fluoroscopy procedures. A dose conversion factor from measurable quantities to effective dose estimation has been proposed to aid patient dose optimization. Further studies aiming at reporting patient organ doses in fluoroscopy examination and investigate into other patient dose contributing factors has been recommended to strengthen patient dose optimization.