A PC-Based Monte Carlo Program과 유리선량계를 이용한 장기선량 및 유효선량 평가

Evaluation of Organ and Effective Dose using A PC-Based Monte Carlo Program and Glass Dosimeter

Purpose : The purpose of this study is to examine the utility of PCXMC by comparing organ dose based on statistical data obtained from Monte Carlo of program and organ dose obtained from the method using phantom and glass dosimeter. Materials and Methods : 1. Direct method (the method of measurement using Glass Dosimeter) : GD3.52M (GD3.52M will be referred to as element ) is inserted in the center of each organ. To calculate HVL and entrance exposure dose(mR), Unfors Xi meter is attached to around center of phantom entrance surface. To calculate ESD, five elements were attached around fields. Chest PA, Chest Lat, L-spine AP, L-spine Lat, Pelvis AP, and Skull PA are irradiated as Protocol of this hospital. 2. indirect method (the method using PCXMC program) : PCXMC program minimizes Error (%) by entering the same parameter as direct method on the hypothetical mathematical phantom The same age, stature, weight, and Focus-Skin Distance as Examination data of RANDO phantom are input and the FOV is drawn in the very same position. 16 organ doses are compared and analyzed which are the same as glass dosimeter among 29 organ doses obtained from inputting doses in PCXMC. Results : 1. Organ doses : In all six tests, when comparing between PCXMC within FOV and others with organ doses in glass dosimeter, they are significant with each other (p<0.05). With relation to Out of FOV organ dose of Chest PA, Chest Lat, Pelvis AP, and Skull PA, the difference in terms of statistic is significant (p<0.05). 2. Effective dose : In Chest PA, and Chest Lat, effective dose using PCXMC is 0.0453, 0.1542 and effective dose using glass dosimeter is 0.0527, 0.1699 and shows the difference of 14% and 9% respectively. In Skull PA, organ dose using PCXMC program is 0.0209 and organic dose using glass dosimeter is 0.0209 and therefore they show the same result. In L-spine AP, and Lat, effective dose using PCXMC is 0.5635, 0.4794 and effective dose using glass dosimeter is 0.7845, 0.6301 and in other words, 28%, 23% respectively. The method of measurement using glass dosimeter is higher than that of measurement using PCXMC. In Pelvis AP, effective dose using PCXMC is 0.4709 and effective dose using glass dosimeter is 0.6833 and the difference is 31%. Conclusion : 1. Organ dose : In cases of organ dose using glass dosimeter and organ dose using PCXMC program and Chest PA, Chest Lat, Pelvis AP and Skull PA in which there is the difference of average, they are organ dose out of FOV and low dose. In case predose measurement value is less than 30uGy of organ dose, there is difference in measurement value in between organ dose using PCXMC program and organic dose using glass dosimeter. 2. Effective dose : In Chest PA, Lat, and Skull PA which show low effective dose, effective dose using PCXMC program and effective dose using glass dosimeter show similar result. In L-spine, Lat, and Pelvis AP with high effective, effective dose using glass dosimeter compared with effective dose using PCXMC program is measured high consistently.