The optimal radiation protective protocol of ceiling-suspended lead shield for interventional radiolo-gists:a phantom study / 介入放射学杂志

ABSTRACT

Objective To evaluate the radiation protective efficacy of different types and the positions of ceiling-suspended lead shield to the principal and assistant interventional operators in order to provide a scientific basis for the selection of optimal scheme in using ceiling-suspended lead shield.Methods At the principal and assistant interventional operators’ standing places the personal dose-measuring instruments were set up, which were placed at the height of 20 cm to 180 cm above the ground with an interval distance of 20 cm between each other.The postero-anterior (PA) projection and left lateral projection were used.The ceiling-suspended protection lead shields included lead glass (glass type) and lead glass with connected lead flexible stripe below (mixed type).The placed sites of the protection lead-shields were close to the principal operator, away from the principal operator, on the left side of the principal operator and close to the X-ray tube respectively.The radiation doses of PA projection and left lateral projection were determined.The real-time radiation dose rate and dose shielding rate at the nine measuring positions for the principal operator and assistant operator were separately calculated.The results were analyzed.Results The radiation protection of the glass type was slightly superior to that of the mixed type, but the difference was not significant.The principal operator was best protected when the shield was positioned close to him in the PA projection, and for left lateral projection the principal operator was best protected when the shield was positioned on his left side.For the assistant operator, the optimal protection was obtained when the shield was positioned close to him in both PA and left lateral projection.In the optimal position of ceiling-suspended lead shield, the highest radiation dose rate (0.71 mSv/h in glass group and 1.07 mSv/h in mixed group) was recorded on the principal operator at the height of 120 cm at PA projection, and higher radiation dose rate (≥0.47 mSv/h) was recorded on every point of both operators at the left lateral projection.Meanwhile, the overall received radiation doses of the two groups were very close.At the principal operator standing area, except for the position of 120 cm height (attenuation ratio 60.11% in glass group and 39.89% in mixed group), the attenuation ratio of each measuring point was above 93%.And the assistant operator standing area the attenuation ratio was 57%-97%.The lateral shielding ratio was generally slightly higher than PA shielding ratio.Conclusion The radiation protection effect of the two type shields is quite similar, both shields can obtain excellent protection efficacy.But the radiation dose at the height of 120 cm above the ground at PA projection is higher for the principal operator, while at lateral projection the radiation dose at all height levels is still relatively higher for both operators.Therefore, the radiation protection at the level of 120 cm height needs to be strengthened and the lateral projection exposure should be used as less as possible.