Researches On Hands Exposure Dose Of Interventional Radiology Procedure Employees

Objective:To learn the occupational exposure dose of hands in the interventional radiology procedures and the occupational exposure risk of interventional radiology workers. The factors that may affect the dose level were analysised in order to reduce the occupational radiation dose and to protect the staff of interventional radiology, then in future to provide the basis for the popularity, propaganda and training of the knowledge about how to reduce the dose of occupational exposure in the interventional radiology procedures.Methods:1.Selected4tertiary hospitals in Beijing city, utilized thermal dilution photodetector (ring dosimeter, LiF:Mg, TI) for measuring the radiation dose of the both hands of surgical staff during119cases of interventional operations, including57cases of coronary angiography (CA),24cases of percutaneous transluminal coronary angioplasty (PTCA)+stent implantation,15cases of radiofrequency ablation (RFA),14cases of pacemaker implantation (PM) and9cases of cerebral aneurysms intervention, measuring the accumulative doses for the same type of interventional operation, the same performer location and measurement site. Both hands of surgical staff wear a ring dosimeter during interventional operations and surgical staff including the primary surgeon, the second surgeon, the assistant and nurses.2. Among the4hospitals, a hospitals has27cases of CA, B hospital has30cases of CA, take measurement once per15cases. A hospital has18cases of PTCA+PCI, B hospital has16cases of PTCA+PCI, take measurement once per5cases. C hospitals has15cases of RFA, take measurement once per7cases, C hospital has14cases of PM, take measurement once per5cases, D hospitals has9cases of cerebral aneurysms intervention, take measurement once per3cases. After each interventional operation, record the voltage and current for fluoroscopy, fluoroscopy time, the numbers of photography, total cumulative dose, dose-area product, etc.3.In this study, we choose Hp (0.07) practical amount for hands-dose evaluation, according to the actual workload of each hospital, estimating the annual equivalent dose for the hands of surgical staff. Analyze the factors that may influence the radiation dose for surgical staff.Results:1. The results of the dose test:(1) During the interventional procedures, radiation dose for the left hand of the performer is significantly higher than the right hand. The radiation dose of the left hand for the primary surgeon of pacemaker implantation is the highest, while for the primary surgeon of cerebral aneurysms is the lowest. The doses for the hands of the primary surgeon were ranked as follow:pacemaker implantation radiofrequency ablation> coronary angiography> percutaneous transluminal coronary angioplasty> intervention procedure for cerebral aneurysms(2) The radiation doses for the hands of surgeons were different during different interventional operations, the primary surgeon> the second surgeon> the assistant> nurses.(3) The annual equivalent dose for the left hand of the primary surgeon was estimated as the average value, the highest annual equivalent doses for the left hand of the surgeon operated coronary angiography, percutaneous transluminal coronary angioplasty, radiofrequency ablation, cardiac pacemaker implantation and the interventional operation for cerebral aneurysms were:54mSv12.9mSv,33.7mSv,351.5mSv,14.9mSv, respectively; the annual equivalent doses of the right hand were22.3mSv,4.7mSv,12.5mSv,255.4mSv and10.1mSv, respectively. If the primary surgeon performed up to102surgeries during a year, utilized the maximum value for measurement, the annual equivalent dose for the hands of the primary surgeon would exceeded the limit value.2. Analysis of the influence factorsThe voltage for fluoroscopy, the total cumulative dose and dose-area product were collected, the correlations between the two variables were determined using a Spearman correlation analysis, these results were not statistically significant (P>0.05); the voltage for fluoroscopy, the current for fluoroscopy, fluoroscopy time, photography film and the numbers of photography, these results were statistically significant (the r values were:0.570,-0.711,0.564,-0.611and-0.711, respectively; the P values were0.026,0.003,0.028,0.035and0.035, respectively). Introduced the five variables into the multiple linear regression equation and using stepwise regression to fit into the equation, only fluoroscopy time and the number of photography were fit into the equation. The fitting equation was y=225.763+1.862x1-98.125x2, F=22.726, P=0.000. These results have shown that mainly affecting the radiation dose for the hands of the operator were fluoroscopy time and the number of Photography.Conclusion:1. For the different interventional procedures, the hand dose for the performers of pacemaker implantation was the highest (3.661mSv), while for the performers of cerebral angiography was the lowest (0.062mSv). With respect to the annual operations of these four hospitals, for performers of these five types of interventional operations, the highest hand annual dose was lower than the annual dose limit500mSv (according to our country’s GB18871)2. The average radiation dose for the hands of the surgeon who operated these five types of interventional operation was different, the average doses for the hands of the primary surgeon were ranked as follow:pacemaker implantation> radiofrequency ablation> coronary angiography> percutaneous transluminal coronary angioplasty> intervention procedure for cerebral aneurysms. The dose of the left hand was significantly higher than the right hand. The dose of the hands of the primary surgeon was the highest, followed by the second surgeon, the assistant and nurses. 3. After statistical analysis, our study found that fluoroscopy time and the numbers of photography have an effect on the hands dose of the performers, and also found that device operating conditions (the voltage and current for fluoroscopy, fluoroscopy time, photography voltage, photography width), the device output dose (total cumulative dose, dose-area product) and other factors have no effect on the hands dose of the performers.