用胶片法对心脏介入程序中患者峰值皮肤剂量测量研究

目的 采用胶片法对进行心血管介入手术中患者所受峰值皮肤剂量（PSD）进行测量研究，包括冠状动脉血管造影术（CA）和经皮穿刺腔内冠状动脉成形术（PTCA）。方法 选用Gafchromic XR-RV3胶片在两家医院进行患者峰值皮肤剂量的测量。手术时将胶片放在患者身下的诊视床上。记录手术中监视器上显示的kV、mA、透视时间、剂量面积乘积（DAP）、参考点累积剂量等相关信息。采用Epson V750平板扫描仪对胶片进行分析扫描及分析，选用FilmQA软件分别测量图像的红、绿、蓝三色通道的像素值，使用红通道数据计算患者的 PSD。对PSD与设备显示参数进行相关分析，对相关的变量进行多元线性回归分析。结果 共测量CA手术26例，CA+PTCA手术19例。CA手术中，透视时间最高为17.62 min，累积剂量和DAP最大分别为1 498.50 mGy和109.68 Gy ·cm²，PSD最大为361.20 mGy。CA+PTCA手术中，曝光时间最长为64.48 min，累积剂量和DAP最大分别为6 976.20 mGy和5 336.00 Gy ·cm²，17例患者的PSD在1 Gy以内，1例患者PSD在1~2 Gy之间，1例患者PSD超出了发生皮肤损伤2 Gy的阈值，达到了2 195.70 mGy。CA程序中，患者PSD与DAP相关（R²=0.815，P<0.05），CA+PTCA程序中，患者PSD与累积剂量相关（R²=0.916，P<0.05）。结论 心脏介入放射学程序中部分患者的PSD会超出ICRP建议的发生皮肤确定性效应的2 Gy阈值。DSA设备上显示的剂量相关的参数，只能粗略估算患者PSD的大小。使用XR-RV3胶片精确测量介入手术中患者的峰值皮肤剂量是一种非常快捷、有效的方法。

Peak skin dose measurements in two cardiac interventional procedures using radiochromic film

Objective To measure the peak skin dose (PSD) in two cardiovascular interventional procedures, including coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA) using radiochromic film. Methods Gafchromic XR-RV3 film was selected to measure PSD in two hospitals. The films were placed on the table underneath the patient during interventional surgery. The kV, mA, fluoroscopy time, dose-area product (DAP), and cumulative dose at reference point and other relevant information were recorded for all cases. Using the Epson V750 flatbed scanner for scanning and analyzing film,FilmQA software was chosen to analyze the pixel value of red, green and blue color channels. The PSD was determined using red channel data. The correlation and linear regression analysis between PSD and device-displayed parameters was carried out. Results PSD were measured using XR-RV3 film for 26 CA and 19 CA+PTCA procedures. For CA procedures, maximum fluoroscopy time, cumulative dose and DAP were 17.62 min, 1 498.50 mGy and 109.68 Gy ·cm², respectively. The maximum PSD was 361.20 mGy. However, for CA+PTCA procedures, maximum fluoroscopy time, cumulative dose and DAP were 64.48 min, 6 976.20 mGy and 5 336.00 Gy ·cm², respectively. One patient with CA+PTCA procedures was found to have received the PSD value more than 2 Gy, up to 2 195.70 mGy. DAP was found to be a good indicator (R²=0.815,P<0.05) of PSD for CA procedure, and correlated with cumulative dose (R²=0.916,P<0.05) for CA+PTCA procedures. Conclusions The PSD value of some patients in cardiac interventional procedures would exceed 2 Gy, the threshold of deterministic effects recommended by ICRP. The dose-related parameters value showed on DSA device can only used to estimate PSD roughly. Using XR-RV3 film accurate measurement of the PSD in interventional projects is a very fast and effective method.