心脏介入患者受照剂量研究

Survey on patient dose in cardiac intervention

目的调查我院心脏介入诊疗过程中患者受照剂量分布和剂量参考水平,并分析各种剂量参数如皮肤峰值剂量(PSD)和剂量面积乘积(DAP)之间的相关性。方法对135例患者的剂量数据进行分析研究,其中接受冠状动脉造影(CAG)患者84例,接受经皮心脏介入(PCI)患者51例。记录每例患者DAP值、参考点累计剂量值(CD)以及透视时间,总采集图像幅数。采用热释光剂量片(TLD)矩阵测量患者皮肤剂量。TLD矩阵大小为10行9列,行间隔5cm,列间隔4cm。结果对于PCI,DAP均值为7946.91μGym2;CD均值为1395.3mGy,平均透视时间10.9min,平均采集945幅。PSD范围为38.91～184.79mGy。DAP与PSD的相关性为0.54,PSD与CD的相关性为0.53。对于CAG,DAP均值为2690.84μGym2;CD均值为431.6mGy,平均透视时间为2.9min,平均采集544幅。PSD范围26.18～120.37mGy。DAP与PSD的相关性为0.52,PSD与CD的相关性为0.45。结论患者所受皮肤剂量峰值低于所致皮肤损伤辐射阈值(2Gy)。各种辐射剂量参数(如DAP,CD和透视时间等)的结果与其他学者的研究结果相仿。从结果可以看出PSD与DAP、CD等参数相关性较差,因此基于这些数据对个体皮肤峰值剂量进行估算的方法较不科学,需要对其进一步研究。

Objective To collect information of patient doses of interventional radiology in Beijing Xuanwu Hospital, and investigate correlation between the peak skin dose （PSD） and dose-area product （DAP）. Methods Radiation doses from 135 patients have been studied including 84 coronary angiographies （CAG） and 51 percutaneous transluminal coronary angioplasties （PCI）. Dose-area product （DAP） values, cumulative dose （CD） at interventional reference points, fluoroscopy times, total number of cine frames were collected for each patient. Skin dose measurements were made with thermoluminescent dosimeters （TLD） placed as a 10 - 9 arrays of TLDs on the body. The grid of TLDs arrays was 5 x 4 cm. Results Mean values for dose-area product were 2690.84 μGym^2 for CAG and 7946.91 μGym^2 for PCI. Mean values for CD were 431.6 mGy cm^2 for CAG and 1395.3 mGy for PCI. Mean fluoroscopy times were 2.9 rain for CAG and 10.9 rain for PCI and mean number of frames were 544 and 945 for CAG and PCI, respectively. PSD values ranged from 26.18 to 120.37 mGy for CAG and 38.91 to 184.79 mGy for PCI. The relationship between DAP and PSD was r ： 0.52 for CAG and r = 0.54 for PCI. The correlation of PSD with CD was r = 0.45 for CAG and r = 0.53 for PCI. Conclusion Comparison shows that patients DAP, CD and fluoroscopy time values were comparable with other publications. Skin dose values of investigated patients are below the threshold dose for radiation skin injury （2 Gy）. There is no good relationship between DAP and PSD. So calculation of individual maximum skin dose based on DAP data is not reliable and needs to find a new reference value for skin dose. （J Intervent Radiol, 2007, 16： 222-225）