Medical Physics Department, S. Orsola-Malpighi University Hospital, Bologna, Italy.
Med Phys. 2012 May;39(5):2491-8. doi: 10.1118/1.3702457.
To provide dose-area-product (DAP) to effective dose (E) conversion factors for complete interventional procedures, based on in-the-field clinical measurements of DAP values and using tabulated E/DAP conversion factors for single projections available from the literature.
Nine types of interventional procedures were performed on 84 patients with two angiographic systems. Different calibration curves (with and without patient table attenuation) were calculated for each DAP meter. Clinical and dosimetric parameters were recorded in-the-field for each projection and for all patients, and a conversion factor linking DAP and effective doses was derived for each complete procedure making use of published, Monte Carlo calculated conversion factors for single static projections.
Fluoroscopy time and DAP values for the lowest-dose procedure (biliary drainage) were approximately 3-fold and 13-fold lower, respectively, than those for the highest-dose examination (transjugular intrahepatic portosystemic shunt, TIPS). Median E/DAP conversion factors from 0.12 (abdominal percutaneous transluminal angioplasty) to 0.25 (Nephrostomy) mSvGy(-1) cm(-2) were obtained and good correlations between E and DAP were found for all procedures, with R(2) coefficients ranging from 0.80 (abdominal angiography) to 0.99 (biliary stent insertion, Nephrostomy and TIPS). The DAP values obtained in this study showed general consistency with the values provided in the literature and median E values ranged from 4.0 mSv (biliary drainage) to 49.6 mSv (TIPS).
Values of E/DAP conversion factors were derived for each procedure from a comprehensive analysis of projection and dosimetric data: they could provide a good evaluation for the stochastic effects. These results can be obtained by means of a close cooperation between different interventional professionals involved in patient care and dose optimization.
提供基于临床现场剂量面积乘积（DAP）值测量并利用文献中提供的单投影 E/DAP 转换因子表格，为所有介入操作提供 E/DAP 转换因子。
对 84 名患者的 9 种介入操作，在两种血管造影系统上进行。为每个 DAP 剂量仪计算不同的校准曲线（带和不带患者台衰减）。对每个投影和所有患者，现场记录临床和剂量学参数，并利用文献中单静态投影计算的蒙特卡罗转换因子，为每个完整操作推导一个将 DAP 与有效剂量联系起来的转换因子。
最低剂量操作（胆道引流）的透视时间和 DAP 值分别约为最高剂量检查（经颈静脉肝内门体分流术，TIPS）的 3 倍和 13 倍。获得了从 0.12（腹部经皮腔内血管成形术）到 0.25（经皮肾造瘘术）mSvGy(-1) cm(-2)的中位数 E/DAP 转换因子，并且对于所有操作都发现 E 与 DAP 之间存在良好的相关性，R(2) 系数范围从 0.80（腹部血管造影术）到 0.99（胆道支架植入术、经皮肾造瘘术和 TIPS）。本研究中获得的 DAP 值与文献中提供的值总体上一致，中位数 E 值范围从 4.0 mSv（胆道引流）到 49.6 mSv（TIPS）。
从投影和剂量学数据的综合分析中为每个操作推导了 E/DAP 转换因子的值：它们可以对随机效应进行很好的评估。这些结果可以通过不同介入专业人员之间的密切合作来获得，以参与患者护理和剂量优化。
