McGoron A J, Kassing W M, Thomas S R, Samaratunga R C, Pratt R G, Elson H R, Pipes D W
Department of Radiology, University of Cincinnati, Ohio, USA.
Cardiovasc Radiat Med. 1999 Oct-Dec;1(4):368-75. doi: 10.1016/s1522-1865(00)00032-9.
Optimization of intravascular radiation to reduce stenosis following coronary angioplasty requires the ability to predict the patterns of radiation dose distribution. This investigation evaluated the agreement between Monte Carlo simulations and experimental radiation dose measurements for a radioisotope liquid-filled balloon catheter in a tissue equivalent phantom.
Direct measurements of the radiation dose from Re-186 liquid-filled balloons were made using thermoluminescent dosimeters (TLDs) and radiochromic film. Monte Carlo simulations were carried out using the Monte Carlo N-Particle code system (MCNP4B).
The Monte Carlo generated dose values agreed with the experimentally determined results within the statistical uncertainty. A slightly higher penetration was indicated by regression analysis for the TLD data relative to the MCNP4B prediction that may be due to experimental configuration anomalies. For this balloon catheter, approximately 55 mCi of Re-186 will deliver 15 Gy at a 0.5 mm depth in tissue equivalent material in 5 min.
Correlation between experimentally measured dose values and Monte Carlo computation supports the position that MCNP4B simulations constitute a valuable tool for investigating various clinical therapy designs. The agreement between Monte Carlo calculations and experiments provide confidence in applying MCNP4B to more sophisticated geometries of interest, and other methods of intravascular radiation dose delivery.
优化血管内放射治疗以减少冠状动脉血管成形术后的狭窄，需要具备预测放射剂量分布模式的能力。本研究评估了在组织等效体模中，蒙特卡罗模拟与放射性同位素液体填充球囊导管的实验放射剂量测量结果之间的一致性。
使用热释光剂量计（TLD）和放射变色胶片对Re-186液体填充球囊的放射剂量进行直接测量。使用蒙特卡罗N粒子代码系统（MCNP4B）进行蒙特卡罗模拟。
蒙特卡罗生成的剂量值在统计不确定度范围内与实验确定的结果一致。相对于MCNP4B预测，TLD数据的回归分析表明穿透率略高，这可能是由于实验配置异常所致。对于这种球囊导管，约55 mCi的Re-186在5分钟内将在组织等效材料中0.5 mm深度处产生15 Gy的剂量。
实验测量的剂量值与蒙特卡罗计算之间的相关性支持了MCNP4B模拟是研究各种临床治疗设计的有价值工具这一观点。蒙特卡罗计算与实验之间的一致性为将MCNP4B应用于更复杂的感兴趣几何形状以及其他血管内放射剂量递送方法提供了信心。
