Lyra Maria, Lagopati Nefeli, Charalambatou Paraskevi, Vamvakas Ioannis
Radiation Physics Unit, A' Radiology Department, Kapodistrian University of Athens, 76 Vas Sophias Ave, Athens, Greece.
Radiat Prot Dosimetry. 2011 Sep;147(1-2):258-63. doi: 10.1093/rpd/ncr329. Epub 2011 Aug 9.
This study presents an attempt to compare individualised palliative treatment absorbed doses, by planar images data and Monte Carlo simulation, in two in vivo treatment cases, one of bone metastases and the other of liver lesions. Medical Internal Radiation Dose schema was employed to estimate the absorbed doses. Radiopharmaceutical volume distributions and absorbed doses in the lesions as well as in critical organs were also calculated by Monte Carlo simulation. Individualised planar data calculations remain the method of choice in internal dosimetry in nuclear medicine, but with the disadvantage of attenuation and scatter corrections lack and organ overlay. The overall error is about 7 % for planar data calculations compared with that using Monte Carlo simulation. Patient-specific three-dimensional dosimetric calculations using single-photon emission computed tomography with a parallel computed tomography study is proposed as an accurate internal dosimetry with the additional use of dose-volume histograms, which express dose distributions in cases with obvious inhomogeneity.
本研究试图通过平面图像数据和蒙特卡罗模拟，比较两例体内治疗病例（一例为骨转移，另一例为肝损伤）中个体化姑息治疗吸收剂量。采用医学内照射剂量方案来估算吸收剂量。还通过蒙特卡罗模拟计算了病变以及关键器官中的放射性药物体积分布和吸收剂量。个体化平面数据计算仍是核医学内剂量学的首选方法，但存在缺乏衰减和散射校正以及器官重叠的缺点。与使用蒙特卡罗模拟相比，平面数据计算的总体误差约为7%。建议使用单光子发射计算机断层扫描与平行计算机断层扫描研究进行患者特异性三维剂量计算，作为一种精确的内剂量学方法，并额外使用剂量体积直方图，其可表达明显不均匀情况下的剂量分布。
