Determination of individual S-values for 131I using segmented CT data and the EGS4 Monte Carlo code.
Determination of individual S-values for 131I using segmented CT data and the EGS4 Monte Carlo code.
复制标题
使用分段 CT 数据和 EGS4 蒙特卡罗代码确定 131I 的各个 S 值。
DOI：
10.1089/cbr.2005.20.98
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发表时间：
2005
影响因子：
3.4
通讯作者：
M. Schwaiger
中科院分区：
文献类型：
--
作者：
I. Wolf;M. Zankl;K. Scheidhauer;Eugenia Vabuliene;D. Regulla;C. von Schilling;M. Schwaiger
在从全身计算机断层扫描 (CT) 扫描中分割出来的单个体素模型中，使用 EGS4 蒙特卡罗代码计算 (131)I 的 S 值，并与医疗内辐射剂量 (MIRD) S 值进行比较，后者是根据理想化数学模型中的传输计算得出的。当将个体器官质量校正应用于 MIRD 值时，单独计算的 S 值与同时作为源和目标的器官的 MIRD 值非常一致。对于不同的源-目标组合，发现了高达 184% 的大偏差。然而，伽马吸收部分对总剂量的贡献很小（大约 4%）。因此，我们得出的结论是，放射性核素靶向治疗中的个体转运计算对于宏观剂量估计来说不是必需的。可靠的剂量测定被简化为准确测定体内活性的问题。
In individual voxel phantoms, which were segmented from whole-body computed tomography (CT) scans, S-values were calculated for (131)I using the EGS4 Monte Carlo code and compared to Medical Internal Radiation Dose (MIRD) S-values, which were derived from transport calculations in idealized mathematical phantoms. The individually calculated S-values agree very well with the MIRD values for organs, which are source and target simultaneously, when individual organ-mass corrections are applied to the MIRD values. For different source-target combinations, large deviations up to 184% were found. The contribution of the gamma-absorbed fractions to the total dose, however, is small ( approximately 4%). We conclude, therefore, that individual transport calculations in radionuclide-targeted therapies are not necessary for macroscopic dose estimates. Reliable dosimetry is reduced to the problem of accurate activity determination in vivo.