Bochud François O, Laedermann Jean-Pascal, Baechler Sébastien, Bailat Claude J, Boschung Markus, Aroua Abbas, Mayer Sabine
Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland
Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland.
Radiat Prot Dosimetry. 2014 Dec;162(3):280-8. doi: 10.1093/rpd/nct336. Epub 2013 Dec 29.
Whole-body counting is a technique of choice for assessing the intake of gamma-emitting radionuclides. An appropriate calibration is necessary, which is done either by experimental measurement or by Monte Carlo (MC) calculation. The aim of this work was to validate a MC model for calibrating whole-body counters (WBCs) by comparing the results of computations with measurements performed on an anthropomorphic phantom and to investigate the effect of a change in phantom's position on the WBC counting sensitivity. GEANT MC code was used for the calculations, and an IGOR phantom loaded with several types of radionuclides was used for the experimental measurements. The results show a reasonable agreement between measurements and MC computation. A 1-cm error in phantom positioning changes the activity estimation by >2%. Considering that a 5-cm deviation of the positioning of the phantom may occur in a realistic counting scenario, this implies that the uncertainty of the activity measured by a WBC is ∼10-20%.
全身计数是评估发射伽马射线的放射性核素摄入量的首选技术。进行适当的校准是必要的，校准可通过实验测量或蒙特卡罗（MC）计算来完成。这项工作的目的是通过将计算结果与在拟人模型上进行的测量结果相比较，来验证用于校准全身计数器（WBC）的MC模型，并研究模型位置变化对WBC计数灵敏度的影响。计算使用GEANT MC代码，实验测量使用装载了几种放射性核素的IGOR模型。结果表明测量值与MC计算结果之间具有合理的一致性。模型定位1厘米的误差会使活度估计变化超过2%。考虑到在实际计数场景中模型定位可能出现5厘米的偏差，这意味着WBC测量活度的不确定性约为10% - 20%。
