Nanoparticles with a high atomic number are of interest as radiosensitizers for radiation therapy of cancer. A variety of nanoparticles and radiation sources makes the challenge of selecting their optimal combinations to achieve maximum irradiation efficacy relevant. In this work, we calculated the values of the dose enhancement factors of elemental compositions of metal oxide nanoparticles (Al₂O₃, TiO₂, MnO₂, Fe₂O₃ and Fe₃O₄, NiO, GeO₂, ZrO₂, CeO₂, Gd₂O₃, Tm₂O₃, HfO₂, Ta₂O₅, and Bi₂O₃), as well as GeO₂ and HfO₂ doped with the rare-earth elements lanthanum or ytterbium in combination with monochromatic photons (1–500 keV) and X-ray radiation corresponding to the radiation of kilovoltage X-ray therapy machines. At a nanoparticle concentration of 10 mg/mL, the maximum values of the dose enhancement factors were from 1.03 to 2.55 for monochromatic radiation and from 1.01 to 2.33 for the studied X-ray spectra. Doping GeO₂ with 20% lanthanum or ytterbium led to an increase in the maximum value of dose enhancement factors by ~10%. Doping HfO₂ did not lead to significant changes in the value of dose-enhancement factors. Thus, all studied elemental compositions of nanoparticles, with the exception of Al₂O₃ (a dose enhancement factor ~1.02), are promising for application in kilovoltage X-ray radiotherapy. At the same time, the complex dependence of dose enhancement factors on the spectral composition of X-ray radiation requires detailed studies of the impact of irradiation conditions on the magnitude of the radiomodifying effect of nanoparticles.

具有高原子序数的纳米颗粒作为用于放射疗法治疗癌症的放射增敏剂是令人感兴趣的。各种各样的纳米粒子和辐射源对选择它们的最佳组合以实现最大的辐射功效提出了挑战。在这项工作中，我们计算了金属氧化物纳米粒子（Al ₂ O ₃，TiO ₂，MnO ₂，Fe ₂ O ₃和Fe ₃ O ₄，NiO，GeO ₂，ZrO ₂， CeO ₂，Gd ₂ O ₃，Tm ₂ O ₃，HfO ₂，Ta ₂ O ₅和Bi ₂ O ₃），掺有稀土元素镧或rare的GeO ₂和HfO ₂以及单色光子（1-500 keV）和X射线辐射对应于千伏X射线治疗仪的辐射。在10 mg / mL的纳米颗粒浓度下，单色辐射的剂量增强因子最大值为1.03至2.55，而研究的X射线光谱的剂量增强因子最大值为1.01至2.33。用20％的镧或y掺杂GeO ₂导致剂量增加因子的最大值增加了约10％。掺杂HfO ₂并未导致剂量增加因子的值发生显着变化。因此，除Al ₂ O ₃（剂量增强因子〜1.02）外，所有研究的纳米粒子元素组成都有望用于千伏X射线放射治疗。同时，剂量增强因子对X射线辐射光谱成分的复杂依赖性要求对辐照条件对纳米粒子的放射修饰作用强度的影响进行详细研究。