Murakami Y, Nakashima T, Watanabe Y, Akimitsu T, Matsuura K, Kenjo M, Kaneyasu Y, Wadasaki K, Hirokawa Y, Ito K
Department of Radiology, Hiroshima University Graduate School of Medicine, Hiroshima 734-8551, Japan.
Phys Med Biol. 2007 Apr 21;52(8):2301-11. doi: 10.1088/0031-9155/52/8/017. Epub 2007 Apr 2.
We evaluated the basic properties of a commercially available BANGkit gel dosimeter, which is a normoxic type of BANG gel. This gel-kit has the same composition as the BANG 3 gel, but is fully oxygenated. To exclude oxygen, oxygen scavenging ascorbic acid and copper sulfate as a catalyst are used. The properties that we examined are the effects of the concentrations of copper sulfate and ascorbic acid on the response, the reproducibility, the long-term stability, the temperature effect at irradiation and the dose-rate effect. In our results, the excellent linear fit of the R2-dose response in a dose range for clinical use and its reproducibility were observed. The precision of a linear fit was preserved for about 3 weeks. The temperature at irradiation showed a significant effect on the dose response. Although the dose-rate dependence in the high-dose range was observed, it was negligible for the clinical dose range up to 270 cGy. In conclusion, this gel dosimeter is thought to be utilizable in clinical practice, while we have to pay attention to the temperature during the entire measurement processes, and additionally there is room for improvement in the linearity and the dose-rate dependence in the high-dose range.
我们评估了一种市售的BANGkit凝胶剂量计的基本特性，它是一种常氧型的BANG凝胶。这种凝胶试剂盒与BANG 3凝胶具有相同的成分，但已完全氧化。为了排除氧气，使用了抗坏血酸作为氧清除剂，并使用硫酸铜作为催化剂。我们研究的特性包括硫酸铜和抗坏血酸浓度对响应的影响、可重复性、长期稳定性、辐照时的温度效应以及剂量率效应。在我们的结果中，观察到在临床使用的剂量范围内R2剂量响应具有出色的线性拟合及其可重复性。线性拟合的精度保持约3周。辐照时的温度对剂量响应有显著影响。尽管在高剂量范围内观察到剂量率依赖性，但对于高达270 cGy的临床剂量范围而言可以忽略不计。总之，这种凝胶剂量计被认为可用于临床实践，同时我们在整个测量过程中必须注意温度，此外在高剂量范围内的线性和剂量率依赖性方面仍有改进空间。
