Kato Mamoru, Chida Koichi, Nakamura Masaaki, Toyoshima Hideto, Terata Ken, Abe Yoshihisa
Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels - Akita, 6-10 Senshu-Kubota Machi, Akita, Akita, Japan.
Course of Radiological Technology, Health Sciences, Tohoku University Graduate School of Medicine, 2-1 Seiryo-cho, Sendai, Miyagi, Japan.
J Radiat Res. 2019 Mar 1;60(2):215-220. doi: 10.1093/jrr/rry110.
In a previous study, we reported on a novel (prototype) real-time patient dosimeter with non-toxic phosphor sensors. In this study, we developed new types of sensors that were smaller than in the previous prototype, and clarified the clinical feasibility of our newly proposed dosimeter. Patient dose measurements obtained with the newly proposed real-time dosimeter were compared with measurements obtained using a calibrated radiophotoluminescence glass reference dosimeter (RPLD). The reference dosimeters were set at almost the same positions as the new real-time dosimeter sensors. We found excellent correlations between the reference RPLD measurements and those obtained using our new real-time dosimeter (r2 = 0.967). However, the new type of dosimeter was found to underestimate radiation skin dose measurements when compared with an RPLD. The most probable reason for this was the size reduction in the phosphor sensor of the new type of dosimeter. We believe that, as a result of reducing the phosphor sensor size, the backscattered X-ray irradiation was underestimated. However, the new dosimeter can accurately determine the absorbed dose by correcting the measured value with calibration factors. The calibration factor for the new type dosimeter was determined (by linear regression) to be ~1.15. New real-time patient dosimeter design would be an effective tool for the real-time measurement of patient skin doses during interventional radiology treatments.
在之前的一项研究中，我们报道了一种带有无毒磷光传感器的新型（原型）实时患者剂量仪。在本研究中，我们开发了比之前原型更小的新型传感器，并阐明了我们新提出的剂量仪的临床可行性。将新提出的实时剂量仪获得的患者剂量测量值与使用校准后的放射光致发光玻璃参考剂量仪（RPLD）获得的测量值进行比较。参考剂量仪设置在与新型实时剂量仪传感器几乎相同的位置。我们发现参考RPLD测量值与使用我们的新型实时剂量仪获得的测量值之间具有极好的相关性（r2 = 0.967）。然而，与RPLD相比，发现新型剂量仪低估了辐射皮肤剂量测量值。最可能的原因是新型剂量仪的磷光传感器尺寸减小。我们认为，由于磷光传感器尺寸减小，背散射X射线照射被低估。然而，新型剂量仪可以通过用校准因子校正测量值来准确确定吸收剂量。新型剂量仪的校准因子（通过线性回归）确定为~1.15。新型实时患者剂量仪设计将成为介入放射治疗期间实时测量患者皮肤剂量的有效工具。
