Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, 4669-2, Ami-machi, Inashiki-gun, Ibaraki, 300-3094, Japan.
Department of Radiation Therapy, Tsuchiura Kyodo General Hospital, 4-1-1, Ootsuno, Tsuchiura-city, Ibaraki, 300-0028, Japan.
Appl Radiat Isot. 2022 Aug;186:110301. doi: 10.1016/j.apradiso.2022.110301. Epub 2022 May 20.
In this study, we developed a mouthpiece-type gel dosimeter to prevent the oral mucositis caused by the perturbation effect of dental alloys in the radiotherapy of the head and neck regions and to enable in vivo dosimetry. Understanding the dose distribution in the oral cavity during radiotherapy helps identify the possible site for oral mucositis during treatment. Here agarose, which has a higher melting point than gelatin, was added as a coagulant to stabilize the shape of the dosimeter. The strength and dose response of the dosimeter were investigated. The strength was measured at room temperature, 20°C-40 °C, which is higher than the intraoral temperature. The dose-response curves were obtained by magnetic resonance imaging with R ranging from 0 to 25 Gy. The strength and dose response of the mouthpiece-type gel dosimeter were approximately 4 and 2.1 times higher than those of polyacrylamide gel and tetrakis hydroxymethyl phosphonium chloride dosimeters commonly used in the prescribed doses per fraction of treatment. The dosimeter is composed of 4 wt% MgCl and 1.5 wt% agarose; thus, it can retain the water equivalence. Through in vivo oral dosimetry in three dimensions for head and neck radiotherapy with dental alloys using the mouthpiece-type gel dosimeter, we obtained three-dimensional dose distributions in the dosimeter. The properties of the dosimeter show that it can be used in the clinic, depending on the prescribed dose.
在这项研究中，我们开发了一种口含式凝胶剂量计，以防止口腔黏膜的放射治疗中的牙科合金的扰动效应，并实现体内剂量测定。了解放射治疗过程中口腔内的剂量分布有助于确定在治疗过程中口腔黏膜炎可能发生的部位。在这里，我们添加了琼脂糖作为凝固剂，使其凝固点高于明胶，从而稳定剂量计的形状。我们研究了剂量计的强度和剂量响应。我们在室温下（20°C-40°C）测量了强度，该温度高于口腔内温度。通过磁共振成像获得了剂量响应曲线，其中 R 范围从 0 到 25Gy。与治疗过程中常用的聚丙酰胺凝胶和四羟甲基氯化磷剂量计相比，口含式凝胶剂量计的强度和剂量响应分别约高出 4 倍和 2.1 倍。剂量计由 4wt%MgCl 和 1.5wt%琼脂糖组成；因此，它可以保持水等效性。通过使用口含式凝胶剂量计对头颈部放射治疗中的牙科合金进行三维体内口腔剂量测定，我们获得了剂量计中的三维剂量分布。剂量计的性能表明，它可以根据规定的剂量在临床上使用。
