Metal-polysiloxane shields for radiation therapy of maxillo-facial tumors.
Metal-polysiloxane shields for radiation therapy of maxillo-facial tumors.
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用于颌面部肿瘤放射治疗的金属聚硅氧烷防护罩。
DOI：
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发表时间：
1991
期刊：
影响因子：
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通讯作者：
W. Mclaughlin
中科院分区：
文献类型：
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作者：
M. Farahani;F. Eichmiller;W. Mclaughlin
在用高强度辐射(远程治疗)治疗一些头颈部病变时，一个基本的过程是应用一个单独定制的屏蔽装置，它被设计、建模并形成一个有效的口腔外或口腔内支架，目的是保护健康组织。目前的技术水平是缓慢和技术密集的，这会增加患者在成型和制造过程中的不适和不便。描述了一种新的配方，它提供了快速和容易地形成可模塑复合支架，特别是用于口腔内使用。校准的辐射变色薄膜条和软组织模拟塑料(聚苯乙烯)层的交错堆叠提供了一种使用配备凝胶扫描仪或扫描激光显微密度计的分光光度计绘制高密度屏蔽材料附近的一维或二维剂量分布分布图的方法。为了测量模拟组织聚合物与复合支架材料界面附近的剂量分布，用60Co远距治疗机的准直伽玛射线束进行了测量。这些结果表明，由柔性树脂和高浓度球形金属合金粉末组成的快速形成的复合材料提供了有效的定制设计的屏蔽，并且由于树脂的薄层不含金属，减少了对正常组织的背向散射辐射剂量。成功配方的一个例子是在乙烯基聚硅氧烷树脂中混合90%重量百分比的银铜合金粉末。这种材料是一种可模塑的油灰，聚合后形成刚性弹性材料，为来自60Co源的伽马射线束提供大约2.5至2.8厘米的半值层。
In the treatment of some head and neck lesions with high-intensity radiation (teletherapy), an essential procedure is the application of an individually customized shielding appliance, which is designed, modeled, and formed into a working extra- or intraoral stent for the purpose of sparing healthy tissues. The present state of the art is slow and technique intensive, which can add to patient discomfort and inconvenience during molding and fabrication. A new formulation is described, which offers speed and ease of forming a moldable composite stent especially for intraoral use. Interleaved stacks of calibrated thin radiochromic film strips and soft-tissue-simulating plastic (polystyrene) layers gave a means of mapping one- or two-dimensional profiles of dose distributions adjacent to the high-density shielding materials using a spectrophotometer equipped with a gel scanner or a scanning laser-beam microdensitometer. Tests using collimated gamma-ray beams from a 60Co teletherapy unit were made in order to measure the dose distribution near interfaces of tissue-simulating polymer and the composite stent material with and without mixtures of metals (Ag-Cu and Sn-Sb). These results show that quickly formed composites made of a flexible resin with high concentrations of powdered spherical metal alloys provide effective custom-designed shielding, and, with a thin overlayer of the resin without metal, a diminished back-scattered radiation dose to normal tissues. An example of a successful formulation is a mixture of 90% by weight Ag-Cu alloy powder in a vinyl polysiloxane resin. This material is a moldable putty which, upon polymerization, forms a rigid elastomeric material, providing a half-value layer of approximately 2.5 to 2.8 cm for a gamma-ray beam from a 60Co source.