Department of Otorhinolaryngology - Head and Neck Surgery, Turku University Hospital, Turku, Finland.
Department of Biomaterials Science, Institute of Dentistry and Turku Clinical Biomaterials Centre - TCBC, University of Turku, Turku, Finland.
J Appl Clin Med Phys. 2019 Dec;20(12):119-126. doi: 10.1002/acm2.12776. Epub 2019 Nov 29.
Radiation scattering from bone reconstruction materials can cause problems from prolonged healing to osteoradionecrosis. Glass fiber reinforced composite (FRC) has been introduced for bone reconstruction in craniofacial surgery but the effects during radiotherapy have not been previously studied. The purpose of this study was to compare the attenuation and back scatter caused by different reconstruction materials during radiotherapy, especially FRC with bioactive glass (BG) and titanium.
The effect of five different bone reconstruction materials on the surrounding tissue during radiotherapy was measured. The materials tested were titanium, glass FRC with and without BG, polyether ether ketone (PEEK) and bone. The samples were irradiated with 6 MV and 10 MV photon beams. Measurements of backscattering and dose changes behind the sample were made with radiochromic film and diamond detector dosimetry.
An 18% dose enhancement was measured with a radiochromic film on the entrance side of irradiation for titanium with 6 MV energy while PEEK and FRC caused an enhancement of 10% and 4%, respectively. FRC-BG did not cause any measurable enhancement. The change in dose immediately behind the sample was also greatest with titanium (15% reduction) compared with the other materials (0-1% enhancement). The trend is similar with diamond detector measurements, titanium caused a dose enhancement of up to 4% with a 1 mm sample and a reduction of 8.5% with 6 MV energy whereas FRC, FRC-BG, PEEK or bone only caused a maximum dose reduction of 2.2%.
Glass fiber reinforced composite causes less interaction with radiation than titanium during radiotherapy and could provide a better healing environment after bone reconstruction.
来自骨重建材料的辐射散射会导致愈合时间延长，甚至引发放射性骨坏死。玻璃纤维增强复合材料（FRC）已被引入颅面外科的骨重建，但之前尚未研究其在放射治疗中的作用。本研究的目的是比较不同重建材料在放射治疗过程中引起的衰减和背散射，特别是 FRC 与生物活性玻璃（BG）和钛。
测量了五种不同的骨重建材料在放射治疗过程中对周围组织的影响。测试的材料有钛、带和不带 BG 的玻璃 FRC、聚醚醚酮（PEEK）和骨。用 6 MV 和 10 MV 光子束照射样品。用放射色乳胶膜和钻石探测器剂量测定法测量样品背面的背散射和剂量变化。
在 6 MV 能量下，用放射色乳胶膜测量钛在照射入口侧的剂量增强了 18%，而 PEEK 和 FRC 分别引起了 10%和 4%的增强。FRC-BG 没有引起任何可测量的增强。与其他材料（增强 0-1%）相比，钛在样品后面立即引起的剂量变化也最大（减少 15%）。这一趋势与钻石探测器测量结果相似，钛在 1mm 样本时引起高达 4%的剂量增强，在 6 MV 能量下减少 8.5%，而 FRC、FRC-BG、PEEK 或骨仅引起最大 2.2%的剂量减少。
在放射治疗过程中，玻璃纤维增强复合材料与辐射的相互作用小于钛，并且在骨重建后可能提供更好的愈合环境。
