常见固定义齿对放疗剂量分布影响的模拟研究  

A SIMULATION STUDY ON THE INFLUENCE OF COMMONLY USED FIXED DENTURES ON RADIOTHERAPY DOSE DISTRIBUTION

作　　者：刘宏 黄顺平[1] 肖杨 李恒 吴艳[1] 张雅倩 LIU Hong;HUANG Shunping;XIAO Yang;LI Heng;WU Yan;ZHANG Yaqian(Tumor Center, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 401336, China)

机构地区：[1]重庆医科大学附属第二医院肿瘤中心,重庆401336

出　　处：《精准医学杂志》2021年第4期291-294,共4页Journal of Precision Medicine

基　　金：重庆市科卫联合医学科研项目(2019MSXM024)。

摘　　要：目的比较4种常见固定义齿在放射治疗中对剂量分布的影响。方法分别将4种固定义齿模型置于均匀组织模体中,基于蒙特卡罗方法进行模拟计算放疗剂量分布,通过特定范围百分深度剂量(PDD)与离轴曲线(Profile)分析,比较义齿与正常牙齿在周围软组织中剂量分布差异。结果钛合金义齿对上方组织放射剂量分布影响最大,钴铬合金义齿对下方组织放射剂量分布影响最大,钛合金义齿对侧方组织放射剂量分布影响最大。相对于正常牙齿,钛合金义齿、氧化锆全瓷牙、钴铬合金义齿、镍铬合金义齿使上方组织的放射剂量分别升高了14.2%、11.2%、9.6%、9.2%;氧化锆全瓷牙、钛合金义齿、镍铬合金义齿、钴铬合金义齿使下方组织放射剂量分别减少了17.5%、15.9%、22.9%、23.1%;氧化锆全瓷牙、钛合金义齿、镍铬合金义齿、钴铬合金义齿使侧方组织的放射剂量分别升高了2.0%、4.1%、2.4%、1.4%。义齿对射野中心轴方向影响较大,在模体下1.9与3.1 cm处发生剂量跃变。结论4种固定义齿在相同条件下相较于正常牙齿对剂量分布影响最大为钛合金义齿,其次为镍铬合金义齿和钴铬合金义齿,对剂量分布影响最小为氧化锆全瓷牙。在临床治疗计划中应避免或减少穿过固定义齿的射野,必要时需针对不同材料义齿对放射剂量分布影响进行分析,以降低相关治疗风险。Objective To investigate the influence of four commonly used types of fixed denture on radiotherapy dose distribution.Methods The models of the four types of fixed denture were placed in a uniform tissue phantom,and simulation calculation of radiotherapy dose distribution was performed based on the Monte Carlo method.Percentage depth dose(PDD)and off-axis curve(Profile)were analyzed to compare the difference in dose distribution in the surrounding soft tissue between dentures and normal teeth.Results Titanium alloy denture had the greatest influence on radiotherapy dose distribution in the tissue above the denture;the cobalt-chromium alloy denture had the greatest influence on radiotherapy dose distribution in the tissue below the denture;titanium alloy denture had the greatest influence on radiotherapy dose distribution in the lateral tissue.Compared with normal tooth,titanium alloy denture,zirconia all-ceramic denture,cobalt-chromium alloy denture,and nickel-chromium alloy denture increased the radiotherapy dose in the tissue above the denture by 14.2%,11.2%,9.6%,and 9.2%,respectively;zirconia all-cera-mic denture,titanium alloy denture,nickel-chromium alloy denture,and cobalt-chromium alloy denture reduced the radiotherapy dose in the tissue below the denture by 17.5%,15.9%,22.9%,and 23.1%,respectively;zirconia all-ceramic denture,titanium alloy denture,nickel-chromium alloy denture,and cobalt-chromium alloy denture increased the radiotherapy dose in the lateral tissue by 2.0%,4.1%,2.4%,and 1.4%,respectively.The denture had a great influence on the direction of the central axis of the radiation field,and dose jumps were observed at 1.9 cm and 3.1 cm in the phantom.Conclusion Among the four types of fixed denture,titanium alloy denture has the greatest influence on dose distribution under the same conditions,followed by nickel-chromium alloy denture and cobalt-chromium alloy denture,and zirconia all-ceramic denture has the slightest influence on dose distribution.In clinical treatment planning,radiation field t

关 键 词：蒙特卡罗法 放射疗法 义齿 牙科合金 放射治疗计划 计算机辅助 辐射剂量 

分 类 号：R814.2[医药卫生—影像医学与核医学] R815[医药卫生—放射医学]