Comparative study of dose distribution between carbon ion radiotherapy and photon radiotherapy for head and neck tumor
Comparative study of dose distribution between carbon ion radiotherapy and photon radiotherapy for head and neck tumor
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DOI：
10.1007/s11604-008-0252-9
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发表时间：
2008-08-01
影响因子：
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通讯作者：
Tsujii, Hirohiko
中科院分区：
文献类型：
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作者：
Islam, M. Amirul;Yanagi, Takeshi;Tsujii, Hirohiko
目的.一项比较治疗计划的研究已经进行了碳离子放疗（CIRT）和光子放疗[三维适形放疗（3D-CRT）和调强放疗（IMRT）]，以评估潜在的改善和局限性，可能导致局部晚期，不可切除的头颈部肿瘤。随机选择7名最初接受CIRT治疗的患者进行比较研究。采用剂量-体积直方图参数、符合性指数、不均匀性系数和危及器官剂量（OARs）进行评价。3D-CRT、IMRT和CIRT的平均符合性指数分别为1.46、1.43和1.22。3D-CRT、IMRT和CIRT的平均不均匀系数分别为0.05、0.07和0.02。与相应的碳离子计划相比，光子计划在10%至95%的等剂量水平下产生更大的正常组织体积，其中3D-CRT的体积增加了1.2至2.7倍，IMRT的体积增加了1.2至2.0倍。与3D-CRT和IMRT相比，CIRT具有改善靶区剂量符合性、不均匀系数和OAR保留的潜力。与3D-CRT相比，使用IMRT主要在中低等剂量水平减少正常组织照射。使用CIRT获得了额外的改善。
Purpose. A comparative treatment planning study has been performed between carbon ion radiotherapy (CIRT) and photon radiotherapy [three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT)] to assess the potential improvements and limitations that could result for locally advanced, nonresectable head and neck tumors.Materials and methods. Seven patients, originally treated with CIRT, were randomly selected for the comparative study. The evaluations analyzed using dose-volume histogram parameters, conformity index, inhomogeneity coefficient, and dose to the organs at risk (OARs).Results. The mean conformity index was 1.46, 1.43, and 1.22 for 3D-CRT, IMRT, and CIRT, respectively. The mean inhomogeneity coefficient was 0.05, 0.07, and 0.02 for 3D-CRT, IMRT, and CIRT respectively. Photon plans resulted in greater volumes of normal tissues at 10% to 95% isodose levels compared with the corresponding carbon ion plans where the volumes increased by a factor of 1.2 to 2.7 for 3D-CRT and 1.2 to 2.0 for IMRT.Conclusion. CIRT has the potential to improve the target dose conformity, inhomogeneity coefficient, and OAR sparing when compared with 3D-CRT and IMRT. Compared with 3D-CRT, normal tissue exposure was reduced mainly in the mid- to low-isodose levels using IMRT. Additional improvement was obtained using CIRT.