摘要
目的应用三维治疗计划系统(3D-TPS)比较研究食管癌的不同照射方法,评价常规三野等中心照射(RT)、三维适形(3D-CRT)、调强适形放射治疗(IMRT)在靶区剂量及正常组织保护方面的不同。方法采用三维治疗计划系统对12例经病理证实的中下段食管癌的患者CT定位图像分别设计3种放射治疗计划,分别为RT,3D-CRT,IMRT,计划的处方剂量均为50Gy,通过治疗计划及剂量体积直方图(DVH)比较靶区及危及器官剂量的差异。结果RT,3D-CRT,IMRT的95%计划靶体积(PTV)及95%大体肿瘤体积(GTV)的剂量有统计学意义,3D-CRT和IMRT优于RT;3种计划的靶区适形度指数、PTV剂量变异度指数、处方剂量覆盖GTV百分比均以IMRT计划为最好,3D-CRT、IMRT减少了双肺受照20Gy体积百分比(V20),均有统计学意义;3种计划的脊髓最大所受剂量、心脏1/3体积的所受剂量均在可耐受的范围内,IMRT为最小,P>0.05。结论3D-CRT、IMRT在靶区适形度和靶区剂量上均优于RT,能获得均匀的剂量分布,且能降低周围敏感器官的所受剂量,正常组织所受剂量均能在耐受范围内。
Objective To evaluate the contribution of three exposure methods comparising routine three field iso-center irradiation（RT）,three dimensional conformal radiotherapy（3D-CRT）and intensity medulated radiotherapy （IMRT） in the control of target area exposure dose and protection of porifocal normal tissues by using three dimensional treatment plan system （3D-TPS）.Methods Twelve patients with pathologically proved mid-lower esophageal carcinoma underwent RT,3D-CRT and IMRT with total dose of 50 Gy.Above three kinds of radiotherapoutic methods were designed based on CT locating images.The difference of exposure doses between target area and critical organ was compared by treatment plan（TP）and dose volume histogram（DVH）. Results There was significant difference in three doses of 95% plan target volume（PTV） and 95% gross tumor volume（GTV）（ P 〈0.05）, 3D-CRT and IMRT were better than RT. For three target conformal index and the prescription dose coverage of GTV porcentage,IMRT was the best plan. 3D-CRT and IMRT reduced lung V20（ P 〈0.05）.The maximum dose of spinal cord and 1/3 heart volume was limited into lerant range ,of them, IMRT was the smallest（ P 〈 0.05）. Conclusion For the target conformal degree and target dose ,3D-CRT and IMRT are superior to RT and can reduce the exposure dose of perifocal sensitive organs, simuhaneously,can limit the exposure dose of normal tissue into tolerant range.
出处
《实用医学影像杂志》
2008年第3期192-194,共3页
Journal of Practical Medical Imaging
关键词
食管癌
常规三野等中心照射
三维适形放射治疗
调强适形放射治疗
辐射剂量学
Esophageal carcinoma
Routine three field iso-center irradiation：3D-conformal radiotherapy
Intensity medulated radiotherapy
Radiation dosimetry
