四种立体放射治疗技术的比较  

A Comparison of Four Sterotactic Radiotherapy Techniques

作　　者：姚原[1] 吴国华[1] 吴旭东[1] 张松方[1] 施飞[1] 林清[1] 

机构地区：[1]上海第二医科大学新华医院肿瘤放疗科,上海200092

出　　处：《上海第二医科大学学报》2002年第3期260-262,273,共4页Acta Universitatis Medicinalis Secondae Shanghai

摘　　要：目的 对二种不同形状的肿瘤靶区设野计算,比较四种立体放射治疗技术的剂量适形特点和正常组织受照剂量。方法 患者经过CT模拟定位后,行三维治疗计划勾画和计算。二个靶区,一个小而规则的肿瘤和一个大而不规则的肿瘤。用四种立体放射治疗技术对二靶区进行计算和比较:1.旋转治疗（ARC）:似传统的直线加速器的旋转治疗,用3～4个弧度;2.三维适形技术（3D）:用6个非共面固定野治疗;3.调强治疗（IMRTa）:用5个共面固定野和多叶光栅调强治疗;4.IMRTb:用6个非共面固定野和多叶光栅调强治疗。IMRT由反向治疗计划系统计算。每个靶区和每种技术都经过剂量容积直方图计算。结果 对小而规则的肿瘤,四种技术的剂量适形度和正常组织的等剂量分布基本相似,IMRTa相对更加出色。对大而不规则的肿瘤,在靶区剂量适形度上IMRTb表现最好;在正常组织的高/低剂量分布上IMRTa最好。结论 与ARC和3D相比,调强技术能提高靶区剂量的适形度和减少正常组织的高/低受照剂量和范围,用立体放射技术治疗大而不规则的肿瘤靶区,调强技术可以提高治疗率。The dose comformity and normal tissue isodose characteristics were compared by four stereotactic techniques of radiotherapy for two tumor target shapes. Methods Two test targets were constructed and calculated using a 3D treatment planning system after patients received CT simulation. The targets included a small regular tumor and a large irregular tumor. The stereotactic techniques were compared for each target: 1. Arc: 3 - 4 arcs as used in traditional linear radiotherapy. 2. Comformal therapy(3D): 6 fixed noncoplanar fields. 3. Intensity modulation radiotherapy(IMRT) a: 5 coplanar beams and a multileaf collimator. 4. IMRTb: noncoplanar beams and a multileaf collimator. IMRT were calculated using inversely - planned system. Dose volume histograms were performed for each target/technique combination. Results For the small regular tumor, dose conformity and normal tissue isodose distributions were similar in all four techniques, and IMRTa was more favorable than others. For the large irregular tumor, dose conformity was most favorable in IMRTb, and high/low isodose of normal tissue distribution was more favorable than IMRTa. Conclusion The intensity- modulated technique may improve dose conformity and decrease the dose for the normal tissue in a high/low isodose region as compared with the ARC and 3D technique. IMRT delivery may increase the therapeutic efficacy in treating large and irregularly shaped targets that were stereotactically defined.

关 键 词：肿瘤 立体放射治疗 放射疗法 CT 适形治疗 

分 类 号：R730.55[医药卫生—肿瘤]