调强适形放射治疗在临床的应用

目的：介绍调强适形放射治疗（intensity modulated radiation therapy,IMRT）在美国Stanford大学医学中心放疗科的临床应用情况。方法：详细描述制作Corvus IMRT治疗计划、质量控制和质量监测的整个过程；利用该IMRT，联合外照射和X-刀根治性治疗T4NOMO鼻咽癌1例，及单纯IMRT治疗胸椎体转移癌1例。结果：从靶区各个剖面可见高剂量等剂量曲线按计划设计紧扣靶区，重要器官和敏感组织受到保护，治疗计划统计表显示靶区、重要器官和敏感组织的最高及最低受量和受照射体积，而剂量体积直方图则直观地提示肿瘤组织和周围器官的受量比较。结论：IMRT靶区剂量分布均匀，正常组织及敏感器官受到最大限度的保护，可对某些病种的肿瘤组织施以高剂量放疗。

Clinical Practice of Intensity Modulated Radiation Therapy

Objective:The current study was designed to rev iew the clinical practice of intensity modulated radiation therapy(IMRT)in department of radiation oncology,Stanford university medical cente r.Methods:An inverse planning system(Corvus,NOMOS corporation)was used to optimize IMRT treatment plans for 2patients.IMRT using 9coplanar beams was a part of ra dical irradiation,combined with external beam therapy.An X-knife radi osurgery boost was added to the first case with nasopharyngeal carcinoma.IMRT was the single modality in the treatment of thoracic vertebral metastases in th e second patient.Results:The optimized isodose distribution s in various plans showed the best compromise between the targ et volume dose requirements and the d ose constraints placed upon the sensitive structures.The statistics of the pl an summarized the volume,dose range in the targets and the organs or tissu es concerned.Dose volume histograms o ffered a direct comparison of dose-volume in tumor and sensitiv e structures.Conclusions:IMRT can yield a sufficiently homoge neous desired dose distribution which results in a high degree of sparing of sensitive structures.It can be impl emented to escalate target doses in some cases.