摘要
[目的]由于多叶准直器的限制,鼻咽癌静态调强放疗时宽度大于14cm的射野一般分裂为2个或2个以上的分射野,本研究探讨减少分裂射野的可行性。[方法]选取10例已经治疗的初治且计划靶区宽度大于14cm的鼻咽癌病例进行研究,每病例做两组调强放射治疗计划,一组是传统分裂射野,另一组不分裂射野。对比两种方法对靶区的剂量覆盖、危及器官和正常组织照射剂量的差异,以及射野数、治疗时间和机器跳数的差异。[结果]不分裂射野组与传统分裂射野组的靶区剂量偏差小于0.3%,危及器官剂量偏差小于0.7%。剂量验证结果,两组参考点剂量通过率(100%,100%)和射野通量图剂量通过率(100%,99%)基本相同。不分裂射野组射野数减少33.1%±6.1%,机器出线跳数减少11.8%±4.6%,治疗时间减少14.5%±4.6%。[结论]不分裂射野方法较传统分裂野方法剂量分布相同,但可以有效减少射野数、机器跳数和治疗时间。
[Purpose] Due to the limitations of multi-leaf collimator, an intensity-modulated radiation therapy （IMRT） field width exceeding 14cm is split into two or more adjacent abutting sub-fields. This study aims to reduce the number of split-fields in static IMRT plan of nasopharyngeal carcinoma （NPC）. [Methods] Ten cases of NPC with PTV width exceeding 14cm were enrolled in the study. Two static IMRT plans with split field or nonsplit-field were generated for each patient. The dosimetric characters of two plans including target coverage, critical organ and normal tissue spare were compared. The total number of field, treatment time and monitor unit （MU） were also compared between two techniques. [Results] The dosimetric difference between two techniques was less than 0.3% for target volume. The organs at risk have dose-volume coverage difference less than 0.7% for two plans in all patients. The dosimetric verification result showed that the referent point absolute dose（100%,100%） and intensity map tests （100%,99%）all got through. Nonsplit-field technique produced statistically less sub-fields （33.1%±6.1%）, less MU （11.8%±4.6%） and less treatment time （14.5%±4.6%） than split-field technique. [Conclusion] Dosimetrically, nonsplit-field and split-field technique are similar for dose-volume coverage. However, the nonsplit-field method provides less sub-fields, lower MU, less treatment time.
出处
《中国肿瘤》
CAS
2010年第8期507-510,共4页
China Cancer
关键词
调强放射治疗
分射野
多叶准直器
鼻咽癌
intensity-modulated radiotherapy
sub-fields
multileaf collimator
nasopharyngeal carcinoma
