【摘要】 目的比较分析鼻咽癌固定射野调强(IMRT)和容积旋转调强(VMAT)计划的靶区和危及器官(OAR)的剂量差异及分次治疗时间和机器跳数的差异。方法选择在我院接受放疗的15例鼻咽癌患者,对其进行IMRT和VMAT计划设计的比较。结果靶区:VMAT的大部分参数的HI和CI及D1%和Dmeans优于IMRT计划的结果。OAR:虽然脑干的Dmeans、左右视神经的D1%及右晶体的D1%的差异无统计学意义,但其余指标差异均有统计学意义,且VMAT的结果优于IMRT。分次治疗时间:VMAT(4.1 min)要少于IMRT(8.8 min)。分次治疗跳数:VMAT(597.7 MUs)要比IMRT(823.5 MUs)少约37.8%。结论鼻咽癌的IMRT和VMAT计划在靶区剂量和OAR保护上都可以达到临床要求,但VMAT的大部分指标要优于IMRT。不过,VMAT在对视神经及晶体等小体积OAR的保护上没有太大优势。VMAT的分次治疗时间和机器跳数都要小于IMRT。更多还原

【Abstract】 Objective To compare IMRT with VMAT for NPC patients with regard to the sparing effect on organ at risk( OAR),dosimetric quality,treatment delivery time and monitor units( MUs). Methods Fifteen patients with NPC were planned by IMRT and VMAT for dosimetric comparison. Results For most parameters such as HI CI Dmeansand D1%in target area,the results of VMAT plans were better than those of IMRT plans. In OAR,although for Dmeansof brain stem and D1%of optic nerves and right lense,there were no significant difference between VMAT and IMRT,VMAT plans had a better sparing effect for most parameters. The delivery time per fraction for VMAT( 4. 1 min) was much shorter than the time for IMRT( 8. 8min). Compared to IMRT( 823. 5 MUs),VMAT( 597. 7 MUs) reduced Mus by 37. 8%. Conclusion The results indicate that IMRT plan and both VMAT plan could have similar target coverage and meet clinical needs,however for most parameters in target area and OAR,the results of VMAT plans were better than these of IMRT plans,particularly on HI and CI of target and to protect OAR such as brain- stem spine- cord and parotid,but VMAT plans were as if not enough to protect small volume OAR such as optic nerve,optic chiasma and lense. VMAT provided shorter delivery time per fraction and fewer monitor units than IMRT.更多还原