野中野正向调强与固定野逆向调强在全脑放疗中的剂量学差异  

Dosimetry difference between field-in-field intensity modulated radiation therapy and fixed field inversely optimized intensity modulated radiation therapy in whole brain radiotherapy

作　　者：潘香[1] 李娅[1] 朱思瑾 杨毅[1] PAN Xiang;LI Ya;ZHU Sijin;YANG Yi(Department of Radiotherapy,Yunnan Provincial Tumor Hospital,The Third Affiliated Hospital of Kunming Medical University,Kunming,Yunnan,650118)

机构地区：[1]昆明医科大学第三附属医院云南省肿瘤医院放射治疗科

出　　处：《实用临床医药杂志》2019年第19期12-16,共5页Journal of Clinical Medicine in Practice

摘　　要：目的比较全脑放疗的野中野正向静态调强(FIF-IMRT)与固定野逆向优化调强(FFIO-IMRT)技术的剂量学差异。方法选取需行全脑放疗患者20例,采用Pinnacle39. 10治疗计划系统进行计划设计,2种计划均用6 MV X射线,处方剂量均为40 Gy,2 Gy/次,共20次。FIF-IMRT计划选270°、90°为主野,适当调整准直器角度,使双眼球重叠,在每个主野方向手动添加1~2个子野降低高剂量。FFIO-IMRT计划7野均分调强,通过反复改变优化参数来达到临床要求的剂量分布。比较2种放疗计划的剂量学参数。结果①靶区方面:与FFIO-IMRT计划相比,FIF-IMRT计划的计划靶区(PTV)的V105%、D50%升高,Dmin、Dmax、V95%、V110%、D2%、D98%降低,差异均有统计学意义(P <0. 05);FIF-IMRT计划的CI低于FFIO-IMRT,HI却高于FFIO-IMRT,差异均有统计学意义(P <0. 05);FIF-IMRT计划子野数、机器跳数MU、治疗时间、计划设计时间均较FFIO-IMRT显著降低(P <0. 05)。②危及器官左右晶体、左右眼球、脊髓、左右视神经方面,FIF-IMRT计划低于FFIO-IMRT计划,晶体尤为明显,除左右视神经外,其他差异均有统计学意义(P <0. 05)。结论①2种计划的靶区均达到临床剂量学要求。②FIF-IMRT计划在靶区的适形性上虽差于FFIO-IMRT计划,但在危及器官的保护方面远好于FFIO-IMRT计划。③由于FIF-IMRT计划的单次治疗时间显著减少,因此降低了器官运动带来的误差,同时减少了机器的损耗,提高了机器执行效率。④FIF-IMRT计划设计简单易行,在基层医院也较容易实现。故全脑放疗推荐野中野正向静态调强的方式。Objective To compare dosimetry difference between field-in-field intensity modulated radiation therapy(FIF-IMRT) and fixed field inversely optimized intensity modulated radiation therapy(FFIO-IMRT) in whole brain radiotherapy. Methods Totally 20 patients with whole brain radiotherapy were selected. The Pinnacle39. 10 treatment planning system was used to design plan. 6 MV X-ray was used for both two plans,and the prescription dosage was 40 Gy,with 2 Gy per time for20 times totally. FIF-IMRT plans to select 270 and 90 degrees as the main fields,adjust the collimator angle appropriately to make the eyes overlap,and manually add 1 or 2 sub-fields in each main field direction to reduce the high dose. FFIO-IMRT plans to equalize the intensity of 7 fields and achieve the clinical dose distribution by repeatedly changing the optimized parameters. The dosimetric parameters of two radiotherapy schemes were compared. Results Compared with FFIO-IMRT,the V105%and D50%of the planned target area(PTV) in FIF-IMRT increased significantly,while Dmin,Dmax,V95%,V110%,D2%,D98%decreased significantly(P < 0. 05). CI of FIF-IMRT was significantly lower than that of FFIO-IMRT,but HIV was significantly higher than that of FFIO-IMRT(P < 0. 05).The number of planned subfields,machine hops MU,treatment time and planning design time of FIF-IMRT were significantly lower than those of FFIO-IMRT(P < 0. 05). The FIF-IMRT plan was significantly lower than the FFIO-IMRT plan in terms of organ-threatening left and right crystals,right and left eyeballs,spinal cord and right optic nerves,especially in crystals. There were significant differences except for left and right optic nerves between two plans(P < 0. 05). Conclusions① Both treatment plans could meet the requirements of clinical dosimetry. ② Although the CI of FIF-IMRT is worse than FFIO-IMRT,but FIF-IMRT is better in protection of organs. ③ Since the single treatment time of FIF-IMRT significantly shorten,the errors caused by organ movement are reduced,the loss of MLC is reduced,and th

关 键 词：全脑放疗 野中野正向调强放射治疗 固定野逆向调强放射治疗 剂量学 

分 类 号：R815[医药卫生—放射医学]