CAJ | 학술논문

目的比较不同全脑全脊髓放射治疗(CSI)方式的剂量学差异及摆位误差对靶区剂量的影响.方法选取2011年7月至2012年10月间接受CSI的9例患者的CT图像,分别完成常规二维(2D)、单野三维(3D-1)、三野三维(3D-3)、逆向调强(IMRT)及电子线的CSI计划,比较不同计划间靶区的覆盖度(V95)、高量(V107)、最大剂量(Dmax)、适形指数(CI)、剂量均一性指数(HI);观察甲状腺、心脏、双肺、小肠、肾脏及全身正常组织5、15、25 Gy的受照体积.取患者每周的3个治疗中心(头部、上段脊髓、下段脊髓)的摆位误差值,将该周5次放疗计划的治疗中心分别按照此值移动得到新的放疗计划,比较不同计划方式新计划的靶区剂量与原计划的差异.结果电子线V95略低于其余各组(q=11.2～11.7,P＜0.05).IMRT具有最小的V107(q =4.3 ～11.6,P＜0.05),其次为3D-3(q =4.3 ～7.1,P＜0.05);2D具有最大的Dmax(q=2.4～2.7,P＜0.05);各组HI的差异无统计学意义;靶区CI从高至低依次为,IMRT＞ 3D-3＞2D、3D-1及电子线(q=7.1 ～14.3、7.1 ～9.6、0.00～0.01,P＜0.05).IMRT及电子线可以显著降低各器官及全身组织接受的15 Gy及25 Gy剂量;3D-3次之.但与2D及3D-1相比,3D-3及IMRT均不同程度增加了5 Gy的照射体积.引入摆位误差后,3D-1及3D-3靶区剂量与原计划差别小于其余各组(q=2.8～4.1,P＜0.05).结论对于脊髓深度＜4.5 cm者,电子线有可能是一种安全、可靠的治疗方式.3D-1虽适形度略差,但有减少摆位误差的影响、降低低剂量体积的趋势,仍为可考虑治疗方式之一.3D-3及IMRT显示了较好的靶区剂量分布,但其大范围低剂量体积需引起重视.
목적 비교불동전뇌전척수방사치료(CSI)방식적제량학차이급파위오차대파구제량적영향.방법 선취2011년7월지2012년10월간접수CSI적9례환자적CT도상,분별완성상규이유(2D)、단야삼유(3D-1)、삼야삼유(3D-3)、역향조강(IMRT)급전자선적CSI계화,비교불동계화간파구적복개도(V95)、고량(V107)、최대제량(Dmax)、괄형지수(CI)、제량균일성지수(HI);관찰갑상선、심장、쌍폐、소장、신장급전신정상조직5、15、25 Gy적수조체적.취환자매주적3개치료중심(두부、상단척수、하단척수)적파위오차치,장해주5차방료계화적치료중심분별안조차치이동득도신적방료계화,비교불동계화방식신계화적파구제량여원계화적차이.결과 전자선V95략저우기여각조(q=11.2～11.7,P＜0.05).IMRT구유최소적V107(q =4.3 ～11.6,P＜0.05),기차위3D-3(q =4.3 ～7.1,P＜0.05);2D구유최대적Dmax(q=2.4～2.7,P＜0.05);각조HI적차이무통계학의의;파구CI종고지저의차위,IMRT＞ 3D-3＞2D、3D-1급전자선(q=7.1 ～14.3、7.1 ～9.6、0.00～0.01,P＜0.05).IMRT급전자선가이현저강저각기관급전신조직접수적15 Gy급25 Gy제량;3D-3차지.단여2D급3D-1상비,3D-3급IMRT균불동정도증가료5 Gy적조사체적.인입파위오차후,3D-1급3D-3파구제량여원계화차별소우기여각조(q=2.8～4.1,P＜0.05).결론 대우척수심도＜4.5 cm자,전자선유가능시일충안전、가고적치료방식.3D-1수괄형도략차,단유감소파위오차적영향、강저저제량체적적추세,잉위가고필치료방식지일.3D-3급IMRT현시료교호적파구제량분포,단기대범위저제량체적수인기중시.
Objective To make a dosimetric comparison of different craniospinal irradiation (CSI) plans and to explore the impacts of setup error on target dose distribution.Methods Five radiotherapy plans [2D-conventional,single filed 3D(3D-1),three fields 3D(3D-3),IM RT and electron]were made from 9 patients' CT images,who received CSI from July 2011 to October 2012.The target coverage (V95),hot spot (V107),maximum dose (Dmax),conformal index (CI) and dose homogeneity index (HI) of the target of each plan were compared.The volume of thyroid,heart,lungs,small intestine,kidney and normal tissue irradiated by 5,15,25 Gy were observed.The setup errors of the three treatment centers(head,upper spinal,lower spinal) per week were recorded and the treatment centers of the five plan in the week were moved according to the collected data to make a new plan,then the comparison of the target doses with the original plans were performed.Results The V95 of electron was lower than the other groups (q=11.2-11.7,P＜0.05),the difference between the rest of the group was not statistically significant (q=0.00-0.01,P ＞ 0.05).IMRT had the smallest V107 (q =4.3-11.6,P ＜0.05),followed by the 3D-3 (q=4.3-7.1,P＜0.05),2D had the largest Dmax(q =2.4-2.7,P ＜0.05).The differences from HI in each group was not statistically significant.CIs from high to low were IMRT＞ 3D-3＞ 2D,3D-1 and electron (q=7.1-14.3,7.1-9.6,0.00-0.01,P＜0.05).IMRT and electron could significantly reduce the volume irradiated by 15 Gy and 25 Gy and 3D-3 was the second.However,compared with 2D and 3D-1,there were 5 Gy irradiation volume increased in 3D-3 and IMRT.When setup errors were taken into account,there was the smallest difference between the dose distribution of3D-1,3D-3 and the original plan(q=2.8-4.1,P＜0.05).Conclusions For those spinal cord depth ＜4.5 cm,electron could be regarded as a kind of safe and reliable way of CSI.Although the CI of 3D-1 is slightly less,it still could be used as the choice of CSI with the trend of less being affected by setup errors and reducing low dose volume.While the 3D-3 and IMRT have better target dose distribution,the large volume of low dose region is a thought-provoking problem.