目的 探讨螺旋断层放射治疗系统(TOMO)在计划中不同射野宽度对鼻咽癌(NPC)靶区和危及器官剂量学的影响.方法 选取2022年8月至2023年3月本院NPC患者15例,对其进行TOMO计划设计,分别完成不同射野宽度的计划设计,评价PGTVnx,PTVnd的均匀性指数(HI)、适形性指数(CI)、98%靶区体积剂量(D98)、2%靶区体积剂量(D2);PTV1、PTV2的CI;危及器官中脑干、视路系统(晶体、视交叉、视神经)、脊髓等最大剂量(Dmax)、腮腺、颌下腺、甲状腺、喉、口腔等平均剂量(Dmean);治疗时间、机器跳数(MU).结果 射野宽度为1 cm、2.5 cm、5 cm PGTVnx的HI为0.040±0.007、0.052±0.006、0.086±0.007;PTVnd的HI为0.026±0.001、0.039±0.003、0.058±0.003;射野宽度对靶区的HI影响明显,差异有统计学意义(P<0.05);射野宽度为1 cm、2.5 cm、5 cm PGTVnx的D2分别为72.100(71.800,72.200),73.200(72.350,73.391),74.829(74.800,75.300),射野宽度对靶区受照剂量影响明显,差异有统计学意义(P<0.05).不同射野宽度对左晶体Dmax(Gy)、右晶体Dmean(Gy)、左眼球Dmean(Gy)、右眼球Dmean(Gy)、左视神经Dmax(Gy)、右视神经Dmax(Gy)、视交叉Dmax(Gy)、脑干Dmax、左颞叶V60(cc)、右颞叶V60(cc)、右颞叶V65(cc)、口腔Dmean(Gy)、口腔V40(%)、左腮腺V30(%)、右腮腺V30(%)的差异均有统计学意义(P<0.05);不同射野宽度对机器跳数与治疗时间差异有统计学意义(P<0.05).结论 在NPC螺旋断层放射治疗中,保证体位准确的前提下,选取射野宽度为1.0 cm对视路系统,脑组织以及口腔腮腺等危及器官的剂量获益明显.
Objective To explore the dosimetric effects of different field widths(FW)on nasopharyngeal carcinoma(NPC)targets and dangerous organs in the planning and design of TOMO therapy Helical(TOMO).Methods Fifteen patients with NPC treated in our hospital from 2022.8 to 2023.3 were selected to design TOMO plans,and three groups of different field widths were designed under the condition that only the field width was changed,and the homogeneity index(HI),conformal index(CI),98%of the target volume dose D98%(D98)and 2%of the target volume dose of PGTVnx and PTVnd were evaluated.The Target volume dose(D2),CI of PTV1 and PTV2,maximum dose(Dmax)of brain stem,optic pathway system(lens,optic chiasm,optic nerve),spinal cord,etc were evaluated.In the organ at risk,average dose(Dmean)of parotid gland,submandibular gland,thyroid,larynx,oral cavity,treatment time,machine hop count(MU)were evaluated.Results The HI values for PGTVnx with field widths of 1cm,2.5 cm,and 5 cm were 0.040±0.007,0.052±0.006,and 0.086±0.007,respectively.The HI of PTVnd was 0.026±0.001,0.039±0.003,0.058±0.003.The width of the shooting field had a significant impact on the HI of the target area,and the difference was statistically significant(P<0.05).The D2 values of PGTVnx with field widths of 1 cm,2.5 cm,and 5 cm were 72.100(71.800,72.200),73.200(72.350,73.391),and 74.829(74.800,75.300),respectively.Field width had a significant impact on the radiation dose to the target area,and the difference was statistically significant(P<0.05).There were statistically significant differences in Dmax(Gy)of the left lens,Dmean(Gy)of the right lens,Dmean(Gy)of the left eyeball,Dmean(Gy)of the right eyeball,Dmax(Gy)of the left optic nerve,Dmax(Gy)of the right optic nerve,Dmax(Gy)of the optic chiasm,Dmax of the brainstem,V60(cc)of the left temporal lobe,V60(cc)of the right temporal lobe,V65(cc)of the right temporal lobe,Dmean(Gy)of the oral cavity,V40(%)of the oral cavity,V30(%)of the left parotid gland,and V30(%)of the right parotid gland with different field widths(P<0.05).There was a statistically significant difference(P<0.05)in the number of machines jumps and treatment time with different field widths.Conclusion In spiral sectional radiotherapy for nasopharyngeal carcinoma,while ensuring accurate positioning,selecting an irradiation field width of 1.0 cm yields significant dose benefits for critical organs such as the visual pathway system,brain tissue,and oral and parotid glands.
万方数据
维普
