摘要
目的探讨Eclipse上的优化工具NTO(normal tissue objective)对直肠癌术后调强放疗的剂量影响。方法随机选取20例直肠癌术后患者,每位患者均制定3组调强计划。对照组为手动NTO,其他2组分别为自动NTO和无NTO,在相同的优化条件下,自动NTO和无NTO与对照组比较靶区和危及器官剂量学参数以及机器跳数。结果与对照组相比,自动NTO计划组适形度指数(CI)更差(t=3.248,P<0.05),正常组织D^(mean)高0.6%(t=−3.678,P<0.05),危及器官受量和机器跳数差异均无统计学意义(P>0.05);无NTO计划组CI较差(t=16.716,P<0.05),均匀性指数较好(t=6.594,P<0.05),正常组织D^(mean)高3.19%(t=−8.560,P<0.05),除小肠D^(max)更高外其他危及器官受量差异均无统计学意义(P>0.05),机器跳数增加3.95%。结论从靶区和危及器官的剂量学结果看,手动NTO和自动NTO、无NTO均能满足临床需求,但无NTO会增加靶区外热点、机器跳数和正常组织D^(mean),手动NTO优势不明显,建议自动NTO用于直肠癌固定野调强放疗。
Objective To analyze the dosimetric effect of the optimization tool,normal tissue objective(NTO),in Eclipse on the intensity modulated radiation therapy(IMRT)for postoperative patients with rectal cancer.Methods Twenty postoperative patients with rectal cancer were randomly selected.Based on the Eclipse treatment planning system,three IM-RT plans were formulated for each patient,with manual NTO as the control group,and automatic NTO and no NTO as the other two groups.The dosimetric parameters of the target volume and organs at risk(OAR)and the monitor units(MU)were compared between the automatic NTO and no NTO groups and the control group under the same optimization conditions.Results Compared with the control group,the automatic NTO group showed a worse conformity index(CI)(t=3.248,P<0.05),a 0.6%higher D^(mean)of normal tissues(t=-3.678,P<0.05),and no significant difference in the dose to OAR and the MU(P>0.05);the no NTO group showed a worse CI(t=16.716,P<0.05),a better homogeneity index(t=6.594,P<0.05),a 3.19%higher D^(mean)of normal tissues(t=-8.560,P<0.05),no significant difference in the dose to OAR except the small intestine with higher D^(max)(P>0.05),and a 3.95%increase in the MU.Conclusion From the dosimetry results of the target volume and OAR,the plans with manual NTO and automatic NTO,and without NTO can meet clinical needs,but the plan without NTO increases the hot spots outside the target volume and the MU as well as the D^(mean)of normal tissues.Manual NTO has no obvious advantages over automatic NTO which is recommended for the fixed-field IMRT of rectal cancer.
作者
吴哲
刘可
明智
王东
曹俊逸
WU Zhe;LIU Ke;MING Zhi;WANG Dong;CAO Junyi(Department of Oncology,Zigong First People's Hospital,Zigong 643000 China)
出处
《中国辐射卫生》
2022年第4期471-476,共6页
Chinese Journal of Radiological Health
关键词
直肠癌
固定野调强
NTO
剂量学
ECLIPSE
Rectal cancer
Fixed-field intensity modulated radiation therapy
Normal tissue objective
Dosimetry
Eclipse
