PET-CT在局部晚期非小细胞肺癌调强放疗靶区勾画中的应用

Application of PET-CT fusion image to delineate targets of IMRT in patients with locally advanced NSCLC

目的探讨基于适形调强放疗(IMRT)和PET/CT指导的个体化放疗对局部晚期非小细胞肺癌(NSCLC)肺组织受照剂量的影响,并探索PET-CT参数与NSCLC放射敏感性的关系。方法选取2016年9月至2017年5月郑州大学附属肿瘤医院收治并前瞻性入组的15例局部晚期(ⅢA和ⅢB期)非小细胞肺癌初治患者,按1∶1随机分为标准放疗组和个体化放疗组。依据单纯增强CT图像和同一固定体位下PET-CT与CT融合图像勾画靶区和危及器官,比较两组初次放疗计划(PTV处方剂量40Gy/30f)中双肺受照体积V5、V10、V15、V20、V30及肺平均剂量(MLD)、平均心脏受照射剂量(MHD)、脊髓平均剂量;在处方剂量达40Gy时,对患者进行第2次PET-CT显像,测量SUVmax,ΔSUVmax,ΔSUVmax%,分析两组患者参数间的差异。结果与标准化治疗组比较,应用PET-CT融合靶区的个体化治疗组的双肺V15、V20、V30减小明显(P<0.05),V5、V10、MLD、MHD、脊髓Dmean、ΔSUVmax、ΔSUVmax%之间差异均无统计学意义(P>0.05)。结论应用PET-CT融合图像勾画靶区能提高靶区勾画的精确性,降低正常肺组织的照射剂量。

Objective To investigate the effect of individualized radiotherapy based on intensity modulated radiation therapy（IMRT） and PET/CT on the dose of lung tissue in patients with locally advanced non-small cell lung cancer（NSCLC）,and to explore the relationship between PET-CT parameters and radiosensitivity. Methods Totally 15 NSCLC patients with locally advanced stage（stage ⅢA and ⅢB） were 1∶1 randomly divided into standard radiotherapy group and individual radiotherapy group. According to the simple enhanced CT images and the same fixed position PET-CT and CT fusion images delineate the target volume and organ at risk. Compared lung V5,V10,V15,V20,V30,MLD,MHD,spinal cord between two groups of the first radiotherapy treatment planning; Each patients received second PET-CT at midtreatment time when a therapy prescription dose of 40 Gy was delivered. We assessed SUVmax,ΔSUVmax,ΔSUVmax%,analyze the differences between the two groups of parameters. Results Compared with the standardized treatment group,The difference in lung V10,V20,V30 were statistically significant（P〈0. 05）,while the differences in mean lung dose,mean heart dose,spinal cord Dmean,lung V5,V10,ΔSUVmax and ΔSUVmax% were not significant（P〉0. 05）. Conclusion Application of PET-CT/CT fusion image to delineate the targets of IMRT can improve the accuracy of target delineation volume and reduce the dose of normal lung tissus.