双层探测器光谱CT在中央型肺癌合并肺不张精准放疗中的应用价值

Application value of dual-layer spectral detector CT in precise radiotherapy for central lung cancer with atelectasis

目的探讨双层探测器光谱CT(DLSDCT)在中央型肺癌(CLC)合并肺不张精准放疗中的价值。方法回顾性分析2020年4月至2021年11月山东第一医科大学第三附属医院及山东省肿瘤医院经病理证实的26例CLC合并肺不张患者的临床及影像资料(DLSDCT、PET-CT及放疗模拟定位CT图像)。26例患者中男21例,女5例,年龄36~82岁。2名医师分别在DLSDCT、PET-CT及模拟定位CT图像上评估CLC可识别率,并勾画大体肿瘤体积(GTV),测量GTV值(GTVDLSDCT、GTVPET-CT、GTVCT)。采用配对样本Friedman检验比较3种图像GTV的差异,两两比较采用SNK检验并经Bonferroni校正。采用组内相关系数(ICC)比较2名医师间测量GTV值的一致性。结果PET-CT、DLSDCT、放疗模拟定位CT图像上CLC可识别率分别为100%(26/26)、80.77%(21/26)、11.54%(3/26),DLSDCT图像上CLC可识别率显著高于模拟定位增强CT(χ^(2)=16.06,P<0.001)。模拟定位CT图像、PET-CT图像、DLSDCT图像上测量的GTVCT、GTVPET-CT、GTVDLSDCT分别为58.75(22.57,86.17)cm^(3)、47.34(18.13,69.25)cm^(3)、51.40(18.87,71.31)cm^(3),差异有统计学意义(χ^(2)=44.99,P<0.001),其中GTVDLSDCT和GTVPET-CT均明显小于GTVCT(χ^(2)=4.23、6.59,Bonferroni法校正P<0.001),GTVDLSDCT和GTVPET-CT差异无统计学意义(χ^(2)=2.36,Bonferroni法校正P=0.055)。在DLSDCT和PET-CT上测量的GTV值2名医师间一致性均较好(ICC=0.86、0.89)。结论在DLSDCT图像上,多数CLC和肺不张可被识别。与模拟定位CT相比,DLSDCT上勾画的肿瘤靶区更接近于PET-CT,不同医师勾画的肿瘤体积一致性更高。

Objective To evaluate the value of dual-layer spectral detector CT(DLSDCT)in precise radiotherapy for central lung cancer(CLC)complicated with atelectasis.Methods Clinical and imaging data(including DLSDCT,PET-CT,and radiotherapy simulation CT images)of 26 patients with pathologically confirmed CLC accompanied by atelectasis from the Third Affiliated Hospital of Shandong First Medical University and Shandong Cancer Hospital were analyzed retrospectively.There were 21 males and 5 females,aged 36-82 years.Two physicians assessed CLC identifiability on DLSDCT,PET-CT,and simulation localization CT images,respectively,and outlined the gross tumor volume(GTV)and measured GTV values(GTVDLSDCT,GTVPET-CT,GTVCT).Paired-sample Friedman test was used to compare the differences in GTV of the three images,and the SNK test with Bonferroni correction was used for a two-way comparison.The intra-class correlation coefficient(ICC)was used to compare the agreement of measured GTV between 2 physicians.Results The differentiation rates on PET-CT,DLSDCT,and simulation CT images were 100%(26/26),80.77%(21/26),and 11.54%(3/26),respectively.The differentiation rate of CLC on DLSDCT images was significantly higher than that on simulation CT images(χ^(2)=16.06,P<0.001).GTVCT,GTVPET-CT,and GTVDLSDCT measured on simulation localization CT images,PET-CT images,and DLSDCT images were 58.75(22.57,86.17)cm^(3),47.34(18.13,69.25)cm^(3),and 51.40(18.87,71.31)cm^(3),respectively,with statistically significant differences(χ^(2)=44.99,P<0.001).Both GTVDLSDCT and GTVPET-CT were significantly smaller than GTVCT(χ^(2)=4.23,6.59,Bonferroni corrected P<0.001),and there was no significant difference between GTVDLSDCT and GTVPET-CT(χ^(2)=2.36,Bonferroni corrected P=0.055).The agreement between the two physicians was good for GTV values measured on both DLSDCT and PET-CT(ICC=0.86,0.89).Conclusions On DLSDCT images,most CLC and atelectasis can be identified.Compared to simulation localization CT,the tumor target areas outlined on DLSDCT are closer to PET-CT,and the tumor volumes outlined by different physicians are more consistent.