千伏级X线透视成像与锥形束CT确定头颈部摆位误差的比较  

Comparing the performance of two methods to determine set-up errors for patients with head-and- neck cancer

作　　者：李明辉[1] 张寅[1] 戴建荣[1] 张彦新[1] 高黎[1] 

机构地区：[1]中国医学科学院北京协和医学院肿瘤医院肿瘤研究所放疗科,北京100021

出　　处：《中华放射肿瘤学杂志》2012年第4期374-376,共3页Chinese Journal of Radiation Oncology

摘　　要：目的比较千伏级x线正交透视成像与锥形束CT（CBCT）成像方法在确定头颈部肿瘤患者摆位误差的一致性，为临床选择成像方法提供参考。方法将16例头颈部肿瘤患者共计160套正交透视图像与数字重建透视图像配准，160套CBCT图像与定位CT图像配准，得出患者左右（＊）、上下（y）、前后（z）方向平移摆位误差。使用Pearson相关分析法检验相关性，Bland-Altman绘图法检验两种方法的一致性。结果x、y、z方向尺。值分别为0．768、0．832、0．727，P值均〈0．01，且两种方法的测量结果呈正相关。x、y、z方向95％一致性限度分别为[1．33mm，-1．21mm]、[1．58mm，-1．08mm]、[0．79mm，-1．37mm]，均〈2mm界值，表明两种测量方法具有一致性。结论在确定头颈部肿瘤患者摆位误差时，千伏级X线透视与锥形束CT是一致的；考虑到CBCT成像剂量比透视成像剂量高一个数量级，且可提供更多解剖信息，建议将两种方法结合应用。Objective Both kilovolt （KV） cone-beam computed tomography （CBCT） and KV radiography can determine set-up errors for patients with head-and-neck cancer. This study is to compare their performance. Methods 16 patients with head and neck cancer were enrolled in this study. There were 160 sets of CBCT and corresponding orthogonal radiography images. Through registration of CBCT images with the planning CT images, and registration of radiography images with the digitally reconstructed radiographs, translational set-up errors were determined along left-fight （x）, super-inferior （y）, and anterior-posterior （z） directions. Pearson correlation analysis was performed to evaluate the correlation of the set up errors determined by the two methods, and Bland-Altman plot analysis was used to assess the coincidence of these two methods. Results The Pearson coefficient of correlation along all three directions was less than 0. 01, and R2 was 0. 95,0. 84, 0. 81 on x, y, z, respectively. That means high correlation for two methods. The Bland-Airman plot analysis showed that the 95% agreement limits of agreement were within preset 2 mm tolerance （x[ 1.3 mm, - 1.2 mm] ,y[ 1.6 mm, - 1.1 mm] ,z[0. 8 mm,-1.4 mm] ）, which indicates an agreement exists for two methods. Conclusions For determination of set-up errors for patients with head and neck cancer, KV radiography is equivalent to CBCT. Considering CBCT delivers higher dose than KV radiography, but provides more soft tissue information. We suggest to use these two methods combinative in clinic.

关 键 词：体层摄影术 X线计算机 千伏级锥形束 正交透视成像 千伏级x线 图像配准 

分 类 号：R739.91[医药卫生—肿瘤] TP391.41[医药卫生—临床医学]