放射治疗计划中勾画靶区的主观差异性研究

目的 了解大体肿瘤靶区（GTV）勾画在不同年资、学科医师及不同时间方面的差异性,并分析其原因.方法 针对鼻咽癌和肺癌患者的CT定位图像,安排12位医师进行了GTV勾画,其中放射治疗科医师9位（包括住院医师、主治医师、主任医师各3位）,影像诊断科医师（年资在十年以上）3位.计算患者GTV体积值、层面、冠状面X轴最大值及其变化范围,比较两个学科医生和不同年资医生在先后三次勾画中所产生的差异性.结果 影像诊断医生勾画肿瘤GTV体积较肿瘤放疗科医生小.肿瘤放疗科医生年资越高,勾画GTV体积越小.除一例肺癌合并肺不张患者外,各组医生勾画肺癌的GTV的层面和冠状面X轴最大值之间差异无统计学意义.各组医师先后三次勾画GTV体积、层面及冠状面X轴最大值之间差异无统计学意义.结论 肿瘤放疗科医生与影像诊断科医生勾画靶区存在明显差异.肿瘤放疗科各年资医生间在勾画靶区方面也存在差异.不同年资医生对肿瘤GTV勾画存在的差别应引起足够重视,应加强放射治疗科医生影像诊断水平,采用更先进的影像学检查手段,尽量多名医生共同参与来提高靶区勾画的准确性.

The Analyse of Subjective Differences in Contouring GTV of Radiotherapy Planning

Objective To realize the impact of subjective difference of vary years and subject physician in vary time interobservers in contouring of Gross Tumor Volumes（GTV） on the total accuracy in radiotherapy. Methods CT images from patients with nasopharyngeal neoplasm and lung neoplasm were reviewed by twelve physicians,nine from department of radiotherapy including residents,attending physicians and chief physicians, and three with more than ten years experience from department of radio-diagnosis.The variability of the value, lays and the maximum of coronal sections of GTV were calculated. Comparing its difference in successively three contouring from inter-specialty and inter-interval. Results The variability in the contouring of GTV between radiotherapists and radio-diagnosticians was statistically significant.The radio-diagnosticians were found more accurate in GTV delineation than radiotherapists,and the senior radiotherapists more accurate than junior radiotherapists. Except one case of lung neoplasm combined with atelectasis,the variability in GTV delineations of layers and the maximum of coronal sections were not statistically significant.The same group of physicians was found no significant variability in three times of GTV delineations of values,layers and the maximum of coronal sections.Conclusions A significant interobserver variability in GTV delineation between radio-therapists and radio-diagnosticians was demonstrated,and among radiotherapists of residents,attending doctors and chief physicians,there also have some differeiace.We have to pay more attention on variability in GTV delineation of different years and subject.To reduce this variation,we should intensify radiologic training,employed advanced image examination approaches and organize many physicians together to take part in radiotherapy planning.