目的 通过非小细胞肺癌（NSCLC）图像引导放射治疗（IGRT）过程中，每次治疗前获取的锥形束CT图像，动态观察肿瘤体积的变化。 方法 2009年2月－2010年8月18例周围型NSCLC患者接受IGRT。每次治疗前进行千伏级锥形束CT（KV-CBCT）图像的采集。每周在KV-CBCT图像上勾画肿瘤靶区并计算靶区体积，经统计后分析肿瘤治疗过程中体积的变化。 结果 治疗开始时平均体积为28.5 cm3（2.5～109.1 cm3），治疗结束时平均体积为17.1 cm3 （1.4～73.4 cm3）。平均退缩率为35.9%（3.9%～68.9%），平均每天的退缩率为1.5% （0.1%～5.4%）。治疗结束时，0例病灶完全消退，1例部分消退，10例微小消退，7例稳定。 结论 治疗过程中，NSCLC肿瘤的退缩可以通过KV-CBCT进行观察。当病灶为周围型时，能对肿瘤体积的变化进行客观有效的评价。放射治疗过程中肿瘤的体积改变具有很大的异质性，肿瘤在治疗过程中体积均有一定的退缩，但治疗结束时大多数病灶仅为微小消退或稳定。
Objective To investigate the clinical features of non-small cell lung cancer (NSCLC) patients with long-term survival and the related factors for treatment. Methods A retrospective analysis of clinical features, treatment factors, and survival was performed for 963 patients with pathologically confirmed stage Ⅳ NSCLC between January 2010 and December 2015 from Department of Thoracic Oncology, West China Hospital, Sichuan University. Results The median overall survival (OS) of the 963 patients was 20.8 months, and the 1-, 3-, 5-, and 7-year survival rates were 72.0%, 21.4%, 15.2%, and 4.8%, respectively. There were 81 patients in the long-term survival group (OS>60 months) and 882 in the non-long-term survival group (OS<60 months). Previous surgery, thoracic radiotherapy and epidermal growth factor receptor (EGFR) gene positive significantly increased the 5-year actual survival rate, reducing the risk of death by 62.0%, 58.8%, and 58.1%, respectively. Compared with the non-long-term survival group, more patients in the long-term survival group received two or more means of treatment including surgery, thoracic radiotherapy, and targeted therapy (28.4% vs. 11.6%, P<0.001) and more patients benefited from fourth- or further-line treatment (24.7%vs. 11.1%, P<0.001). Cox multivariate regression analysis indicated that performance status [hazard ratio (HR)=1.388, 95% confidence interval (CI) (1.199, 1.608), P<0.001] , N stage [HR=1.160, 95%CI (1.058, 1.272), P=0.002] , EGFR gene status [HR=0.588, 95%CI (0.469, 0.738), P<0.001] , previous surgery [HR=0.626, 95%CI (0.471, 0.832), P=0.001] , and thoracic radiotherapy [HR=0.592, 95%CI (0.480, 0.730), P<0.001] were independent prognostic factors of OS. Conclusions Good performance status, early N staging, EGFR mutation, previous surgery, and thoracic radiotherapy are important prognostic factors affecting the survival of advanced NSCLC patients. Long-term survival benefits from combined treatment and effective further-line therapies.