螺旋CT低剂量扫描筛查早期肺癌的研究

Screening early-stage pulmonary cancer using low-dose CT scanning

肺癌是目前世界上常见的恶性肿瘤之一。肺癌的早期发现、早期诊断和早期治疗是降低肺癌病死率 ,提高肺癌长期生存率的惟一途径。胸部X线片检查由于经济、射线量小、无创 ,与痰细胞学检查一起成为筛查肺癌的首选检查手段 ,但发现小肿瘤的敏感性较差。CT筛查肺癌可能促进早期肺癌发现、降低肺癌病死率 ,但CT常规剂量扫描由于放射剂量大 ,每次接受检查不符合体检筛查要求。由于空气与肺病变有较高对比 ,故降低放射剂量仍可能获得良好的胸部CT图像。低剂量CT接受的放射剂量仅是传统CT剂量的 1/6。LDCT的筛查阳性结果是胸部X线片筛查的 3倍 ;LDCT筛查发现恶性病变是胸部X线片筛查的 4倍 ,LDCT筛查发现的Ⅰ期肺癌是胸部X线片的 6倍。LDCT筛查肺癌存在的争议 :①LDCT筛查肺癌能否降低肺癌病死率 ;②LDCT筛查肺癌的假阳性率高及过诊问题 ;③LDCT筛查肺癌的误漏诊问题。

Lung cancer is one of the most common malignant tumors in the world.The early detection,early diagnosis and early treatment is the only method to decrease the mortality of lung cancer patients and increase the long term survival rate of the patients as well.The chest X-ray exam,because of its low expense,low radiation dose,noninvasive method,has become the primary exam method together with sputum cytological examination.However,it's sensitivity is not so good.Screening with chest CT could aid to detect lung cancer early and decrease the mortality rate of patients,whereas it is not suitable for screening because the common CT scan uses a large dose of radiation.Because the air and the pathologic focus have high contrast under X-ray scan,it is possible to get good CT graphics in the lung.Low-dose CT uses only 1/6 dose of radiation of traditional CT.The positive results of LDCT screening are 3 times of chest X-ray exam.The positive results of LDCT screening of detecting malignant tumors are times of chest X-ray exam.The detection of stage-I lung cancer is 6 times of chest X-ray exam.The debates of LDCT screening include:①whether LDCT could decrease the mortality rate of lung cancer patients? ②Whether LDCT has a high false positive rate and over-diagnosis in screening of lung cancer?③Whether LDCT has false diagnosis or misdiagnosis?