肺癌篩檢使用低劑量多探頭電腦斷層掃描與一般胸部X光之比較

A Comparison of Lung Cancer Screening Methods Using Low-Dose Multidetector Computed Tomography and Conventional Chest Radiography

根據行政院衛生署公布台灣癌症登記報告，肺癌高居第二位，肺癌死亡率高居女性第一位。在美國，肺癌五年的存活率13％，十年的存活率7％。肺癌屬於早期診斷才能獲得較佳的預後。不幸地，在美國只有15％的肺癌是早期被診斷出來，因此若能找到更有效的肺癌篩選（lung cancer screening）方法，理論上是可以延長存活時間。材料與方法：使用多探頭螺旋式電腦斷層掃描儀（multi－detector helical computed tomography）與X光機用來篩選腩癌。根據Henschke,McCauley and Yankelevitz（1999）的研究，將1000位肺癌高危險群，年齡超過六十歲，抽煙超過十年，無症狀或先前有癌症的志願者，使用低劑量電腦斷層掃描（low-radiation-dose computed tomography）和胸部X光（chest radiography）來檢查，比較兩者的差異。結果：低劑量電腦斷層掃描的檢查費用約新台幣5000元，胸部X光的檢查費用約新台幣200元－300元；根據研究報告，低劑量電腦斷層掃描儀的輻射劑量約為0.4毫西弗－0.5毫西弗，胸部X光的輻射劑量約為0.125毫西弗－0.25毫西弗；低劑量電腦斷層掃描儀對於非鈣化結節的偵測率為23％，胸部X光對非鈣化結節的偵測率為7％。結論：低劑量電腦斷層掃描儀對於肺癌的篩選率雖然優於胸部X光，但所偵測出肺癌第一期的比例只有10％，還不夠高，因此對於提昇肺癌病患的存活率，沒有顯著的幫助。

According to the recent report by the Department of Health, Executive Yuan, ROC, lung cancer was the second leading cause of cancer deaths, and the first leading cause of cancer deaths for women. In United States, the 5-year survival rate of lung cancer is respectively 13%, and 7% for 10-year survival rate. It can have better results of prognosis whenever diagnosis was made earlier. Therefore, if one can find an effective way for lung cancer screening, the survival rate can be lengthened. Methods and materials: according to the report of Henschke et al.,1999, total number of one thousand volunteers with high risk of lung cancer, (age＞60, smoking years ＞10 years) were investigated by using both Low-radiation Dose Computed Tomography (LDCT) and Chest Radiography, the result were then compared with each other. Results: the sensitivity for the uncalcified nodule detected by the LDCT was 23%, and 7% by the chest radiography. The radiation dose of the LDCT was 0.4-0.5mSv, and 0.125-0.25mSv for chest radiography, the proportion of the first stage was only 10% not good enough. Therefore there was no significant improvement for the survival rate of the lung cancer patients.