由于肺癌早期诊断困难,常使病人病变广泛时方来就诊。据等的材料,在住院病人中仅有49%是ⅠⅡ期患者,所以很大部分肺癌的手术处理是探查性的。临床上,术前病人检查的主要目的之一是发现肿瘤侵犯或转移到纵隔部位,因为这是开胸探查最常见的适应症。为此目的所应用的X 线检查,常不可靠。首先因为肺的所有各组淋巴结并非均能用X 线检查到。其次,淋巴结肿大,不能肯定就是癌转移。据 Because of the difficulty in early diagnosis of lung cancer, it is often the case that patients have extensive disease. According to other materials, only 49% of hospitalized patients are stage III patients, so surgical treatment of a large part of lung cancer is exploratory. Clinically, one of the main purposes of preoperative patient examination is to find tumor invasion or metastasis to the mediastinum, as this is the most common indication for thoracotomy exploration. The X-ray examination applied for this purpose is often unreliable. First of all, because all the lymph nodes in the lungs cannot be detected by X-rays. Second, lymphadenopathy can not be sure of cancer metastasis. according to