Computed Tomography and Mediastinoscopy in the Assessment of Resectability of Lung Cancer

Abstract

In order to assess the potential of computed tomography (CT) of the mediastinum and mediastinoscopy in the staging of lung cancer, 125 patients were examined. Of these, 104 underwent thoracotomy, at which there was no evidence of mediastinal tumour involvement in 79 while 25 patients had signs of tumour spread. The sensitivity and specificity of CT were 87.0 per cent and 95.8 per cent, respectively, in the detection of direct tumour extension with a mediastinal mass. When lymph node enlargement was the sole finding, CT did not provide any differentiation between benign and malignant lymphadenopathy. The mediastinal involvement was inaccessible on mediastinoscopy in 18 cases (72%). Despite the surperior sensitivity of CT it was often difficult to determine whether direct tumour infiltratin of mediastinal structures had occurred. It was concluded that CT is necessary for screening the entire mediastinum and, when it reveals no evidence of mediastinal tumour spread, mediastinoscopy will yield no further information. Mediastinoscopy will help to correctly identify accessible mediastinal lymph node involvement of the superior mediastinum and to define the mediastinal tumour invasion in doubtful cases.

CT for Predicting the Resectability of Lung Cancer

“…Out of the 8 cases with undetectable N2 métastases, 6 were associated with a large central tumor, which probably masked the nearby satellites. On the other hand, benign reactive lymph node enlargement is a common finding in patients with lung cancer, and in our opinion it is usually impossible to distinguish reliably between benign and malignant enlarge ments (10,11). There was only one patient in this series who had large lymph nodes (3 cm) at several stations (2R, 4R, 4L, and 6 according to the ATS mapping) and thus fulfilled the criterion of having a definite stage Illb cancer.…”

“…This is a well-known disadvantage of tho racic C T (6,10,11,(18)(19)(20). In this series only o n e patient undergoing thoracotomy was estimated t o have a clear T 4 tumor with mediastinal infiltration, a n d this proved cor rect at exploration.…”