Mediastinal Staging of Non-Small-Cell Lung Cancer: Computed Tomography and Cervical Mediastinoscopy

Abstract

The exact indications for computed tomography (CT) of the thorax and mediastinoscopy (MS) in lung cancer still remain incompletely defined. The present study was designed to establish a standard approach to cervical MS for otolaryngologists, who in Denmark are traditionally involved in the staging of non-small-cell lung cancer (NSCLC). Sixty-four potentially operable patients with NSCLC underwent thoracic CT prior to bronchoscopy and cervical MS. Cervical MS alone established the histological diagnosis in 20% of the patients. In diagnosing lymph node metastases in the superior mediastinum, a criterion of 10 mm for abnormal enlargement resulted in an overall sensitivity and specificity of mediastinal CT of 81 and 84%, respectively, and the overall false-negative and false-positive rates appeared to be 10 and 29%, respectively. It could be demonstrated that mediastinal lymph nodes in patients with mediastinal metastases were significantly larger than mediastinal lymph nodes in patients without metastases. No clinicopathological characteristics could be identified to influence the accuracy of CT, except for the finding that the rate of false-negative mediastinal CT was significantly higher in patients with right-sided than in patients with left-sided lesions. It is concluded that because of the relatively low sensitivity and specificity of mediastinal CT, cervical MS remains essential in the evaluation of patients with presumed or verified NSCLC and that cervical MS, in experienced hands, is a safe and accurate procedure. For Danish otolaryngologists, the strategy of routine cervical MS, performed under general anaesthesia in the same stage as bronchoscopy, is advocated as a standard approach to mediastinal assessment for the staging of NSCLC. However, thoraco-abdominal CT is advocated for all patients with NSCLC, in whom operation is contemplated, as a supplementary investigation after other routine diagnostic and staging procedures, including cervical MS, have been carried out.

The size of mediastinal lymph nodes and its relation with metastatic involvement: a meta-analysis

“…Crossreferencing yielded another 23 potentially eligible studies. After full-text analysis, 14 were included [7][8][9][10][11][12][13][14][15][16][17][18][19][20], all of which had been identified with the initial Medline search. In nine studies lymph node size was measured in the short axis with CT, in one in the long axis with CT and four studies did not mention whether the short or long axis was measured.…”

“…We found 14 studies [7][8][9][10][11][12][13][14][15][16][17][18][19][20] that assessed the prevalence of metastatic involvement of enlarged lymph nodes of different size categories in patients with NSCLC. Although reports have been published that show no increase in prevalence of metastasis with increasing lymph node size or an increase at larger lymph node size (e.g.…”

“…The mean prevalence of metastatic involvement was higher in the 16-20 mm group than in the 10-15 mm group (Z-test: P < 0.001). For lymph node size group >20 mm, seven studies were found eligible [7,[10][11][12][13][14]19], for a total of 131 lymph nodes. Here the data were heterogeneous (x 2 : 35.7; P < 0.001) due to one outlier [11] ( Fig.…”

“…Individual study results of CT-based studies (reference numbers in brackets[7,[10][11][12][13][14][15]18,19]) for metastatic involvement of all lymph node size categories (error bars represent 95% CIs).…”

Endoskopische Evaluation des Mediastinums

“…Die etwas schlechtere Sensitivität spiegelt bei einer Präva-lenz von nur 39% und einer Spezifität von 100% nicht den eigentlichen Stellenwert wider [16]. Die Sensitivität des Lymphknotenstagings in Zeiten der konventionellen Mediastinoskopie konnte durch die Einführung der Videomediastinoskopie auf bis zu 96% optimiert werden ( [6,12,13,15,31,37,38]; . Tab [27].…”