Computed Tomography to Stage Lung Cancer: Approaching a Controversy Using Meta-analysis

Abstract

The ability of computed tomography (CT) to detect mediastinal lymph node metastases from nonsmall cell bronchogenic lung cancer is highly controversial, as evidenced by reported accuracies ranging from 0.35 to 0.95 over the past eight years. We examined all studies on this matter published between January 1980 and April 1988, both to describe the overall experience and to identify characteristics (study design and methodology and CT scan techniques) that influenced reported accuracy. Of 79 relevant publications, 37 were excluded because they were review reports, assessed small cell lung cancer, or contained insufficient evidence to construct a contingency table (CT result versus node histology). The pooled, unweighted (weighted) results based on the remaining 42 studies were as follows: sensitivity, 0.79 (0.83); specificity, 0.78 (0.81); accuracy, 0.79 (0.81). Using a node size greater than 1.0 cm to define a "positive" CT result, as compared to a smaller diameter, was associated with significantly higher specificity, 0.89 versus 0.76, and accuracy, 0.86 versus 0.75 (p less than or equal to 0.005), but not sensitivity, 0.79 versus 0.75. The observed differences in accuracy between a fourth generation CT (0.83) and either a third or a second generation CT, (0.77 and 0.78, respectively) were not significant at p less than 0.05. No characteristics, either singly or in combination, resulted in accuracies exceeding 0.86. There exists random variation of individual study results around an overall mean accuracy of only 0.79, which is marginally improved by advances in CT technology and methods. Significant advances in the noninvasive detection of lymph node metastases must await an approach fundamentally different from CT-determined node size.

Diagnostic imaging of lung cancer

“…In 1988 STAPLES et al [106] demonstrated 79% sensitivity and 65% specificity for CT using a 1-cm long axis nodal cut-off measurement. A meta-analysis in 1990 of 42 CT studies assessing mediastinal lymph node metastases from NSCLC described an overall sensitivity of 0.79, a specificity of 0.78 and an accuracy of 0.79 [107]. However, in 1992 MCLOUD et al [108] using a nodal short axis measurement of 1 cm in 143 patients, returned to less inspiring figures of 64% sensitivity and 62% specificity, respectively.…”

99mTC‐tetrofosmin scintigraphy in lung carcinoma staging and follow‐up evaluations

“…51 A classic meta-analytic review of 42 early studies documented, on average, a CT accuracy rate of 80%. 52 Recent estimates suggest more prudent figures, in the 50 -60% range in the United States and in the 60 -70% range in Europe and Japan. 53,54 According to these last data, thoracic CT might be insufficiently accurate for being the ideal preoperative staging test.…”

Validation of a Central Review Board of Staging prior to Surgery for Non-Small-Cell Lung Cancer – Impact on Prognosis: A Multicenter Study

“…were necessarily based on endoscopic and/or radiological criteria. Although these criteria are useful for daily clinical practice, the cytohistological diagnosis of cN1–2 should be considered the criterion of classificatory certainty in view of the operational characteristics of CT for mediastinal lymph nodes (sensitivity 0.79 and specificity 0.78 in meta-analytical studies [10]).…”

“…In contrast, radiographic detection of the destruction of a vertebral body has a high level of classificatory certainty. For cN categories, radiological methods may suggest tumoral involvement (using the latest-generation CT scanners), but do not have an acceptable classificatory certainty [10]. …”