Mean Computed Tomography Value to Predict the Tumor Invasiveness in Clinical Stage IA Lung Cancer

The purpose of this study was to validate the ability of the mean computed tomography (m-CT) value to predict tumor invasiveness and recurrence, and further, to compare with other measurements such as consolidation/tumor ratio and solid tumor size.

A retrospective study was conducted of 494 patients with clinical stage IA lung cancer who had peripherally located lung adenocarcinoma. Receiver operating characteristic curve analysis was used to compare the ability to predict tumor invasiveness and recurrence between m-CT value, consolidation/tumor ratio, and tumor size. Multiple logistic regression analyses were performed to determine the independent variables for the prediction of pathologic, less invasive lung cancer. Disease-free survival was measured from the date of the operation until any recurrence.

The m-CT values were 643.6 ± 9.4 Hounsfield units in the noninvasive cancer group and 365.9 ± 11.4 Hounsfield units in the invasive cancer group (p < 0.0001). The invasive cancer group was strongly associated with a high CT attenuation value, high consolidation/tumor ratio, large solid tumor size, large tumor size, and high standardized uptake value. Multiple logistic analyses, including the preoperatively determined variables, revealed that standardized uptake value and m-CT are independent predictive factors of less invasive lung cancer. In addition, the hazard ratio of the m-CT value was higher than that of the standardized uptake value value.

The evaluation of m-CT value is useful in predicting less invasive lung cancer. The m-CT value can potentially determine operative procedure, particularly limited resection for peripheral lung adenocarcinoma.