Which window setting is best for estimating pathological invasive size and invasiveness?

Abstract

BACKGROUND\nIn the 8th Edition of the Tumor Node Metastasis Classification System for Lung Cancer, the definitions of the clinical T and pathologic T descriptors have changed. Little has been reported on comparisons between the consolidation diameter in the lung window setting and the tumor diameter in the mediastinal window setting with respect to the correlations with pathological invasive size (IS) and invasiveness. The purpose of the present study was to clarify which window setting was better for preoperatively estimating IS and invasiveness.\n\n\nMETHODS\nWe retrospectively reviewed 1167 consecutive patients with lung adenocarcinomas measuring ≤3 cm in diameter. We measured three high-resolution computed tomography variables. We examined correlations of IS with the three high-resolution computed tomography variables, factors predictive of a IS of ≤5 mm, and other variables related to invasiveness.\n\n\nRESULTS\nOn receiver operating characteristic curve analysis, the tumor diameter in the mediastinal window setting more strongly predicted IS than did the consolidation diameter in the lung window setting (p<0.001), and the consolidation diameter in the lung window setting more strongly predicted IS than did the maximum tumor diameter in the lung window setting (p<0.001). Lymphatic, vascular, and pleural invasion were best predicted by the tumor diameter in the mediastinal window setting.\n\n\nCONCLUSIONS\nWe can estimate IS and other variables related to invasiveness most precisely by measuring the tumor diameter in the mediastinal window setting. The tumor diameter in the mediastinal window setting is an important variable that we should measure preoperatively.