Correlation between dynamic CT findings and pathological prognostic factors of small lung adenocarcinoma

Abstract

Purpose: To compare pathological prognostic factors of small lung adenocarcinomas with findings of contrast- enhanced dynamic computed tomography (CT) scans. Materials and methods: We evaluated 108 patients with lung adenocarcinomas ≤30mm in diameter who underwent dynamic CT scans (80-96 ml of contrast material, 2.5-3 ml/s injection) and tumor resections. Attenuation values of both the early phase (20-36 s after injection) and delayed phase (91-95 s) of enhanced CT minus baseline plain CT attenuation were defined as ΔEarly and ΔDelay. The early enhancement ratio was defined as ΔEarly/ΔDelayx100 (%). We statistically compared the early enhancement ratios between the presence and absence of each pathological finding (lymph node metastasis, lymphatic permeation, vascular invasion, and pleural involvement). Patients were divided into 2 groups based on early enhancement ratios: ratio ≥50% (n=41) and ratio <50% (n=67) and we statistically compared these 2 groups. Results: The early enhancement ratios in the group with lymph node metastasis, lymphatic permeation, and vascular invasion were significantly lower than in the group without these findings (24.9% vs 48.6%; P<0.001, 30.0% vs 47.5%; P=0.002, and 26.5% vs 47.0%; P=0.002, respectively). Lymph node metastasis, lymphatic permeation, and vascular invasion were significantly more frequent in tumors with a ratio <50% than in tumors with ratio ≥50% (P<0.001, P=0.008, and P=0.005, respectively). Conclusions: There was a significant correlation between the early enhancement ratio of enhanced dynamic CT and the pathological prognostic factors in small lung adenocarcinomas. © 2012 International Cancer Imaging Society.