86P - Correlation between invasive size and solid component on CT evaluated with various conditions, and their impact on tumor aggressiveness

Date 15 April 2016
Event European Lung Cancer Conference 2016 (ELCC) 2016
Session Poster lunch
Topics Staging procedures (clinical staging)
Thoracic malignancies
Basic Principles in the Management and Treatment (of cancer)
Imaging
Presenter Yukinori Sakao
Citation Journal of Thoracic Oncology (2016) 11 (supplement 4): S57-S166. S1556-0864(16)X0004-4
Authors Y. Sakao
  • Thoracic Surgery, Aichi Cancer Center Hospital, 4648681 - Nagoya/JP

Abstract

Background

It has been reported that pathological invasive size is more correlated with prognosis than that of tumor gross size. We analyzed the correlation between invasive size and solid component on CT evaluated with various conditions, and we analyzed the correlation between variables (invasive size, solid component on CT evaluated with various conditions) and invasiveness or lymph node metastasis.

Methods

Between October 2013 and December 2014, 372 patients with lung adenocarcinomas underwent surgical resection at the Aichi Cancer Hospital. All tumors were examined using CT with thin section (1.0–2.0 mm) conditions on digital image data. We examined the patients' thin-section chest CT images and their clinicopathological records. Tumor dimension was evaluated under two different CT imaging conditions: lung window settings [LW: level = −500 Hounsfield unit (HU), width = 1500 HU) and mediastinal window setting settings [MW: level = 60, width = 350 HU]. The CT images were evaluated for the maximum tumor dimension using LW (MLW), MW (MMW) and evaluated for the tumor maximum diameter of solid component in the tumor using LW (CLW). Tumor disappearance ratio (TDR) was defined as 1 − MMW/MLW and the solid component ratio (C/T) was define as maximum tumor diameter using CLW/MLW.

Results

Correlation between invasive size and CT findings were as follows, MLW: 0.60, MMW: 0.65, CLW: 0.64, TDR: 0.41 and C/T: 0.62.

Invasiveness: Invasiveness was defined as positive when any of lymph vessels(ly), vascular (v) or pleura (pl) was invaded by the tumor. The AUC evaluated with ROC were gross tumor size: 0.74, invasive size: 0.80, CLW: 0.82, C/T: 0.72, MMW: 0.83 and TDR: 0.77. In each of ly/v/pl, the MD showed the highest AUC among the variables.

Lymph node metastasis: The AUC evaluated with ROC were gross tumor size: 0.57, invasive size: 0.80, CLW: 0.82, C/T: 0.72., MMW: 0.83 and TDR: 0.77.

Conclusions

MMW and CLW were correlated with invasive size (R = 0.65 and 0.64). The tumor invasiveness or lymph node metastasis were highly correlated with MMW and CLW as well as invasive size. In adenocarcinoma, the solid component size on CT can be a clinical size (T) criteria because of its high correlation of invasiveness and lymph node metastasis.

Clinical trial identification

Legal entity responsible for the study

Aichi Cancer Center Ethical Board

Funding

N/A

Disclosure

All authors have declared no conflicts of interest.