Soichi Akata MD, Presenter: Nothing to Disclose

Hisashi Saji, Abstract Co-Author: Nothing to Disclose

Jun Matsubayashi, Abstract Co-Author: Nothing to Disclose

Jinho Park MD, PhD, Abstract Co-Author: Nothing to Disclose

Toshitaka Nagao, Abstract Co-Author: Nothing to Disclose

Norihiko Ikeda, Abstract Co-Author: Nothing to Disclose

It is known that in adenocarcinoma of the lung, GGO tumors have a better prognosis than solid type tumors. The aim of this study is to determine whether it is more useful to evaluate the whole tumor size or that of only the solid component size, i.e. excepting areas of ground glass opacity (GGO), on preoperative high-resolution computed tomography (HRCT) to predict the pathologic malignancy degree of tumors in lung adenocarcinoma 7 cm or less.

Using preoperative HRCT data of 277 patients with adenocarcinoma 7 cm or less who underwent curative surgical resection from January 2005 to December 2007, we retrospectively measured the whole tumor sizes and solid component size. The whole tumor and solid component sizes with lung window setting (WTLW and SCLW) and whole tumor sizes with a mediastinal window setting (WTMW) on HRCT were compared with the pathological findings.

The mean WTLW, SCLW and WTMW were 2.58, 1.94 and 1.80 cm, respectively. There was significant correlation between the WTLW and that measured on pathological specimens (r=0.516, P<0.0001). The SCLW and WTMW values significantly correlated with the area of pathologically confirmed invasion (r=0.513, P<0.0001 and r=0.543, P<0.0001, respectively). The receiver operating characteristics (ROC) area under the curve for WTLW, SCLW and WTMW used to identify lymph node metastasis were 0.709, 0791 and 0.805, respectively. The ROC areas for WTLW, SCLW and WTMW used to identify vascular or lymphatic or pleural invasion were 0.693, 0.824 and 0.831, respectively.

On HRCT, the size of the solid component of adenocarcinomas, excluding the area of GGO, was more significant than the size of the whole tumor in evaluating pathologic malignancy degree, in terms of lymph node metastasis and vascular, lymphatic, or pleural invasion in lung adenocarcinomas 7 cm or less in whole tumor size.

Our trial may form the new conception of the T factor in the TNM classification of lung cancer.

Akata, S, Saji, H, Matsubayashi, J, Park, J, Nagao, T, Ikeda, N, Relationship between Whole Tumor Size and Solid Component Size on High-Resolution Computed Tomography Concerning the Prediction of the Degree of Pathologic Malignancy in Primary Lung Adenocarcinoma.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12029824.html