Staging of pulmonary metastases using dual-energy computed tomography after anti-angiogenic therapy

Abstract

Objective: The aim of this study was the evaluation of dual-energy computed tomography (DECT) for the assessment of pulmonary metastases (PM) after antiangiogentic therapy (AT).

Material and methodology: A total of 82 patients with non-small cell lung carcinoma (NSCLC), colorectal cancer (CRC), gastrointestinal stromal tumors (GIST) and hepatocellular carcinoma (HCC) were examined before and after AT with  DECT of the lung. The number, size, CT densities (HU) of the PM were determined by 2 radiologists in consens in both DECT. The Wilcoxon sign rank test was applied (SPSS, version 21, SPSS, IBM, Chicago, USA).

Results: The 82 patients (NSCLC: 32/82; CRC: 34/82; GIST: 10/82; HCC: 6/82) with a total of 201 PM were included. DECT were produced with a time interval of 4 $\pm$ 1 months. Size changes of the metastases: PM total 23 mm vs. 24 mm; p = .1/ NSCLC 22 mm vs. 23 mm; p = .2/ CRC 23 mm vs. 23 mm; p = .3/ GIST 24 mm vs. 25 mm; p = .1/ HCC 22 mm vs. 21 mm; p = .1. Contrast media in the course: PM total 45 HU vs. 25 HU; -44%; p < .05/ NSCLC 43 HU vs. 22 HU; -49%; p < .05/CRC 33 HU vs. 15 HU; -55%; p < .05/ GIST 45 HU vs. 24 HU; 47%; p < .05/HCC 62 HU vs. 43 HU; -31%, p < .05.

Conclusions: The quantification of the contrast medium uptake of pulmonary metastases is valid by using dual-energy imaging. In this way, the therapy response according to antiangiogenetic therapy with regard to the contrast medium uptake can be assessed more precisely without native imaging in addition to changes in the size of the metastases.