Evaluation of contrast medium enhancement and [18F]-FDG uptake of liver metastasis in PET/CT prior to therapy

Abstract

To evaluate the contrast medium enhancement and [(18)F]-FDG uptake of liver metastases in patients suffering from colon or breast carcinoma prior to therapy. PET/CT (Philips Gemini) with 200MBq [(18)F]-FDG and contrast medium was performed in 50 patients with colon and 39 patients with breast carcinoma. Lesions were characterized with the presence or the absence of a rim enhancement. The area size, the HU(mean), HU(max), SUV(mean), SUV(max) of the lesion and of the liver were determined. The standard uptake values (SUVs) were correlated with the tumor markers CEA and CA 15-3. The lesions of colon carcinoma had HU(mean)-values of 70.7±19.2 and of breast carcinoma 88.1±21.7 (p<0.0001). In breast cancer the SUV(mean) was 3.9±1.3 versus 4.4±1.9 in colon carcinoma (p=0.0182). Lesion of colon carcinoma with rim enhancement had a significantly higher SUV(mean) (4.4±1.5 versus 3.6±1.2; p=0.001) and SUV(max) (6.7±2.6 versus 5.1±2.1; p=0.000) than lesions without a rim enhancement. A good correlation between tumor markers and SUVs(max) could be found in both tumor groups; r=0.83 (p<0.01) for colon carcinoma and r=0.82 (p<0.01) for breast carcinoma. The rim enhancement of the lesions in colon carcinoma indicate a significantly higher SUV.