11C]Choline Positron Emission Tomography in Estrogen Receptor–Positive Breast Cancer

Abstract

Novel radiotracers could potentially allow the identification of clinically aggressive tumor phenotypes. As choline metabolism increases during malignant transformation and progression of human mammary epithelial cells, we examined the ability of [(11)C]choline (CHO) positron emission tomography imaging to detect clinically aggressive phenotype in patients with estrogen receptor (ER)-positive breast cancer in vivo. CHO positron emission tomography was done in 32 individuals with primary or metastatic ER-positive breast cancer. Semiquantitative (standardized uptake value) and fully quantitative (net irreversible transfer rate constant of CHO, Ki) estimates of CHO uptake in the tumors were calculated and compared with tumor grade, size, involved nodes, and also ER, progesterone receptor, Ki-67, and human epidermal growth factor receptor-2 scores. Breast tumors were well visualized in 30 of 32 patients with good tumor background ratios. A wide range of uptake values were observed in primary and metastatic tumors. CHO uptake variables correlated well with tumor grade. For most imaging variables, a poor association was found with tumor size, ER, progesterone receptor, human epidermal growth factor receptor-2, Ki-67, and nodal status. CHO showed good uptake in most breast cancers and merits further investigation as a breast cancer imaging agent.