Initial Experience with the Radiotracer Anti-1-amino-3-[18F]Fluorocyclobutane-1-Carboxylic Acid (Anti-[18F]FACBC) with PET in Renal Carcinoma

Assessment of renal masses with conventional imaging may be challenging. Anti-1-amino-3-[(18)F]fluorocyclobutane-1-carboxylic acid (anti-[18F]FACBC) is a synthetic L: -leucine analog with relatively little renal excretion. The present study examines anti-[(18)F]FACBC positron emission tomography uptake in patients with renal masses.Six patients with seven renal lesions were imaged dynamically for 2 h after injection of 10-10.9 mCi (370-403 MBq) anti-[(18)F]FACBC. Lesions were evaluated qualitatively and quantitatively and correlated with histology.Four clear cell and one Rosai-Dorfman lesion were hypo/isointense to normal cortex; two papillary lesions in the same patient were hyperintense. Mean SUV(max) +/- SD at 30 min was 2.8 +/- 0.24 for clear cell carcinomas and 4.5 +/- 1.7 for papillary cell lesions. Mean SUV(max)/SUV(mean) ratios +/- SD of lesion to normal cortex at 30 min was 1.15 +/- 0.19 for the clear cell carcinomas and 2.3 +/- 0.84 for papillary cell.In this small patient sample, relative amino acid transport compared with renal cortex is elevated in renal papillary cell carcinoma but not in clear cell carcinoma.