Tumor detection with carbon-11-labelled amino acids

Abstract

A comparative study of tumor detection with ten ¹¹C-labeled amino acids including four newly synthesized amino acids was carried out to find the most valuable ¹¹C-labeled amino acid for the diagnosis of cancer. ¹¹C-l-methionine showed the highest uptake by the experimental rat hepatoma AH109A (2.7% administered dose/g at 20 min, tumor to blood ratio; 11.4). The second highest uptake was of ¹¹C-aminocyclopentane-carboxylic acid (ACPC). The newly synthesized ¹¹C-dl-methyl-ACPC characteristically showed higher accumulation in tumor than in liver and the tumor to liver ratio reached 3.0 at 60 min after injection. It is suggested that ¹¹C-l-methionine and ¹¹C-dl-methyl-ACPC are useful amino acids for the diagnosis of cancer using positron emission tomography.