PT - JOURNAL ARTICLE AU - Dinesh Shetty AU - Jae Min Jeong AU - Chang Ju AU - Young Kim AU - Yun Lee AU - Dong Lee AU - June Chung AU - Myung Lee TI - 68Ga-labeled alanine derivatives as a novel PET agent for cancer imaging DP - 2009 May 01 TA - Journal of Nuclear Medicine PG - 1921--1921 VI - 50 IP - supplement 2 4099 - http://jnm.snmjournals.org/content/50/supplement_2/1921.short 4100 - http://jnm.snmjournals.org/content/50/supplement_2/1921.full SO - J Nucl Med2009 May 01; 50 AB - 1921 Objectives Various amino acids labeled with 18F and 11C for PET are used. However, they require expensive cyclotron and complicate synthesis procedure. We developed alanine derivatives, NOTA-ala and DOTA-ala, for labeling with 68Ga, a generator nuclide. Methods Protected β-amino-L-alanine was synthesizedstarting from tBoc-L-serine methyl ester by mesyl protection, azide formation and catalytic reduction. And then it was conjugated to NOTA and DOTA in aqueous solution using EDC as a coupling agent. Protecting groups were removed by lithium hydroxide (4 eq) and hydrochloric acid (30%), successively. The final products were obtained as HCl salts by HPLC purification. DOTA-ala (26.3 µg) and NOTA-ala (21.3 µg) were labeled with 68Ga in pH 3.7~5.2. Labeling efficiencies were checked by ITLC. Biodistribution and PET imaging studies were performed using balb/c mice xenografted with CT-26. Results Both DOTA-ala and NOTA-ala were labeled with 68Ga in high yields (>98%). In biodistribution study, tumor uptakes were 3.3 and 2.9% ID/g at 10 min and 2.8 and 2.5% ID/g at 60 min for 68Ga-DOTA-ala and 68Ga-NOTA-ala, respectively. The tumor to muscle and tumor to blood uptake ratio showed significantly higher value for 68Ga-NOTA-ala than 68Ga-DOTA-ala. Micro PET images for both labeled compounds showed a high bladder activity at 1 h. High uptakes were found in tumors along with kidney on 2 h images comparing to other organs. Conclusions We synthesized 68Ga labeled amino acid derivatives for tumor PET which can be labeled by one step reaction within 10 min. The NOTA-ala derivatives showed high tumor uptakes in biodistribution and animal PET studies.