Tumor imaging via indium 111-labeled DTPA-adenosylcobalamin

Vitamin B-12 is essential for life. Lack of it results in pernicious anemia and death, Conversely, the demand for vitamin B-12 increases in rapidly di viding tumors. This is secondary to the direct involvement of vitamin B-12 in mitochondrial metabolism as well as its indirect role in the production of thymidylate and S-adenosylmethionine. The latter 2 substances are needed for DNA synthesis and cellular methylation reactions, respectively. Novel radiolabeling of adenosylcobalamin has proven to be useful in the imaging o f transplanted and spontaneous tumors in animals. Herein, we describe what we believe to be the first human to have imaging with conventional gamma ca meras of vitamin B-12 metabolism in a breast tumor.