ABSTRACT
Studies were initiated at Oak Ridge National Laboratory (ORNL) in 1982 for the radiolabeling of resin microspheres with yttrium-90 (90Y) for liver cancer therapy. Yttrium-90 is the decay product of strontium-90 (90Sr). Subsequently, 90Y became a major radioisotope of choice for labeling antibodies for therapeutic trials in the treatment of other forms of cancer. A 25-Ci 90Y 90Y generator or 90Sr cow was placed in service to supply the anticipated needs of customers. In vivo use of 90Y required that the 90Sr contamination levels be kept below 10 muCi/Ci 90Y (corrected to preparation time). Also, it was necessary to remove trace metals that interfered in the 90Y antibody radiolabeling process, giving low radiolabeling yields. Di-(2-ethylhexyl) phosphoric acid (HDEHP) in dodecane has been used routinely at ORNL to extract 90Y and thereby give a product that meets the radiochemical purity required with respect to 90Sr. Methods were also developed to remove interfering trace elements to provide acceptable labeling yields.
Subject(s)
Yttrium Radioisotopes , Isotope Labeling , Radiochemistry , Yttrium Radioisotopes/analysis , Yttrium Radioisotopes/therapeutic useABSTRACT
Carrier-free beta-[103,106Ru] ruthenocenylalanine was prepared from 103, 106RuCl3 by utilizing ( ruthenocenylmethyl )trimethylammonium iodide as the key synthetic intermediate. The amino acid analogue was evaluated as a pancreatic imaging agent, but no selective uptake in the pancreas was observed in either rats or mice.
Subject(s)
Alanine/analogs & derivatives , Alanine/chemical synthesis , Organometallic Compounds , Ruthenium/chemical synthesis , Alanine/pharmacology , Animals , Female , Gas Chromatography-Mass Spectrometry , Pancreas/diagnostic imaging , Radionuclide Imaging , Rats , Rats, Inbred F344 , Ruthenium/pharmacologyABSTRACT
Selenium-75-labeled 24-(isopropylseleno)chol-5-en-3 beta-ol (4) has been prepared by reaction of sodium isopropyl-[75Se]selenol [( 75Se]2) with 3 beta-acetoxy-24-bromochol-5-ene (3). This new 75Se-labeled adrenal imaging agent shows pronounced adrenal uptake in rats. The concentration of radioactivity in rat adrenals increased steadily from 1 to 24 h after injection and then decreased slowly over the 21-day period. After 3 days the adrenal/blood and adrenal/liver ratios were 85:1 and 32:1, respectively, which are sufficient for adrenal imaging by single photon techniques. After 6 h the adrenal/blood ratio was 17:1 and the adrenal/liver ratio was 7:1. We propose that these ratios are sufficiently high for positron emission tomography of the adrenals. The absorbed radiation dose values to human organs have been estimated for the 75Se- and 73Se-labeled agent.
