A new quantitative method to evaluate the biodistribution of a radiolabelled tracer for melanoma using whole-body cryosectioning and a gaseous detector: comparison with conventional tissue combustion technology.

摘要

Whole-body autoradiography (WBA) and multi-wire proportional counting allow for spatial imaging of the radioactive material present in the tissues and organs of dehydrated animal sections. AMBIS 4000 counting of whole-body cryosections offers a sensitive, accurate and reproducible novel method for the quantitative measurement of the tissue distribution of a [14C] radiopharmaceutical. Intensity of AMBIS 4000 counting (net cpm/mm2) and concentration of radioactivity (nCi/g) were linearly related, yielding a standard curve. Evaluating biodistribution (a) provides pharmacokinetic data for predicting the potential tissue deposition of an absorbed dose of radioactivity in man, and (b) allows visual and quantitative evaluation of radioactivity in small anatomical structures that otherwise could not be detected by conventional tissue combustion technology. This new method of WBA, coupled with AMBIS 4000 counting, should prove a valuable method for pharmacodynamic studies, and afford a predictive tool for nuclear medicine by assessing specific targeting of selected tissues.