The developing placenta in selecting potential radiopharmaceuticals for tumour-localizing properties: a simple in vivo pre-screening model.

The tissue distribution of various radiopharmaceuticals was investigated in rhabdomyosarcoma-bearing and in pregnant rats during the period of rapid foetal and placental growth (days 17-19 of pregnancy). The preliminary results indicate that with the radiopharmaceuticals tested the uptake in placental tissue followed closely the data obtained with tumour tissue in rhabdomyosarcoma-bearing rats.