Radiation-induced meningeal and pituitary tumors in the rat after prenatal application of strontium-90.

Strontium-90 was inject i.v. into pregnant rats on day 18 post conception (p.c.). This caused a remarkable transplacental radioactivity uptake and accumulation in the ossification centers of the skull basis. The total radiation dose within the surface of these regions was consequently calculated to be 0.6-1.2 Gy within the entire lifespan. About 50% of it was delivered during the 7 days following the injection of the isotope. The pathologic examination of the offspring throughout their lifetime revealed a pituitary tumor frequency in the exposed groups which was about tenfold in the males and threefold in the females in comparison to the controls. A very outstanding result in the animals treated was the occurrence of metastasizing meningeal sarcomas in about 6% of all cases. In four cases (= 2%) the simultaneous occurrence of a pituitary adenoma and of a meningeal sarcoma could be observed.