Sr90-Y90 extracorporeal irradiation in goats and man.

Studies on the efficacy of low (25 rads/transit) transit dose extracorporeal irradiation (ECI), using a ${\rm Sr}^{90}\text{-}{\rm Y}^{90}$ β-emitting source, were undertaken in a series of 10 goats and 3 uremic patients. In animal studies, lymphopenia could be regularly produced after 20 to 30 hours of intermittent irradiation. The histologic assessment of lymphocyte depletion was quite variable. In goats weighing more than 30 kg. the total lymphocyte mass was not measurably depleted, but in smaller animals there was striking depletion of lymphocytes from the mantel zones of lymphoid follicles and a selective preservation of germinal center cells. Two uremic patients were extensively irradiated prior to renal transplantation, but they did not show measurable lymphocyte depletion in lymph node biopsy, and the interval between transplantation and graft rejection was not prolonged. Measurements of radiation-induced chromosomal changes in lymphocytes, in all 3 irradiated patients, provided significant data i...