Late Somatic Effects in Mice after Total Lymphoid Irradiation

Late somatic effects of total lymphoid irradiation have been investigated in ${\rm BC}3{\rm F}_{1}$ mice. A total X-ray dose of 34 Gy was distributed in 17 daily fractions. The cumulative mortality curve is shifted in time because all the irradiated mice died earlier than the unirradiated controls. There was a 24% shortening of life span. A marked increase of solid tumor incidence, mostly due to skin cancers, was observed (66% vs 30%). In contrast, the incidence of malignant lymphomas was greatly reduced in irradiated mice (6% vs 49%). Furthermore, nephrosclerosis was a common finding in the irradiated group (38% vs 8%). Death-rate analysis revealed an association between life shortening and the presence of solid tumors and nephrosclerosis at death.