The growth and dissemination of continuously irradiated LS/B1 lymphosarcoma cells

Transplantable strain of murine lymphosarcoma growing as a free suspension in the peritoneal cavity of isologous hosts was continuously irradiated by 60Co unit at a low exposure rate of 1.2 Gy/day for 350 weeks. Long-term irradiation did not alter substantially the viability and invasiveness of tumor cells. In the host of irradiated cells the spleen mass was six times higher around the day 8. Histological sections of the spleen revealed areas of edema and hemorrhage and infiltration and proliferation of tumor cells mostly in subcapsular area. Most of the splenomegaly is considered to be due to hyperemia caused by mass of erythrocytes in dilated spleen sinuses. Continuous irradiation is supposed to lead to more pronounced sarcomatous character of LS/B1 tumor.