Combination adriamycin-radiation treatment of pulmonary tumors in mice

Different schedules of thoracic irradiation (1,000 rad single dose) and adriamycin (3.0 mg/kd/day for 3 consecutive days given i.v.) were used to treat mice bearing pulmonary microcolonies of the Dunn osteosarcoma. Lung colony numbers and volumes were scored in mice sacrificed 21--25 days after tumor cell inoculation. Significantly greater levels of tumor control were achieved when the 2 agents were given concurrently or when the irradiation preceded adriamycin by 7 days, compared to lower levels of tumor control when the adriamycin preceded the irradiation by 7 days. The sequence of administering these 2 agents appears to have little effect, however, in reducing peripheral leukocyte count.