We studied X-ray response, thermal radiosensitization, and time sequencing between heat and radiation for nontolerant and thermotolerant murine bone marrow cells. Survival curves of colony-forming units of granulocyte-macrophages (CFU-GM) have a D0value of 1.26 ± 0.04 Gy when irradiated in vivo. Heating at 44°C for 30 min immediately prior to X-ray yields a D0value of 0.96 Gy, with a thermal enhancement ratio of 1.3. Similar D0and thermal enhancement ratio values were seen for thermotolerant cells. In vitro experiments with CFU-GM gave similar results. Studies of the effect of time sequence on heat and radiation indicate that for CFU-GM, the interaction between the two modalities do not fully disappear when given within 180 min of each other. Colony-forming units of erythrocytes (CFU-E) irradiated in vivo shows a D0value of 1.1 ± 0.03 Gy for radiation alone. Heating at 44°C for 25 min prior to irradiation gives a D0value of 0.95 Gy (thermal enhancement ratio, 1.1). Again, there was no change in the D0value of radiation alone or the combination of heat and radiation in thermotolerant CFU-E. Both radiation killing and thermal radiosensitization were the same for thermotolerant and nontolerant CFU-GM and CFU-E.
|Original language||English (US)|
|Number of pages||4|
|State||Published - Jan 1 1987|
ASJC Scopus subject areas
- Cancer Research