Kaplan-Meier survival curves of survival (reported in fractional survival) as a function of time for animas receiving varying radiation doses (solid lines) with 95% confidence intervals (dashed lines). Panel A: Survival of 9L-tumored control rats (n = 30, red) and those treated with 20 Gy (n = 22, black). Panel B: Survival of 9L-tumored control rats (n = 30, red) and those treated with 25 Gy (n = 64, black). Panel C: Survival of U-251N-tumored control rats (n = 23, red) and those treated with 20 Gy (n = 43, black). The time scale in panel A differs from that in panels B and C.