To determine the relative biological effectiveness (RBE) of tritiated water (HTO) compared to 250 kVp X-rays for the induction of oncological transformation in vitro, mouse C3H10T1/2 cells were exposed to doses of 35, 70, 105 and 140 cGy both for HTO beta-rays and X-rays.
The doses of HTO beta-rays were delivered at the dose rates of 10 and 1 cGy/h.
The calculated RBE values were obtained to be 1.78 ± 0.11 for the dose rate of 10 cGy/h and 1.69 ± 0.09 for 1 cGy/h.