Table 1.

Cell killing dose-response fitting parameters.

	α (Gy−1)	β (Gy−2)
X ray irradiation	0.222 ± 0.062	0.064 ± 0.014
Proton irradiation in the absence of BSH	0.314 ± 0.022	0.035 ± 0.007
Proton irradiation with 40 ppm 11B	0.614 ± 0.069	—
Proton irradiation with 80 ppm 11B	0.705 ± 0.033	—

Calculated values for the α and β parameters as obtained from the fitting of experimental data by the linear-quadratic model for radiation-induced cell killing are reported. Statistically equivalent to zero β values were found for proton irradiation in the presence of BSH.