Table 3.

Model parameter values for white matter necrosis. The best estimates of the parameter values are given with their 68% confidence intervals. The values of the Log-likelihood function, χ², degrees-of-freedom (DF) and probability of χ² distribution (P_χ) that describe the goodness-of-fit of the models to the experimental data, with and without accounting for the volume effect. The inter-comparison of the models is performed, the AIC measure and the F-test, using the Lyman model as reference (with the volume effect).

Name of the model	D50 (Gy)	γ50	Volume parameters	Volume effect	Log likelihood	χ2	DF	Pχ	AIC	F-test
Critical volume	20.7 (20.3–21.2)	3.20 (2.6–3.3)	M = 20 (18–21) N = 397 (320–431)	With	−35.6	12.75	10	0.24	20.75	0.57
				Without	−32.0	4.57	8	0.80	16.57	0.92
Relative seriality	21.3 (21.1–21.5)	4.0 (3.6–4.4)	s = 0.01 (0.01–0.01)	With	−35.3	14.09	11	0.23	20.09	0.63
				Without	−31.9	4.84	8	0.77	16.84	0.93
Inverse tumor	19.5 (17.5–21.5)	1.0 (0.8–1.2)	k = −3.1 (−3.6–−2.5)	With	−40.2	16.89	11	0.11	22.89	0.73
				Without	−31.9	4.84	8	0.77	16.84	0.96
Critical element	24.2 (23.1–26.0)	1.0 (0.7–1.3)	s = 1.0	With	−47.3	25.76	12	0.01	29.76	0.90
				Without	−31.9	4.84	8	0.77	16.84	0.99
Lyman (Gaussian) Reference model	21.0 (20.5–21.7)	4.0 (3.3–4.7)	n = 0.62 (0.58–0.66)	With	−36.0	11.46	11	0.41	17.46	0.50
				Without	−33.4	5.56	8	0.70	17.56	0.84
Parallel architecture	21.2 (18.0–30.4)	3.9 (3.2–5.1)	v50 = 0.14 (0.13–0.16) σv = 0.03 (0.02–0.03)	With	−34.3	11.52	10	0.32	19.52	0.51
				Without	−32.1	5.02	8	0.76	17.02	0.87
Weibull distribution	22.8 (22.6–23.4)	3.2 (2.5–4.0)	b = 0.63 (0.59–0.66)	With	−35.4	10.33	11	0.50	16.33	0.43
				Without	−31.6	4.26	8	0.83	16.26	0.89