. Author manuscript; available in PMC: 2013 Oct 1.

Published in final edited form as: Radiother Oncol. 2012 Jun 8;105(1):41–48. doi: 10.1016/j.radonc.2012.05.002

Table 2. Univariate regression analysis of pre-treatment FDG PET images fit to 3 month post-treatment FDG images for a linear model versus a linear mixture model.

Estimated Regression Coefficient and Hypothesis Test		Regression Models
		Single-fit Linear	Mixed-fit Linear
		Single-fit Linear	CR	NR
FDG_pre	β_{FDG, pop}	0.22 ± 0.11	0.13 ± 0.08	0.30 ± 0.10
FDG_pre	p for β_{FDG, pop} = 0	0.07	0.16	0.02

R²		0.17	0.52

Means and standard errors of regression coefficients in the mixture model were calculated for the complete responding (CR) and non-responding (NR) voxel subpopulations. Bolded p values are considered significant. R² for each model was determined by averaging individual patient z scores.