Table 2.

Univariate and Multivariate Cox Regression Results for PFS Controlling for Patient Age and Tumor Grade Using Continuous Measures of MRI Metrics

MRI Metrics	PFS (Univariate)			PFS (Multivariate)
2–4 Months	HR	Z-value	P-value	HR	Z-value	P-value
Posttreatment nrCBV	2.20 (0.89–5.45)	1.71	.09	N/A
%Change in nrCBV	1.02 (1.00–1.03)	2.34	.02*	1.02 (1.00–1.04)	2.18	.03*
Posttreatment ADC	0.99 (0.99–1.00)	−1.89	.06	N/A
%Change in ADC	0.95 (0.90–0.998)	−2.04	.04*	0.96 (0.91–1.01)	–1.64	.10
Posttreatment median nrCBV/ADC ratio	3.26 (1.05–21.95)	2.04	.04*	3.77 (1.17–12.14)	2.22	.03*
%Change in median nrCBV/ADC ratio	1.02 (1.00–1.03)	2.57	.01*	1.02 (1.00–1.03)	2.17	.03*
Change in FLAIR volume	0.99 (0.97–1.01)	−1.25	.21	N/A

Note: Asterisks (*) indicate P < .05.

Abbreviation: PFS, progression-free survival; nrCBV, normalized relative cerebral blood volume; ADC, apparent diffusion coefficient; FLAIR, fluid-attenuated inversion recovery; HR, hazard ratio.