Table 4.

The hazard ratios (HR) and p-values for the final models built in the training and validation data for predicting LR.

	Training		Validation
	HR	P-value	HR	P-value
ln(Tumour volume)	4.29	0.008	0.53	0.095
Tumour motion [cm]	1.68	0.334	1.22	0.784
Tumour location (lower lobe reference)	10.3	0.047	0.52	0.454
Age [years]	1.01	0.885	0.97	0.552
Sex (female reference)	1.4	0.619	8.36	0.059
90th percentile density -0.1 to 0.3cm from GTV [unit: 100HU]	0.02	0.013	0.27	0.057
Dose variability 0.5 to 1.6cm from GTV [Gy]	2.90	0.02	1.20	0.184
90th percentile density * Dose variability [100HU * Gy]	1.64	0.009	1.29	0.035

The bold values are those that are significant predictors in the model (p<0.05).