Table 4.

Summary of functional lung dose-volume parameters in patients that experienced greater than ("Deteriorating FEV1") and less than ("Stable FEV1") the median percentage decline in FEV1 at different radiotherapy dose thresholds (V5-50) and for MLD

% p20 volume	"‘Stable FEV1" (n = 21)	"Deteriorating FEV1" (n = 20)	Difference between means (%)	t-test p-value	ROC AUC (Az)
p20V5	43.8	56.0	12.2	0.050	0.68
p20V10	27.2	43.6	16.4	0.003**	0.76
p20V13	21.3	35.0	13.6	0.005**	0.74
p20V20	14.7	22.1	7.4	0.033	0.68
p20V30	10.5	13.8	3.3	0.213	0.60
p20V40	7.5	8.9	1.3	0.520	0.56
p20V50	4.5	4.8	0.3	0.797	0.55
p20MLD (cGy)	987	1310	323	0.052	0.67

AUC, area under the curve; MLD, mean lung dose; ROC, receiver operating characteristic.

Results that reach statistical significance after application of the Bonferroni correction (significance level 0.05/8 = 0.00625) are marked with**.