Table 5.

Optimal cut-off values and crude rates of severe RP

	AUC (95% CI)	Cut-off values	Sensitivity	Specificity	p value
PTV/Lung	0.88 (0.78–0.95)	1.1	90.0	72.4	<0.001a
PTV volume	0.82 (0.71–0.90)	29.1	90.0	62.1	<0.001a
V20	0.76 (0.64–0.85)	4.3	80.0	69.0	0.003a
V10	0.72 (0.60–0.83)	9.7	90.0	55.2	0.012a

AUC, area under the receiver operating characteristic curve; CI, confidence interval; PTV, planning target volume; RP, radiation pneumonitis; Vn, the percentage of the total lung volume receiving more than or equal to n Gy.

^aStatistically significant.