A retrospective dosimetry study of intensity-modulated radiotherapy for nasopharyngeal carcinoma: radiation-induced brainstem injury and dose-volume analysis

Table 3 Summary of radiation brain stem injury tolerance expressed using ROC curve

Factor	Area under ROC curve	β	p value	Lower limit	Upper limit	Cutoff point	sensitivity	specificity
GTVnx D_2%	0.724	0.078	0.030	0.571	0.878	77.26	0.875	0.614
D_max	0.813	0.067	0.002	0.682	0.945	67.85	0.750	0.859
D_1%	0.818	0.068	0.002	0.685	0.952	60.75	0.875	0.803
D _0.1cc	0.818	0.064	0.002	0.692	0.944	60.76	0.875	0.752
D _1cc	0.798	0.069	0.004	0.663	0.932	54.58	0.875	0.737

D_2% near the maximum absorbed dose of GTVnx, D_max the maximum point dose of brainstem, D_1% the dose of 1% brainstem volume, D_0.1cc the maximum dose of brainstem delivered to a volume of 0.1 ml, D_1cc the maximum dose of brainstem delivered to a volume of 1.0 ml, GTVnx Gross tumor volume of nasopharyngeal primary lesions and their direct extensions
Abbreviation: ROC Receiver operating characteristic, GTV Gross tumor volume

ISSN: 1748-717X