The feasibility of evaluating radiation dose to the heart by integrating kilovoltage-cone beam computed tomography in stereotactic body radiotherapy of early non-small-cell lung cancer patients

Table 1 Dose-volume indices between CBCT and CT

Parameter	CBCT, ± SEM	CT, ± SEM	t	P
V_5Gy-R^a	47.7 ± 16.4%	49.0 ± 16.0%	1.5	0.17
V_10Gy-R	18.9 ± 11.7%	17.4 ± 11.8%	2.3	0.03
V_15Gy-R	14.4 ± 10.2%	12.8 ± 10.4%	2.3	0.02
V_20Gy-R	10.5 ± 9.0%	9.0 ± 8.9%	2.3	0.04
V_25Gy-R	6.6 ± 2.8%	4.5 ± 2.3%	3.6	0.01
V_30Gy-R	4.2 ± 2.2%	2.5 ± 1.6%	3.7	0.01
V_35Gy-R	3.2 ± 1.8%	1.7 ± 1.3%	3.9	0.01
V_5Gy-A^b	333.0 ± 78.4 _cm³	282.0 ± 61.7 _cm³	7.9	0.0001
V_10Gy-A	133.0 ± 68.6 _cm³	101.0 ± 59.0 _cm³	6.8	0.0001
V_15Gy-A	102.0 ± 62.6 _cm³	74.6 ± 53.7 _cm³	6.2	0.0001
V_20Gy-A	74.0 ± 55.8 _cm³	52.5 ± 46.4 _cm³	4.8	0.0001
V_25Gy-A	46.0 ± 16.9 _cm³	27.0 ± 12.0 _cm³	6.2	0.0001
V_30Gy-A	30.0 ± 14.4 _cm³	15.0 ± 8.7 _cm³	5.5	0.0001
V_35Gy-A	24.0 ± 12.0 _cm³	10.0 ± 7.0 _cm³	5.5	0.0001
D_50cm³^c	19.9 ± 7.7 _Gy	17.1 ± 6.3 _Gy	4.5	0.0001
D_100cm³	15.3 ± 6.2 _Gy	12.8 ± 5.7 _Gy	3.6	0.003
D_150cm³	11.8 ± 5.5 _Gy	9.2 ± 3.4 _Gy	3.6	0.003
D_200cm³	8.2 ± 2.0 _Gy	6.8 ± 1.5 _Gy	6.2	0.0001
D_250cm³	6.4 ± 1.7 _Gy	5.2 ± 2.0 _Gy	6.5	0.0001
D_mean	7.0 ± 2.8 _Gy	6.5 ± 2.4 _Gy	3.0	0.009
D_max	45.7 ± 13.1 _Gy	45.1 ± 13.5 _Gy	2.9	0.009

a). V_5Gy-R means the heart relative volume in the 5Gy region, V_10Gy-R, V_15Gy-R, V_20Gy-R, V_25Gy-R, V_30Gy-R, and V_35Gy-R are of the same mean;
b). V_5Gy-A means the heart absolute volume in the 5Gy region, V_10Gy-A, V_15Gy-A, V_20Gy-A, V_25Gy-A, V_30Gy-A, and V_35Gy-A are of the same mean;
c). D_50cm³ means the exposure dose in the 50 cm³, D_100cm³, D_150cm³, D_200cm³, and D_250cm³ are of the same mean.

ISSN: 1748-717X