Table II.

Comparison of target coverage and normal tissue sparing: dose-volume metrics of 4D treatment plans after 3D optimization and after 4D optimization for each patient. The prescribed dose is 74 Gy.

Patient	Optimization	$D_{95\%}^{\text{PTV}}$	$D_{\max }^{\text{PTV}}$	$D_{\text{mean}}^{\text{PTV}}$	MLD	$V_{20\hspace{0.17em}\text{Gy}}^{\text{Lungs}}$	$V_{30\hspace{0.17em}\text{Gy}}^{\text{Lungs}}$	$D_{\max }^{\text{Esophagus}}$	$D_{\text{mean}}^{\text{Esophagus}}$	$V_{55\hspace{0.17em}\text{Gy}}^{\text{Esophagus}}$	$D_{\max }^{\text{Cord}}$	$D_{0.1\%}^{\text{Cord}}$	$D_{\max }^{\text{Heart}}$	$D_{\text{mean}}^{\text{Heart}}$	$V_{40\hspace{0.17em}\text{Gy}}^{\text{Heart}}$	$D_{\text{mean}}^{\text{Skin}-\text{PTV}}$
A	3D	71.6	78.3	74.5	10.1	16.9	11.3	31.6	12.3	0	2.7	2.1	54.6	16.3	7.5	5.8
	4D	72.7	80.0	74.8	10.3	17.3	11.5	32.0	12.6	0	2.7	2.2	55.8	16.7	8.3	6.0
B	3D	63.6	85.7	75.6	19.9	30.1	24.8	72.1	18.7	8.8	46.0	44.6	78.5	37.8	50.7	10.5
	4D	65.3	86.5	75.8	20.8	31.2	25.8	73.3	19.4	9.5	46.7	45.2	78.7	38.2	52.1	10.5
C	3D	73.1	84.6	77.7	7.7	14.3	9.4	76.9	13.6	3.1	34.6	33.8	27.2	1.2	0	5.0
	4D	71.6	81.6	75.8	7.5	14.9	9.0	76.2	13.6	2.8	35.0	33.9	24.5	1.1	0	4.8

D_mean and D_max represent the dose received by mean and maximum volume of the PTV or OARs, respectively; MLD the mean lung dose; D_A% the dose received by A% of volume of the PTV or OARs (Gy); and V_BGy the fractional volume of OARs receiving at least B Gy (%).