Table 2.

Comparision of target coverage metrics for the PTV as a function of plan modality ($\overline{x}$ ± SD)

Metric	3DCRT	for-IMRT	inv-IMRT	HT	VMAT	p-value
Dmax (Gy)	55.94 ± 1.34	55.01 ± 1.30	54.16 ± 0.54	53.85 ± 0.66	55.08 ± 0.72	<0.001
Dmean (Gy)	51.86 ± 1.04	51.66 ± 1.00	51.18 ± 0.36	50.85 ± 0.22	51.35 ± 0.40	0.019
V53.5 (%)	20.56 ± 15.60	13.03 ± 12.80	1.85 ± 1.77	0.39 ± 0.59	10.15 ± 2.98	<0.001
IB-V50Gy (cc)	765 ± 338	659 ± 423	696 ± 314	750 ± 376	717 ± 399	0.964
OB-V50Gy (cc)	379 ± 323	245 ± 239	103 ± 58	76 ± 51	57 ± 29	<0.001
CN	0.58 ± 0.07	0.62 ± 0.08	0.75 ± 0.05	0.80 ± 0.05	0.73 ± 0.06	<0.001
HI	0.13 ± 0.02	0.12 ± 0.07	0.09 ± 0.01	0.06 ± 0.01	0.17 ± 0.02	<0.001
MU	231 ± 29 MU	222 ± 14 MU	1245 ± 146 MU	9284 ± 354 MU	300 ± 52 MU	<0.001

D _max max dose, D _mean mean dose, V _x volume (%) receiving x dose (Gy) or higher, IB-V _50Gy prescribed dose volume (cc) inside of the PTV, OB-V _50Gy prescribed dose volume (cc) outside of the PTV, $\overline{x}$ mean dose, SD standard deviation, CN conformation number, HI homogeneity index, MU monitor unit