Table 1.

Dosimetric comparison of IMRT-SIB and IMPT plans

			Treatment Plans
Organ	IMRT		Proton AP/PA			Proton LPO/RPO			Proton AP/LPO/RPO
	Mean	S.E.	Mean	S.E.	p value*	Mean	S.E.	p value*	Mean	S.E.	p value*
GTV
Mean dose, Gy	67.90	0.20	68.50	0.40	0.3	68.60	0.35	0.17	68.50	0.34	0.29
Lung
Mean dose, Gy	8.27	1.01	3.18	0.51	<0.0001	4.90	0.69	0.001	4.30	0.64	0.0002
V5, %	38	5	12	2	<0.0001	19	2	0.0002	19	3	0.0003
V10, %	23	3	10	2	0.0001	15	2	0.004	15	2	0.005
V20, %	14	2	7	1	0.0006	11	2	0.15	7	1	0.0008
Heart
Mean dose, Gy	21.20	1.58	19.90	1.52	0.31	11.90	0.98	<0.0001	17.00	1.33	0.003
V10, %	79	4	66	5	0.0342	29	2	<0.0001	61	4	0.0044
V20, %	44	4	46	5	0.71	22	2	0.0001	29	3	0.0003
V30, %	25	3	23	2	0.18	17	2	0.002	20	2	0.01
V40, %	15	2	15	2	0.94	13	1	0.07	14	2	0.35
V50, %	8	1	9	1	0.12	8	1	0.60	9	1	0.15
Liver
Mean dose, Gy	14.90	1.48	4.90	0.60	<0.0001	5.00	0.63	<0.0001	5.40	0.63	<0.0001
V20, %	26	3	12	2	0.0010	9	1	0.0002	9	1	0.0001
V30, %	13	2	7	1	0.0006	6	1	0.0004	7	1	0.0005
V40, %	7	1	5	1	0.007	5	1	0.004	5	1	0.004
V50, %	4	1	3	1	0.06	3	1	0.07	3	1	0.04
Spinal Cord
Maximum dose, Gy	36.70	3.01	24.80	0.47	0.004	36.80	3.74	0.97	24.70	1.19	0.0008
Maximum dose to 1 cm3, Gy	34.30	2.84	22.80	0.35	0.01	34.35	2.11	0.99	20.73	0.89	0.002

^*vs. IMRT plan

Abbreviations: IMRT-SIB, intensity-modulated [photon] therapy with simultaneous integrated boost; IMPT, intensity-modulated proton therapy; AP/PA, anteroposterior/posteroanterior; LPO/RPO, left posterior oblique/left posterior oblique; S.E., standard error; GTV, gross tumor volume