. Author manuscript; available in PMC: 2012 Jul 1.

Published in final edited form as: Int J Radiat Oncol Biol Phys. 2010 Oct 13;80(3):928–937. doi: 10.1016/j.ijrobp.2010.08.006

Table 3.

Variations in the depth to the distal tumor volume surface (D2DT) correlated with variations in position of the distal prescription iso-dose. (The data are for the right lateral beam only). Statistically significant correlations with the D2DT and the femur setup angle are highlighted in bold.

Case	Plan CT			In-room CT
	Proton range [mg/mm²]	SOBP mod [mg/mm²]	D2DT [mm]	D2DT range [mm]	D2DT mean ± standard deviation [mm]	Deviation in the distal iso-dose [mm]	Correlation p-value
	Proton range [mg/mm²]	SOBP mod [mg/mm²]	D2DT [mm]	D2DT range [mm]	D2DT mean ± standard deviation [mm]	Deviation in the distal iso-dose [mm]	D2DT	Femur angle
1	252	74	220 ± 1	214–228	221 ± 3	−0.4 ± 3.1	0.001	0.107
2	295	88	277 ± 2	274–290	281 ± 4	2.1 ± 2.9	0.169	0.022
3	248	65	226 ± 1	223–231	228 ± 2	2.3 ± 2.3	0.052	0.001
4	272	80	241 ± 1	237–254	244 ± 3	2.5 ± 2.0	0.023	0.199
5	224	64	202 ± 1	200–208	204 ± 2	3.0 ± 2.4	0.049	0.002
6	232	80	206 ± 1	203–212	206 ± 2	2.7 ± 2.5	0.009	0.309
7	218	92	192 ± 1	187–195	191 ± 2	−0.4 ± 2.1	0.021	0.063
8	236	86	200 ± 1	200–206	204 ± 1	−3.4 ± 1.5	0.029	0.372
9	263	75	230 ± 1	228–236	232 ± 2	−0.7 ± 1.9	0.001	0.857
10	233	76	207 ± 1	197–208	204 ± 2	2.8 ± 2.4	0.023	0.308

Abbreviations: CT = computed tomography scan, SOBP = spread-out Bragg peak, D2DT = depth to distal tumor volume surface