. Author manuscript; available in PMC: 2014 Aug 15.

Published in final edited form as: Phys Med Biol. 2010 Nov 12;55(23):6987–6998. doi: 10.1088/0031-9155/55/23/S02

Table 2.

Excess relative risk (ERR) in each tissue (ERR_T), sum of ERR_T values over all tissues (ERR_modality) and the ratio of ERR_proton to ERR_IMRT (RRR) for various scaling factors of the radiation Weighting factor (w_R).

	ERR_T

	Nominal w_R		w_R × 0.5		w_R × 2		w_R × 5

Organ	Protons	IMRT	Protons	IMRT	Protons	IMRT	Protons	IMRT
Colon	2.25	2.73	2.11	2.73	2.52	2.73	3.33	2.73
Lung	0.05	0.02	0.02	0.02	0.10	0.02	0.24	0.02
Stomach	0.04	0.02	0.02	0.02	0.09	0.02	0.22	0.02
Bladder	3.99	6.92	3.80	6.92	4.36	6.92	5.47	6.92
Liver	0.07	0.03	0.03	0.03	0.13	0.03	0.33	0.03
Thyroid	0.01	0.00	0.00	0.00	0.01	0.00	0.03	0.00
Remainder	0.11	0.18	0.06	0.18	0.23	0.18	0.57	0.18
ERR_modality	6.50	9.90	6.10	9.90	7.40	9.90	10.20	9.90
RRR	0.66		0.61		0.75		1.03
95% CI	0.63–0.69		0.59–0.63		0.72–0.78		0.99–1.07

IMRT = intensity-modulated photon therapy; CI = confidence interval.