Table 3.

OAR dose levels for critical structures

Organ At Risk	Patients Above Dose Level
	Mean Dose	Protons (%)	IMRT (%)
Lens (n=78)	> 2 Gy	25 (32)	64 (81)
	> 6 Gy	16 (21)	36 (46)
	> 12 Gy	10 (13)	13 (17)
Hypothalamus (n=39)	> 5 Gy	13 (33)	27 (69)
	> 16 Gy	6 (15)	12 (30)
	> 35 Gy	1 (3)	5 (15)
Pituitary (n=39)	> 20 Gy	16 (41)	21 (54)
	> 30 Gy	15 (38)	18 (46)
	> 40 Gy	10 (26)	15 (38)
Testes (n=16)	Any Dose	12 (75)	16 (100)
	> 2 Gy	4 (25)	10 (63)
	> 12 Gy	0 (0)	6 (38)
Ovaries (n=8)	Any Dose	3 (38)	8 (100)
	> 6 Gy	2 (25)	5 (63)
	> 12 Gy	1 (13)	3 (38)
Lacrimal Gland (n=78)	> 20 Gy	11 (14)	21 (27)
	> 35 Gy	3 (4)	9 (12)
	> 45 Gy	3 (4)	5 (6)
Growth Plates (n=24)	> 10 Gy	8 (33)	19 (79)
	> 20 Gy	6 (25)	8 (33)
	> 30 Gy	4 (17)	6 (25)