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

Published in final edited form as: Int J Radiat Oncol Biol Phys. 2010 Oct 8;79(1):226–232. doi: 10.1016/j.ijrobp.2010.07.1979

Table 4.

Spinal cord tolerance study parameter comparison.

Parameter	Current Study	van den Aardweg, et. al.¹⁴	Bijl, et. al.¹³
Species	Yucatan Minipig	Large White Pig	Wistar Rat
Cord Coverage	Lateral Gradient	Uniform	Lateral Gradient
Dose Rate	4.0-7.3 Gy/minute	0.21-0.30 Gy/minute	10-15 Gy/min
Energy	6MV LINAC	60-Co	150 MeV protons
Planning Images	CT	CT/fluoroscopy mix	N/A
Positioning Method	Stereoscopic xray	Conventional	Planar xray
Field Size(s)	2.5 × 5 cm (w × l)	5×10, 5×5, 5×2.5 cm (w × l)	2×2 cm
Field Arrangement	Dynamic arc	Parallel opposed	Single Posterior
Target	mid-C4 to mid-C7	C2-C5	C1-T2
Follow-up	53-58 weeks^*	70-110 weeks	52 weeks
Latency	10-23 weeks^**	7.5-16.5 weeks	18-23 weeks
Sex	Female	Female	male
Age	40-47 weeks	37-43 weeks	12-14 weeks
ED₅₀	20.0 Gy	27 Gy^***	29-33 Gy

One exception at 75 weeks.

^**

One exception at 35 weeks.

^***

Response not adjusted for low dose rate.