Table 1.

Institutional dose constraints for single-, three-, and five-fraction SBRT

Structure	Single fraction	Three fractions	Five fractions
Spinal cord	Dmax < 14 Gy	Dmax < 21.9 Gy	Dmax < 30 Gy
	≤ 10% at 10 Gy	≤ 10% at 18 Gy	≤ 10% at 23 Gy
	≤ 0.35 cc at 10 Gy	≤ 0.35 cc at 18 Gy	≤ 0.35 cc at 23 Gy
	≤ 1.2 cc at 7 Gy	≤ 1.2 cc at 12.3 Gy	≤ 1.2 cc at 14.5 Gy
	≤ 0.03 cc at 12.4 Gy	≤ 0.03 cc at 20.3 Gy	≤ 0.03 cc at 25.3 Gy
Cauda equina	≤ 5 cc at 14 Gy	≤ 5 cc 21.9 Gy	≤ 5 cc at 30 Gy
	≤ 0.03 cc at 16 Gy	≤ 0.03 cc at 24 Gy	≤ 0.03 cc at 32 Gy
Esophagus	Dmax < 15.4 Gy	Dmax < 25.2 Gy	Dmax < 35 Gy
	≤ 5 cc at 11.9 Gy	≤ 5 cc at 17.7 Gy	≤ 5 cc at 19.5 Gy

SBRT stereotactic body radiotherapy; D_max maximum point dose to the organ