. Author manuscript; available in PMC: 2013 Aug 1.

Published in final edited form as: Int J Radiat Oncol Biol Phys. 2012 Jan 26;83(5):1528–1533. doi: 10.1016/j.ijrobp.2011.10.052

Table 2.

Comparison of Dose Metrics by LS Status: Plan-Related Spinal Cord^*

Dose metric	Non-LS (n = 34)	LS (n = 15)	p-value
Mean dose (Gy)	29.0 ± 6.9	33.6 ± 7.0	0.032
Maximum dose (Gy)	42.2 ± 4.2	43.1 ± 4.5	0.572
V₁₀ (%)	99.1 ± 2.6	99.1 ± 3.2	0.451
V₂₀ (%)	83.4 ± 22.1	89.9 ± 18.1	0.148
V₃₀ (%)	54.9 ± 35.6	76.7 ± 32.8	0.044
V₄₀ (%)	12.3 ± 17.5	32.6 ± 24.2	0.005
Vol (cc) ≥10 Gy	14.0 ± 2.0	14.3 ± 2.1	0.421
Vol (cc) ≥20 Gy	11.8 ± 3.5	13.0 ± 3.3	0.157
Vol (cc) ≥30 Gy	7.8 ± 5.2	11.1 ± 5.1	0.048
Vol (cc) ≥40 Gy	1.7 ± 2.5	5.0 ± 3.9	0.006

Defined from the skull base to the inferior border of the PTV.