Table 2. Physical parameters and OAR of SBRT.

Dosimetric characteristics	Median	Range	∆rate after adaptive plan (mean %)
PTV volume, cm3	31.5	5.6–115.8	36.3
V5 of bilateral lungs, %	19.5	8.0–33.2	13.1
V10 of bilateral lungs, %	11.3	4.9–22.7	12.4
V20 of bilateral lungs, %	6.3	2.6–14.2	13.3
V30 of bilateral lungs, %	3.9	1.6–10.9	11.8
Mean heart dose, cGy	94	15.7–347	1.3
Maximum spinal cord dose, cGy	1,172.9	492.3–3,370.8	4.5
CI	0.65	0.61–0.7	NA

∆rate after adaptive plan (mean %): the percentage change in physical parameters after the adaptive plan as a percentage of the baseline plan was averaged. CI, conformity index; NA, not applicable; OAR, organ at risk; PTV, planning volume target; SBRT, stereotactic body radiotherapy.