Table 2 Average dose-volumetric parameters of the planning target volume, spinal cord, planning organ at risk volume of spinal cord, and 1.5-cm ring structure surrounding PTV for cervical and thoracic spine stereotactic ablative radiotherapy plans

PTV

Volume (cm³)

51.46 ± 40.92

-

D_98% (Gy)

13.50 ± 1.40

13.68 ± 1.16

0.167

D_90% (Gy)

17.01 ± 0.56

16.79 ± 0.51

< 0.0001

D_5% (Gy)

19.30 ± 0.35

19.98 ± 0.60

< 0.0001

D_2% (Gy)

19.43 ± 0.37

20.15 ± 0.62

< 0.0001

Maximum dose (Gy)

20.25 ± 0.66

20.99 ± 0.83

< 0.0001

Minimum dose (Gy)

8.71 ± 1.44

8.40 ± 1.85

0.141

Mean dose (Gy)

18.29 ± 0.14

18.63 ± 0.28

< 0.0001

CI

0.90 ± 0.07

0.82 ± 0.10

< 0.0001

HI

0.32 ± 0.09

0.35 ± 0.08

< 0.001

Spinal cord

Volume (cm³)

2.51 ± 0.72

-

D_1.2 cc (Gy)

4.52 ± 0.92

5.37 ± 1.44

< 0.0001

D_0.35 cc (Gy)

6.51 ± 0.79

8.18 ± 1.20

< 0.0001

D_0.035 cc (Gy)

7.86 ± 0.77

9.88 ± 1.13

< 0.0001

Maximum dose (Gy)

9.04 ± 0.79

11.08 ± 1.20

< 0.0001

Mean dose (Gy)

4.58 ± 0.60

5.52 ± 0.93

< 0.0001

Spinal cord PRV

Volume (cm³)

5.07 ± 1.38

D_1.2 cc (Gy)

7.26 ± 0.86

8.55 ± 1.25

< 0.0001

D_0.35 cc (Gy)

9.26 ± 0.70

10.78 ± 1.12

< 0.0001

D_0.035 cc (Gy)

10.88 ± 0.65

12.59 ± 1.09

< 0.0001

Maximum dose (Gy)

12.25 ± 0.86

13.83 ± 1.25

< 0.0001

Mean dose (Gy)

5.31 ± 0.64

6.11 ± 0.94

< 0.0001

Ring_1.5 cm

V_105% (cm³)

0.44 ± 0.61

2.66 ± 3.14

< 0.001

V_110% (cm³)

0.02 ± 0.06

0.63 ± 1.50

0.039

V_115% (cm³)

0.00 ± 0.00

0.13 ± 0.45

0.154