Table 4 Correlations between the DVH ^a -based parameters and acute grade ≥2 RP ^b in present study (n = 23)

Total Lungs

V₅ (%)^c

36.0 ± 6.0

35.0 ± 4.0

0.141

V₁₀ (%)^c

16.0 ± 4.0

14.0 ± 2.0

0.125

V₂₀ (%)^c

4.8 ± 2.0

4.4 ± 1.2

0.696

V₃₀ (%)^c

2.0 ± 1.0

2.0 ± 1.0

0.990

MLD (Gy) ^d

3.8 ± 1.6

3.7 ± 1.3

0.077

Contralateral lungs

V₅ (%)

26.0 ± 7.0

25.0 ± 9.0

0.421

V₁₀ (%)

18.0 ± 7.0

16.0 ± 9.0

0.277

V₂₀ (%)

3.2 ± 1.1

2.4 ± 0.9

0.210

V₃₀ (%)

1.6 ± 0.5

1.6 ± 0.6

0.992

MLD (Gy)

2.8 ± 0.6

2.6 ± 0.2

0.483

Ipsilateral lungs

V₅ (%)

51.0 ± 9.1

44.0 ± 4.0

0.034

V₁₀ (%)

22.0 ± 6.0

19.0 ± 4.0

0.273

V₂₀ (%)

6.0 ± 2.8

5.2 ± 2.2

0.454

V₃₀ (%)

2.6 ± 1.0

2.8 ± 1.1

0.824

MLD (Gy)

5.9 ± 1.3

5.7 ± 1.1

0.290

PTV volume (cm ³ )

59.0 ± 9.6

45.0 ± 9.9

0.039