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Table 5 Plan parameters stratified by patient

From: Multi-institutional comparison of volumetric modulated arc therapy vs. intensity-modulated radiation therapy for head-and-neck cancer: a planning study

  

Patient Technique

1

2

3

4

5

PTVboost

CI95

VMAT

1.37 ± 0.03

1.41 ± 0.06

1.46 ± 0.10

1.30 ± 0.03

1.31 ± 0.03

IMRT

1.54 ± 0.09

1.44 ± 0.04

1.50 ± 0.07

1.33 ± 0.05

1.42 ± 0.17

PTVtotal

CI95

VMAT

1.43 ± 0.06

1.58 ± 0.07

1.52 ± 0.04

1.57 ± 0.08

1.40 ± 0.04

IMRT

1.53 ± 0.04

1.71 ± 0.09

1.63 ± 0.06

1.67 ± 0.10

1.57 ± 0.11

Spinal cord

D1% (Gy)

VMAT

42.1 ± 5.5

44.7 ± 2.6

43.4 ± 3.5

44.0 ± 4.1

42.9 ± 3.6

IMRT

43.8 ± 4.3

44.3 ± 2.9

44.8 ± 2.4

44.5 ± 4.7

44.4 ± 4.2

Brain stem

D1% (Gy)

VMAT

48.3 ± 4.7

42.1 ± 6.0

45.5 ± 5.6

41.4 ± 6.9

41.7 ± 5.0

IMRT

48.2 ± 1.9

45.7 ± 4.3

47.6 ± 4.2

40.5 ± 3.6

37.9 ± 5.0

Parotid gland ipsilateral

Dmean (Gy)

VMAT

21.7 ± 2.0

30.3 ± 4.9

24.8 ± 3.5

38.1 ± 9.2

25.1 ± 2.4

IMRT

23.6 ± 1.7

33.3 ± 3.5

30.5 ± 10.2

41.8 ± 11.0

26.3 ± 3.2

Parotid gland contralateral

Dmean (Gy)

VMAT

21.1 ± 1.9

23.1 ± 1.0

22.1 ± 2.1

25.0 ± 2.9

18.6 ± 1.9

IMRT

23.2 ± 1.9

24.1 ± 1.3

24.2 ± 0.5

25.3 ± 3.5

19.4 ± 1.5

Submandibular gland contralateral

Dmean (Gy)

VMAT

49.2 ± 6.0

55.0 ± 6.3

--

--

54.8 ± 4.3

IMRT

49.6 ± 5.6

57.4 ± 6.4

--

--

55.7 ± 3.7

Oral cavity

Dmean (Gy)

VMAT

31.3 ± 4.8

34.7 ± 5.4

33.3 ± 7.0

47.7 ± 1.7

36.5 ± 7.4

IMRT

34.2 ± 4.8

38.2 ± 3.1

37.4 ± 8.9

48.8 ± 1.7

38.7 ± 7.2

Larynx

Dmean (Gy)

VMAT

43.2 ± 4.4

44.9 ± 7.3

47.1 ± 4.6

46.8 ± 5.5

45.3 ± 5.5

IMRT

44.5 ± 4.3

45.5 ± 5.8

47.5 ± 4.2

47.7 ± 4.7

47.0 ± 3.9

Pharyngeal constrictors°

Dmean (Gy)

VMAT

42.3 ± 3.9

50.5 ± 6.6

48.9 ± 2.6

48.0 ± 4.9

45.7 ± 5.2

IMRT

42.1 ± 2.7

48.2 ± 3.7

49.3 ± 2.3

47.9 ± 3.6

46.9 ± 2.6

Mandible°

Dmean (Gy)

VMAT

41.7 ± 1.3

45.1 ± 1.4

55.2 ± 1.7

54.2 ± 1.5

46.7 ± 1.7

IMRT

42.4 ± 0.9

47.2 ± 1.2

57.6 ± 1.5

55.2 ± 1.6

48.9 ± 1.7

Effective delivery time

(min:sec)

VMAT

5:38 ± 0:42

6:00 ± 0:48

6:22 ± 1:28

6:07 ± 1:31

5:26 ± 1:04

IMRT

12:52 ± 0:41

13:09 ± 2:18

13:46 ± 1:07

13:30 ± 1:50

12:57 ± 2:23

MUs

--

VMAT

581 ± 55

641 ± 90

735 ± 170

668 ± 91

589 ± 73

  

IMRT

702 ± 92

836 ± 166

975 ± 125

855 ± 100

773 ± 142

  1. Pairs in bold denote statistically significant differences between VMAT and IMRT.
  2. Pairs in italic denote that the averaged plan parameter is better for IMRT.
  3. ° Not all institutes used objectives to control dose for these structures.