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Table 4 Plan parameters stratified by institute

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

  

Institute Technique

A

B

C

D

E

PTVboost

CI95

VMAT

1.39

1.35

1.31

1.43

1.38

IMRT

1.43

1.42

1.37

1.55

1.47

PTVtotal

CI95

VMAT

1.51

1.49

1.54

1.45

1.51

IMRT

1.58

1.63

1.70

1.55

1.65

Spinal cord

D1% (Gy)

VMAT

39.1

45.6

47.7

41.1

43.8

IMRT

39.7

46.7

48.0

42.0

45.5

Brain stem

D1% (Gy)

VMAT

44.1

45.6

49.4

35.4

44.6

IMRT

42.9

45.8

46.9

40.0

44.4

Parotid gland ipsilateral

Dmean (Gy)

VMAT

27.6

26.6

33.3

23.2

29.3

IMRT

28.5

28.4

34.2

25.3

39.0

Parotid gland contralateral

Dmean (Gy)

VMAT

23.9

21.1

23.4

20.6

20.8

IMRT

24.8

22.7

23.6

21.5

23.6

Submandibular gland contralateral

Dmean (Gy)

VMAT

49.4

58.0

57.4

47.5

52.6

IMRT

49.1

58.6

58.1

51.1

54.3

Oral cavity

Dmean (Gy)

VMAT

40.0

35.2

41.6

30.7

36.0

IMRT

42.5

40.2

43.6

33.5

37.4

Larynx

Dmean (Gy)

VMAT

51.4

44.5

49.4

43.5

38.6

IMRT

51.5

46.3

49.1

44.5

40.9

Pharyngeal constrictors°

Dmean (Gy)

VMAT

52.0

45.0

49.8

43.9

44.7

IMRT

49.0

45.7

48.8

44.2

46.6

Mandible°

Dmean (Gy)

VMAT

48.8

48.0

50.5

47.6

48.0

IMRT

49.7

49.9

51.1

49.3

51.3

Effective delivery time

(min:sec)

VMAT

4:51

6:50

--

5:15

6:41

IMRT

11:47

12:08

--

15:04

14:00

MUs

--

VMAT

600

602

540

774

698

  

IMRT

830

670

824

841

975

  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.