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Table 7 Comparisons between IMRT and VMAT for 12 brain cases

From: A treatment planning study comparing Elekta VMAT and fixed field IMRT using the varian treatment planning system eclipse

 

IMRT(n = 12)

1A(n = 12)

1Am(n = 12)

2A(n = 12)

2Am(n = 12)

PTV

     

Dmax (%)

108.1 (104.3 - 113.0)

107.8 (104.8 - 115.5)

107.2 (104.8 - 110.4)c+

107.0 (103.6 - 112.8)

106.3 (103.6 - 109.0)a+c+

V95% (%)

95.3 (90.6 - 99.3)

91.0 (75.6 - 99.2)

92.2 (83.5 - 99.2)

91.1 (75.6 - 99.8)

93.0 (81.0 - 99.8)

HI

1.09 (1.05 - 1.13)

1.14 (1.05 - 1.38)

1.11 (1.05 - 1.18)c

1.13 (1.04 - 1.35)

1.10 (1.04 - 1.19)c

CN

0.78 (0.72 - 0.86)

0.80 (0.57 - 0.93)

0.83 (0.67 - 0.93)ac

0.81 (0.56 - 0.94)

0.84 (0.65 - 0.94)ac

Body

     

Dmean (Gy)

13.5 (3.8 - 21.9)

13.2 (4.4 - 21.0)

13.1 (4.4 - 20.7)c

13.2 (4.3 - 20.9)

13.2 (4.4 - 20.9)c

V5Gy (%)

43.2 (17.7 - 62.1)

45.3 (20.8 - 63.7)a+

45.3 (21.1 - 62.0)ac

45.4 (21.1 - 62.9)a+

45.5 (21.0 - 62.4)a+c

Brain stem

     

Dmax (Gy)

50.0 (43.5 - 56.6)

53.1 (51.4 - 56.7)a

53.6 (51.3 - 56.7)ac

52.8 (51.0 - 55.1)

52.9 (51.0 - 55.1)c

Lenses

     

Dmax (Gy)

7.3 (1.0 - 49.3)

5.5 (1.5 - 11.8)

7.0 (1.5 - 31.2)a

5.7 (1.5 - 11.3)

6.9 (1.5 - 32.1)

Lens lft

     

Dmax (Gy)

4.2 (1.2 - 11.9)

5.4 (1.5 - 11.8)a+

4.9 (1.5 - 11.7)a+

5.5 (1.5 - 10.6)a

4.8 (1.5 - 11.6)a+

Lens rt

     

Dmax (Gy)

10.5 (1.0 - 49.3)

5.7 (1.5 - 11.1)

9.1 (1.5 - 31.2)

5.8 (1.5 - 11.3)

9.0 (1.5 - 32.1)

Chiasm

     

Dmax (Gy)

50.1 (43.2 - 56.7)

50.9 (32.7 - 60.7)b

51.9 (36.5 - 60.7)

50.2 (29.8 - 60.3)b

51.4 (33.4 - 60.3)

Optical nerves

     

Dmax (Gy)

43.2 (25.8 - 64.4)

40.2 (18.5 - 54.1)

41.0 (19.0 - 59.7)

39.8 (19.0 - 52.8)a

41.5 (19.7 - 60.0)

Optical nerve lft

     

Dmax (Gy)

42.3 (27.3 - 52.6)

41.4 (29.3 - 50.4)

42.1 (31.4 - 47.8)

40.9 (29.2 - 46.6)

42.3 (30.0 - 49.6)

Optical nerve rt

     

Dmax (Gy)

44.1 (25.8 - 64.4)

39.0 (18.5 - 54.1)

39.8 (19.0 - 59.7)

38.8 (19.0 - 52.8)a

40.8 (19.7 - 60.0)

MU

454.0 (330–775)

303.0 (261–342)a+

302.6 (279–342)a

293.2 (156–331)a+

293.7 (156–331)a+

  1. Single and double arc plans before (1A, 2A) and after modification (1Am, 2Am) of the optimization penalties; values are expressed as the mean (range).
  2. ap < 0.05 for Wilcoxon matched-pair signed rank test vs. IMRT; bp < 0.05 1A vs. 2A; cp < 0.05 1Am vs. 2Am; +p < 0.01.