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Table 6 Comparison between IMRT and VMAT for 18 prostate cases with two hip implants

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

 

IMRT(n = 18)

1A(n = 18)

1Am(n = 18)

2A(n = 18)

2Am(n = 18)

PTV

     

Dmax (%)

106.6 (104.2 - 112.5)

108.8 (104.9 - 115.4)ab+

109.1 (105.5 - 119.7)ac

107.6 (104.9 - 113.4)b+

108.1 (104.9 - 116.0)c

V95% (%)

96.3 (89.2 - 100.0)

94.6 (85.4 - 99.6)

93.9 (82.7 - 99.6)a

96.2 (86.5 - 99.8)

95.6 (84.3 - 99.8)

HI

1.09 (1.05 - 1.15)

1.10 (1.05 - 1.20)b+

1.11 (1.05 - 1.23)c+

1.09 (1.04 - 1.19)b+

1.09 (1.04 - 1.22)c+

CN

0.78 (0.63 - 0.86)

0.71 (0.46 - 0.82)a

0.72 (0.44 - 0.82)a

0.71 (0.46 - 0.81)a

0.71 (0.45 - 0.81)a

Body

     

Dmean (Gy)

5.3 (3.9 - 9.0)

4.7 (3.4 - 7.2)a+

4.7 (3.4 - 7.0)a+

4.7 (3.4 - 7.2)a+

4.7 (3.4 - 7.1)a+

V5 Gy (%)

17.7 (11.4 - 29.1)

15.8 (10.3 - 23.4)a

15.8 (10.3 - 21.9)a

15.8 (10.3 - 23.2)a

15.7 (10.2 - 22.4)a

Rectum

     

V40 Gy (%)

57.0 (38.9 - 70.1)

62.2 (55.9 - 76.5)a+

61.5 (55.9 - 72.7)a

62.5 (57.4 - 78.9)a+

61.9 (57.4 - 75.8)a

V60 Gy (%)

28.1 (18.8 - 42.3)

35.8 (14.7 - 53.7)a+

34.2 (13.9 - 51.5)a+

36.2 (21.2 - 56.4)a+

36.0 (21.2 - 54.8)a+

V70 Gy (%)

4.2 (0.0 - 12.7)

6.6 (0.0 - 24.4)

5.7 (0.0 - 19.8)c

7.0 (0.0 - 25.5)a+

6.3 (0.0 - 21.3)a+c

Dmax (Gy)

72.5 (66.7 - 77.7)

73.5 (68.8 - 78.3)

73.4 (68.0 - 78.4)

73.3 (68.1 - 77.5)

73.4 (68.2 - 77.5)

Bladder

     

V40 Gy (%)

37.2 (20.5 - 76.5)

37.9 (23.0 - 68.1)

37.1 (23.0 - 63.9)

37.5 (24.2 - 63.1)

37.9 (24.2 - 69.7)

V60 Gy (%)

19.1 (9.3 - 38.2)

20.0 (10.3 - 38.9)

19.2 (10.9 - 40.7)

20.4 (11.7 - 40.4)

20.3 (10.3 - 40.3)

V70 Gy (%)

6.1 (0.0 - 21.3)

6.5 (0.0 - 25.5)

6.0 (0.0 - 27.5)

7.0 (0.0 - 27.8)

6.5 (0.0 - 28.2)

Dmax (Gy)

73.9 (67.4 - 79.9)

75.6 (69.0 - 83.7)a+

75.4 (69.9 - 83.8)a

75.0 (69.5 - 81.9)a

74.9 (68.1 - 81.5)a+

Implants

     

Dmax (Gy)

25.6 (4.3 - 74.4)

13.2 (3.5 - 66.7)a+

13.3 (3.6 - 67.4)a+

13.3 (3.3 - 67.7)a+

13.4 (3.5 - 66.7)a+

Dmean (Gy)

3.2 (0.9 - 8.1)

1.9 (0.7 - 6.0)a+

1.9 (0.7 - 6.0)a+

1.9 (0.7 - 6.6)a+

1.9 (0.7 - 6.6)a+

MU

585.3 (435–761)

488.1 (436–595)ab

491.4 (424–595)ac+

536.0 (410–701)b

556.1 (415–744)c+

  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.