Table 2 Dose coverage of the breast-CTV and SIB-CTV and the in the planning CT compared and the estimated delivered dose distribution.

From: Impact of CBCT frequency on target coverage and dose to the organs at risk in adjuvant breast cancer radiotherapy

Non-hypofractionated radiotherapy (n = 45)

Planning-CT

Estimated delivered dose distribution

Daily CBCT

EOD

Weekly

Breast-CTV

Dmean

51.4 ± 1.6 Gy

49.9 ± 2 Gy

49.8 ± 2.1 Gy

49.7 ± 2.1 Gy

Daily vs. EOD

Δ − 0.1 (− 2.1; 0.7) Gy

p = 0.06

Daily vs. Weekly

Δ − 0.2 (− 2.3; 1.0) Gy

p = 0.01

V95%

85 ± 7.3%

77.4 ± 8.9%

77.1 ± 9.1%

76.8 ± 9.2%

Daily vs. EOD

Δ − 0.3 (− 6.9; 1.6) %

p = 0.13

Daily vs. Weekly

Δ0.6 (− 7.3; 2.2) %

p = 0.02

SIB-CTV

Dmean

61.8 ± 2.3 Gy

61.8 ± 2.4 Gy

61.5 ± 2.4 Gy

61.4 ± 2.4 Gy

Daily vs. EOD

Δ − 0.3 (− 1.9; 0.5) Gy

p < 0.01

Daily vs. Weekly

Δ − 0.4 (− 2.1; 0.9) Gy

p < 0.01

V95%

98.6 ± 2.8%

97.0 ± 4.7%

96.1 ± 6.2%

94.9 ± 7.6%

Daily vs. EOD

Δ0.9(10.9; 1.2)%

p = 0.07

Daily vs. Weekly

Δ2.1(− 20.1; 2.1)%

p < 0.01

Hypofractionated radiotherapy (n = 5)

Planning-CT

Estimated delivered dose distribution

Breast-CTV

Dmean

40 ± 1.3 Gy

39.4 ± 1.3 Gy

39.4 ± 1.4 Gy

39.4 ± 1.4 Gy

V95%

89.2 ± 4.9%

83.5 ± 3.6%

83.4 ± 3.8%

83.3 ± 3.8%

SIB-CTV

Dmean

47.2 ± 1.7 Gy

47.5 ± 2.4 Gy

47.5 ± 2.3 Gy

47.5 ± 2.3 Gy

V95%

99.8 ± 0.3%

97 ± 5.5%

96.9 ± 5.6%

96.5 ± 6.3%

  1. Mean values and standard deviation. Mean absolute differences between CBCT-protocols (range).