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Table 4 Average and standard deviations values for CBCT shifts for all fractions

From: Evaluating organ delineation, dose calculation and daily localization in an open-MRI simulation workflow for prostate cancer patients

  CT registered to CBCT MRI registered to CBCT
  AP (cm) SI (cm) LR (cm) AP (cm) SI (cm) LR (cm)
Patient 1 0.21 ± 0.28 0.04 ± 0.25 0.04 ± 0.29 −0.07 ± 0.25 0.11 ± 0.11 0.03 ± 0.27
Patient 2 0.49 ± 0.30 −0.02 ± 0.54 0.07 ± 0.36 0.44 ± 0.28 0.03 ± 0.54 0.04 ± 0.33
Patient 3 0.04 ± 0.61 0.06 ± 0.53 0.06 ± 0.51 0.01 ± 0.76 0.23 ± .58 0.01 ± 0.48
Patient 4 0.10 ± 0.23 0.18 ± 0.24 −0.08 ± 0.26 0.02 ± 0.15 0.02 ± 0.15 0.00 ± 0.00
Patient 5 0.17 ± 0.32 0.28 ± 0.22 −0.06 ± 0.36 0.27 ± 0.47 0.42 ± 0.27 −0.15 ± 0.38
Patient 6 0.26 ± 0.42 0.02 ± 0.24 0.16 ± 0.19 −0.02 ± 0.33 0.10 ± 0.20 0.10 ± 0.18
Patient 7 −0.06 ± 0.49 −0.18 ± 0.88 0.11 ± 0.64 −0.63 ± 0.49 −0.11 ± 0.86 0.15 ± 0.64
Patient 9 −0.33 ± 0.28 −0.10 ± 0.16 0.30 ± 0.25 −0.28 ± 0.29 −0.02 ± 0.11 0.29 ± 0.27
Patient 10 0.36 ± 0.30 0.05 ± 0.15 −0.32 ± 0.31 0.19 ± 0.29 0.04 ± 0.14 −0.31 ± 0.33
M 0.14 0.04 0.03 −0.01 0.09 0.02
Σ 0.24 0.14 0.17 0.31 0.15 0.17
σ 0.38 0.43 0.38 0.41 0.41 0.36
Margin 0.87 0.64 0.69 1.06 0.66 0.68
Margin 0.85 0.53 0.67 0.84 0.57 0.64
  1. M is the mean group error, Σ is the inter-patient uncertainty and σ is the inter-fraction uncertainty. The sigma values are used to calculate the needed CTV-PTV margin using the van Herk formalism.
  2. Margin not including patient 7, see discussion section.