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Table 2 Systematic errors

From: Potentials of on-line repositioning based on implanted fiducial markers and electronic portal imaging in prostate cancer radiotherapy

  Mean ± SD [mm] j = 1,..., 23 Range [mm] j = 1,..., 23
Systematic setup error <Δs>j   
Left-right 0.8 ± 1.6 -2.9/3.9
Superior-inferior 0.1 ± 2.1 -2.7/6.2
Anterior-posterior -1.2 ± 2.4 -5/4.1
Systematic prostate movement <Δm>j   
Left-right -0.3 ± 1.1 -2.9/2.7
Superior-inferior 0.9 ± 1.9 -3.1/4.7
Anterior-posterior 0.3 ± 2.3 -4.3/5.0
Systematic total error <Δtot>j   
Left-right 0.5 ± 2.0 -2.6/6.6
Superior-inferior 0.9 ± 2.7 -4.3/7.3
Anterior-posterior -0.8 ± 2.6 -6.7/4.0
  1. Analysis of the mean vectorial setup errors per patient (after averaging over i = 1,..., 8 weekly controls) (1/8)Σi = 1...8 Δsij =: <Δs>j, the mean vectorial prostate movements (1/8)Σi = 1...8 Δmij =: <Δm>j and the mean vectorial total errors (1/8)Σi = 1...8 Δtotij =: <Δtot>j. After statistical analysis with respect to j = 1 to 23 patients we achieve the population based (mean) vectorial systematic error defined as (1/23)Σj = 1...23<Δs>j, (1/23)Σj = 1...23<Δm>j and (1/23)Σj = 1...23<Δtot>j splitted in the RL, SI and AP direction and the standard deviation SD from these errors (see Fig. 2 for explanation of symbols). Also the range (minimum to maximum) is listed (right row).