Skip to main content

Table 3 The systematic and random errors and PTV margins in 20 patients pre- and post-correction, and post-treatment.

From: Hypofractionated radiotherapy for lung tumors with online cone beam CT guidance and active breathing control

Setup error Pre-correction
(N = 150)
Post-correction
(N = 130)
Post-treatment
(N = (67)
  LR SI AP LR SI AP LR SI AP
M -0.3 -1.74 -0.5 0.1 0.1 0.1 -0.4 0.3 0.4
Σ 3.7 5.3 3.1 0.6 0.8 0.8 1.2 1.8 1.2
σ 2.1 3.7 2.8 0.8 1.2 1.3 1.5 1.5 2.8
Msetup 9.5 14.1 8.2 1.5 2.1 2.1 3.2 4.7 3.5
  1. Abbreviations: N = number of CBCT scans; M = group mean error; Σ = SD of individual means for setup error; σ = root-mean-square of individual SD for setup error; LR = left-to-right; SI = superior-inferior; AP = anterior-posterior; Msetup = PTV margin for setup. Msetup (PTV margin) = 2.5 Σ + β√σ22p - βσp