Quantification of an External Motion Surrogate for Quality Assurance in Lung Cancer Radiation Therapy

Figure 1

Two representative examples for the respiratory waveform detected by the ExacTrac System. The IR marker position is illustrated in red. Automatically detected minima and maxima are shown with black triangles. The blue points represent the position during the beam-on state. The baseline, calculated by linear regression of the minima, is shown by a green line. A 60 s enlargement including two breathing cycles is shown for both patients on the upper right side.