Fig. 8.
Standard deviation of the intrafraction dose variation due to organ motion presented for the sin(x), sin4(x), and sin6(x) motion, where X axis represent the ratio of delivery time to breathing period (DB). As an example, for breathing period of 4 s and dose rate of 500 MU/min, a DB value of 1 or 0.5 corresponds approximately to 33 or 17 MU intensity per beam segment.