Figure 2.

An example of motion management for 5-field IMRT delivery using (A) NI with manual setup, (B) PMI1 (low imaging frequency—imaging before the first, third, and fifth field) with manual correction, (C) PMI2 (high imaging frequency—imaging before each field) with manual correction, and (D) AMI strategy. Magenta curves represent the actual 3D displacement of the target and the blue curve in (D) represents the 3D displacement estimated using the cine MV images. The red circle symbols show the time at which kV imaging occurred according to the different estimation algorithms, and the green square symbols denote the couch repositioning events determined by simultaneous MV-kV triangulation. AMI indicates adaptive monitoring and intervention; IMRT, intensity-modulated radiation therapy; NI, no intervention; PMI, periodic monitoring and intervention.