Adaptive Radiation Therapy for Head and Neck Cancer—Can an Old Goal Evolve into a New Standard?

Figure 2

Anatomic changes can be pronounced during treatment. In this example, planning CT scan and CTV contours are shown on the left. On the right, a mid-course CT (three weeks into treatment) demonstrates significant reduction in gross tumor (thick red line). Baseline CTVs have been overlaid via rigid image registration. These match current anatomy poorly and in fact extend past the skin contour into air.