Figure 6.

Frequency of target border LE greater than 2 mm in the LR, AP, and SI directions and in all three dimensions (3D) after simultaneous “Averaged” registration of both the primary tumor and involved lymph nodes. This registration technique involved separate alignments of each individual target volume, which were then averaged together to obtain the final transform. Nominal border alignment was defined as the transformation that minimized localization errors for opposing target borders in each cardinal direction. NMI: normalized mutual information.