Table 2.

Summary of CBCT number differences of the Gammex phantom inserts between images with and without 1 cm bolus. Results of the original images, scatter‐correction processed images, and images acquired with a bowtie filter are listed for comparison. All the images were acquired with an Elekta XVI CBCT

CBCT Number Difference	Original Images	Scatter‐correction Processed Images	Images Acquired With a Bowtie Filter
Maximum	485	349	357
Mean	128	80	100
Minimum	40	4	6