If a daily conebeam CT is done for prostate cancer treatments, do you subtract any treatment fractions to compensate for the daily imaging dose?

The radiation dose from daily imaging depends on techniques used. In most cases the dose of radiation is very low, relative to the dose delivered for treatment. Nonetheless, this dose is often delivered to non-targeted tissues and it is wise to minimize the dose and volume when feasible.

From my physics colleagues, here is the dose from typical daily imaging scenarios:

• a pair of 6MV portal images will induce dose 3cGy,
• a 125 kVp CBCT scan from Trilogy machine will induce dose of 1.4cGy
• a 125kVp...