The annual enhanced dynamic or gated delivery dose tolerance is described as which of the following?

• A. 50 MU or expected delivery
• B. 100 MU or expected delivery
• C. 150 MU or expected delivery
• D. 200 MU or expected delivery

Answer: (B)

The key idea is that this annual tolerance uses monitor units as the measure for gating/dynamic delivery, since both gating windows and dynamic MLC motion can change how many MU are actually delivered. The standard tolerance is 100 MU, or the amount of MU that would be expected to be delivered for the planned treatment, whichever is appropriate. This keeps the QA practical: a fixed 100 MU catches meaningful discrepancies for typical plans, while for plans that are expected to deliver more MU, the tolerance reflects that actual delivery, avoiding unnecessary flags. The fixed values other than 100 MU don’t align with how these techniques vary in practice, so 100 MU (or the plan’s expected delivery) is the appropriate benchmark.