What will happen to beam output if a flattening filter is misaligned?

When a flattening filter in a linear accelerator is misaligned, it can lead to an inconsistency in the distribution of the radiation beam output. The flattening filter is designed to create a uniform beam profile across the treatment field, which is crucial for delivering the accurate dose to the tumor while minimizing exposure to surrounding healthy tissue.

If the filter is not properly aligned, the radiation intensity may vary in different areas of the beam, leading to hot spots (areas of higher dose) and cold spots (areas of lower dose). This inconsistently distributed output can jeopardize the treatment plan and effectiveness, as patients rely on the precision of the dose delivery. Such variations can result in underdosing or overdosing specific areas, which could adversely affect treatment outcomes and increase the risk of side effects.

Thus, a misalignment of the flattening filter fundamentally alters the expected beam characteristics, which is why the correct answer highlights that the output may become inconsistent.