What is the main purpose of using compensating filters in radiation therapy?

The main purpose of using compensating filters in radiation therapy is to compensate for surface irregularities. In clinical practice, patient anatomy can vary significantly from the planned treatment geometry, which can lead to heterogeneous dose distribution if not properly managed. Compensating filters are designed to modify the radiation beam's profile, effectively adjusting the dose received by different regions of the treatment area. This ensures that areas with irregular surfaces receive an adequate dose while protecting nearby healthy tissues.

By employing compensating filters, clinicians can achieve a more uniform dose distribution, which is particularly important in complex geometries where direct dose calculations might not accurately reflect the treatment delivered. This technique allows for better clinical outcomes and improved patient safety, as it helps to deliver the intended therapeutic dose to the tumor while sparing surrounding normal tissues.