How can setup errors or reproducibility issues be detected?

Detecting setup errors or reproducibility issues is crucial in ensuring the accuracy and effectiveness of radiation therapy. The most reliable method involves comparing simulator film with port film or electronic portal imaging device (EPID) images. This process allows dosimetrists and therapists to visualize the actual patient positioning relative to the planned treatment position captured during simulation.

When the images from these various setups are analyzed, discrepancies can be identified, indicating potential setup errors. This visual comparison helps ensure that the radiation beams are aligned correctly with the tumor, minimizing exposure to surrounding healthy tissues. It serves as a practical verification step to confirm that the patient's setup remains consistent throughout the treatment course.

While patient feedback during treatment can provide subjective insight into comfort and perceived positioning, it does not offer precise measurements necessary for identifying subtle errors. Monitoring dosimetry readings is critical for evaluating dose delivery but may not directly indicate position reproducibility. Using standardized patient protocols is essential for maintaining treatment consistency and quality assurance but does not specifically address the detection of setup errors as directly as the imaging comparison does.