What can digitally reconstructed radiographs (DRRs) be compared with to verify the accuracy of beam placement?

Digitally reconstructed radiographs (DRRs) serve as essential tools in radiation therapy to verify the positioning of the treatment beams. They are generated from three-dimensional volumetric data, often derived from CT scans, and provide an accurate representation of a patient's anatomy and the planned treatment setup.

Comparing DRRs with simulator films is fundamental in the verification process. Simulator films represent images taken during the simulation phase of treatment planning, where the treatment strategy is tested and confirmed before actual delivery. By overlaying the DRRs with these simulator films, clinicians can assess alignment and confirm whether the treatment beams will accurately target the intended areas, ensuring that the setup is correct before immobilization devices are applied.

While CT images, patient records, and viewing screens are indeed relevant in the broader context of treatment planning and review, they do not serve the specific function of providing a direct comparison to verify beam placement as effectively as simulator films do. Simulator films capture the exact configuration required for patient positioning and beam alignment, making them the most relevant choice for verifying the accuracy of beam placement alongside DRRs.