What should the radiation oncologist mark on each CT slice?

The radiation oncologist marks the planning target area (PTA) on each CT slice to delineate the specific region that requires radiation treatment. The PTA is a crucial component of treatment planning, as it identifies the volume where the tumor is located and encompasses any surrounding tissues that need to be treated to ensure effective therapy. Accurately marking the PTA allows for precise targeting during treatment, optimizing dose delivery while minimizing exposure to surrounding healthy tissues.

Effective delineation of the PTA also supports communication among the treatment team members, including dosimetrists and radiation therapists, ensuring that everyone is aligned on the area that requires attention throughout the treatment course. This practice ultimately enhances the safety and efficacy of the radiation therapy being administered.

Other aspects, such as marking the scan length, treatment modality, or patient position, while important, do not carry the same critical relevance as marking the PTA in the context of ensuring a precise and effective treatment plan.