What does the entrance dose represent in treatment planning?

In treatment planning, the entrance dose specifically refers to the dose delivered at the skin surface. This is crucial because it is the first point of contact where the radiation beam enters the body. Understanding the entrance dose is vital for ensuring that the prescribed dose covers the tumor while also taking into account the dose delivered to healthy surrounding tissues.

The entrance dose is influenced by various factors, including the energy of the radiation beam, the type of treatment machine used, and the distance from the source of radiation to the treatment area. This dose must be accurately calculated to minimize risks of skin damage while still effectively targeting the tumor.

When assessing the impact of treatments, medical dosimetrists and radiation oncologists routinely consider the entrance dose to optimize treatment plans for efficacy and safety. By focusing the treatment effectively while being aware of the potential for surface reactions, they can balance the therapeutic benefits against the risks, ensuring patient safety.