What is the significance of tissue oxygenation in radiation therapy?

The significance of tissue oxygenation in radiation therapy lies in its role as a radiosensitizer. When oxygen is present in tissues that are being irradiated, it enhances the effectiveness of the radiation treatment against cancer cells. This occurs due to several mechanisms.

First, oxygen increases the formation of free radicals when radiation interacts with tissue. These free radicals can cause damage to DNA, which is one of the primary targets of radiation therapy. The presence of oxygen effectively enhances the damage inflicted on cancer cells because it prevents the repair of this damage, making it more difficult for the cells to survive and proliferate.

Furthermore, hypoxic (low-oxygen) tumor environments are often more resistant to radiation treatment because cells in these areas are less likely to be affected by the radiation. Therefore, maximizing oxygen levels around the tumor can improve treatment outcomes, making oxygen a crucial factor in optimizing the effectiveness of radiation therapy. This understanding emphasizes the importance of ensuring sufficient tissue oxygenation in the planning and delivery of radiation treatments.