What happens to the sensitivity of tissues after radiation therapy?

After radiation therapy, the sensitivity of tissues generally increases for subsequent exposures. This is because the initial treatment can cause damage to the cellular structure and DNA within the targeted tissues, making them more susceptible to additional radiation. The mechanisms that lead to increased sensitivity may include impaired repair mechanisms and altered cellular responses due to the previous damage inflicted by radiation.

In cases where cells have already been subjected to radiation, they may not recover as effectively from future doses, resulting in a heightened reaction compared to tissues that have not previously been exposed. Understanding this is crucial in clinical practice to minimize the risk of exacerbated damage in previously treated areas and to make informed decisions regarding follow-up treatments.

The other options imply varying levels of insensitivity or unchanged conditions, but these do not accurately reflect the biological response of tissues following radiation exposure, which typically involves increased vulnerability to additional radiation.