In radiation therapy, what is a common side effect caused by radiation damage to normal tissues?

Radiation therapy often targets rapidly dividing cancer cells, but it can also affect normal tissues that have a high turnover rate, such as those in the lining of the gastrointestinal tract, bone marrow, and skin. The common side effect of sensitivity and damage to rapidly dividing cells occurs because these normal cells are more susceptible to the effects of radiation. This is due to their inherent biological characteristics; their rapid proliferation means they are often in a state of active division when exposed to radiation, making them vulnerable to the damaging effects on their DNA.

This damage can manifest as various side effects, including mucositis, skin reactions, and changes in blood cell counts, which can lead to symptoms like fatigue and increased risk of infections. Understanding this mechanism is crucial for managing side effects in patients undergoing radiation therapy and highlights the challenges of selectively targeting cancerous cells while sparing normal tissues.