How can the radiosensitivity of cells be influenced?

The radiosensitivity of cells can indeed be influenced in various ways, leading to either an increase or decrease in their sensitivity to radiation. This can occur due to several factors, including the cell's stage in the cell cycle, type of tissue, genetic influences, and the presence of certain chemicals or biological factors.

For instance, cells that are actively dividing—such as those in the gastrointestinal tract or bone marrow—typically exhibit higher radiosensitivity. Conversely, cells that are in a quiescent phase or are more differentiated, like nerve cells, generally exhibit lower radiosensitivity. Additionally, certain drugs, like radiosensitizers, can enhance radiosensitivity, while radioprotectors may decrease it by helping the cells repair damage caused by radiation.

Understanding these dynamics is crucial for medical dosimetry, as it allows practitioners to tailor radiation therapy more effectively, maximizing damage to cancerous cells while sparing healthy tissues. Thus, the radiosensitivity of cells is not fixed; it can fluctuate based on various intrinsic and extrinsic influences.