Which statement about radiosensitivity and differentiation is true?

• A. Radiosensitivity increases with higher differentiation
• B. Radiosensitivity independent of differentiation
• C. Radiosensitivity decreases with lower differentiation
• D. Radiosensitivity increases with lower differentiation

Answer: (D)

Radiosensitivity is higher in cells that are less differentiated because these cells are more proliferative and have more remaining divisions to go, making radiation damage more likely to affect their ability to reproduce. This aligns with the Bergonié–Tribondeau principle, which states that radiosensitivity increases with mitotic activity and decreases with the degree of differentiation. In practice, immature, undifferentiated cells tend to be the most radiosensitive, while mature, highly differentiated cells are more radioresistant. So, as differentiation decreases, radiosensitivity increases.