To limit stochastic effects, which statements are true for dose management?

• A. 1 and 2
• B. 1 and 3
• C. 2 and 3
• D. 1, 2, and 3

Answer: (C)

Stochastic effects (like cancer) have no safe dose threshold—the risk increases as the dose increases. Because of that, dose management focuses on applying methods that reduce the amount of radiation absorbed or delivered to tissues, i.e., ALARA.

Shielding directly lowers the dose reaching sensitive tissues by attenuating the beam, which reduces the probability of stochastic effects. Reducing exposure time and/or increasing distance from the source also cuts dose, since less time irradiates tissue and the dose falls off with distance according to the inverse square law.

If a statement suggests that stochastic risk has a threshold or isn’t affected by dose reduction, it isn’t consistent with how stochastic effects behave. The statements that describe reducing dose—through shielding and time/distance optimization—are the ones that correctly reflect dose management to limit stochastic risk.