If the primary beam area is doubled by opening the collimator, how will this affect patient dose and operator exposure?

Doubling the primary beam area by opening the collimator significantly impacts patient dose and operator exposure due to the inverse square law and the principles of radiation exposure. When the area of the beam is increased, a larger volume of tissue is irradiated which, in turn, results in a higher dose being delivered to the patient.

Radiation dose is not just a function of exposure; it’s also related to how much area the beam is covering. When the area of exposure doubles, the amount of scattered radiation increases as well, further contributing to the dose received by both the patient and the operator. Consequently, this could lead to an increase in exposure proportional to the area, which is typically understood to be related to the square of the distance from the source. Thus, a doubling of the beam area theoretically results in an increase in dose by a factor of four, if we consider that the intensity of radiation can increase due to scattering and the larger area being irradiated.

Since option D indicates an increase by a factor of 2, rather than the expected increase of a different multiplier, there might be a misunderstanding, and the correct interpretation leads towards an increase that reflects the compounding factors of beam area and radiation behavior rather than just doubling. This is