Dose-Area Product (DAP) is defined as

• A. Dose rate × time
• B. Dose × beam area
• C. Energy × area
• D. Dose × time

Answer: (B)

DAP represents the total energy delivered to the patient within the irradiated field by combining how much dose the beam delivers with how large the beam is. Specifically, it multiplies the dose in the beam by the cross-sectional area of the beam at the patient. With dose in grays and area in square centimeters, the unit is Gy·cm^2. This captures both the intensity of exposure and the extent of tissue exposed, which is why it’s used to estimate overall patient radiation burden across procedures. The description Dose × beam area is the best fit. Dose rate × time would measure exposure rate over time, not the total energy delivered across the exposed area; energy × area isn’t the standard measure for patient dose in this context; and Dose × time doesn’t incorporate the irradiated field size.