Question

What is the dose in Sv in a cancer treatment that exposes the patient to 200 Gy of γ rays?

a)0.2 Sv
b)2 Sv
c)20 Sv
d)200 Sv

Answer 1

For gamma rays, the relative biological effectiveness (RBE) is 1, hence the dose in sieverts is equal to the dose in grays. Thus, a 200 Gy exposure to gamma rays results in a dose of 200 Sv.

Step-by-step explanation:

The dose in sieverts (Sv) can be calculated from the dose in gray (Gy) by considering the relative biological effectiveness (RBE) for the radiation type. The formula to convert Gy to Sv is: Sv = Gy x RBE. For gamma rays (γ rays), the RBE is typically considered to be 1, because they are standardly used as the reference radiation type for which the RBE is set as 1. Therefore, when a patient is exposed to 200 Gy of gamma rays, the dose in sieverts is also 200 Sv, since we multiply by 1 (200 Gy x 1 = 200 Sv).