Question: What does a radiotracer actually do?

Thomas Biggans answered on 16 Jun 2016:

The radioactive part of a tracer decays and emits radiation which we can detect using our equipment.

The pharmaceutical part of a tracer is a drug which is processed by the body in a particular way for example in PET scans we use glucose which is a sugar that is found in lots of foods.

When we inject a patient with a radiotracer their body only sees the glucose part and processes it as glucose which in this case is a metabolic reaction – your body turns glucose into energy for cells. So the glucose is processed and the radioactive part goes with it because their attached together. Now if we use our equipment to detect where the radiation is coming from we then know where the glucose is being processed. This is useful for cancer patients because tumours need alot of energy so they use alot of glucose so there is alot of radiation detected where the tumours are!

Its the same idea for the other types of scans we just use different drugs and different radioactive isotopes.