Thallium stress test - amount of radioisotope

Should the amount of radioisotope injected depend on the patient's size and weight?  I am only 5'2" and have often been overmedicated with other drugs that haven't been adjusted for my small size.  

[Cleveland Clinic]

We inject a very small amount of drug because we actually don't want it to distribute to the other tissues as that may affect our ability to interpret the test.  So no, your weight has no impact on the isotope.  What matters is the amount of radioactivity of the isotope and its halflife.