Do not assume those medial tests are safe that your doctor requests. If you don't really feel you need the test done, you might want to reconsider having it done. Mistakes happen and here is proof.
Quote:
CRITTENTON HOSPITAL MEDICAL CENTER
ROCHESTER State: MI
NRC Report Event Number: 51648
Notification Date: 01/12/2016
MEDICAL EVENT - PATIENT RECEIVED DOSE GREATER THAN PRESCRIBED
In preparation for lymphoscintigraphy, a patient was injected with 2.4 mCi of unfiltered technetium sulfur colloid (Tc-99) instead of the prescribed dose of 0.5 to 1.0 mCi.
The Radiation Safety Officer and Hospital Medical Physicist were notified. The patient's primary physician was also notified. No adverse effects to the patient are expected.
This event was caused by the administering technologist's failure to double check the dose given to the patient. The technologist has been counseled.
A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.
http://www.nrc.gov/reading-rm/doc-collections/event-status/event/2016/20160121en.html