Which radiopharmaceutical is used to assess vesicoureteral reflux by the indirect method?

The correct choice for assessing vesicoureteral reflux by the indirect method is 99mTc pentetate. This radiopharmaceutical is commonly used in nuclear medicine for renal imaging, particularly in scenarios that assess kidney function and evaluate urinary tract abnormalities.

In the context of vesicoureteral reflux, which occurs when urine flows backward from the bladder into the ureters or kidneys, 99mTc pentetate can help visualize the kidneys and assess their function indirectly. By injecting this tracers into the patient and performing imaging, healthcare professionals can see how the tracer is excreted by the kidneys and whether it refluxes into the ureters instead of being completely drained into the bladder.

Other radiopharmaceuticals listed have different primary uses. Fluorine-18 FDG is predominantly utilized in oncology for imaging metabolic activities in cancer cells rather than for assessing urinary tract reflux. I-123 Ioflupane is used in the evaluation of Parkinson’s disease and related disorders, focusing on dopamine transporters rather than urinary function. Xe-133 gas is primarily used for lung ventilation studies, not urinary tract assessment. Thus, 99mTc pentetate stands out as the most suitable option for this particular assessment.