What is the highest dose organ associated with Tc pyrophosphate?

• A. Heart with significant amyloidosis
• B. Liver
• C. Kidney
• D. Large intestines

Answer: (A)

The correct answer highlights the correlation between technetium pyrophosphate (Tc-PYP) and its distribution in the body, particularly when evaluating conditions like amyloidosis. In cases of significant amyloidosis, the heart tends to accumulate Tc-PYP more than other organs. This is primarily due to the characteristic deposit of amyloid proteins within the cardiac tissue, which leads to a higher uptake of the radiopharmaceutical.

When evaluating the biodistribution of Tc-PYP, significant attention is paid to the heart's affinity for this radiotracer under specific pathophysiological conditions. In such situations, the heart reflects the highest radiation dose absorbed, as the radiopharmaceutical tends to bind to abnormal amyloid deposits.

While the liver, kidneys, and large intestines are involved in the distribution of many radiopharmaceuticals, their interaction with Tc-PYP does not exhibit the same level of organ-specific uptake associated with cardiac amyloidosis. Therefore, the significant concentration of this radiotracer in the context of significant amyloidosis leads to the heart being recognized as the organ with the highest dose when using Tc pyrophosphate.