DOTAGA-tetra (t-Bu ester) is widely used in the field of radiopharmaceuticals, particularly for the development of imaging agents in nuclear medicine. It serves as a versatile chelating agent, enabling the stable binding of radioactive metal ions such as gadolinium, lutetium, or gallium. This property makes it essential for creating contrast agents in magnetic resonance imaging (MRI) and positron emission tomography (PET) scans. Its tert-butyl ester groups provide protection during synthesis, ensuring efficient conjugation to biomolecules like peptides or antibodies. This allows for targeted imaging of specific tissues or tumors, enhancing diagnostic precision. Additionally, its stability and compatibility with various radionuclides make it a valuable tool in theranostics, combining diagnostic and therapeutic applications for diseases like cancer.