188Tc

Technetium-188 (¹⁸⁸Tc) is a radioactive isotope of technetium, a synthetic element with the symbol Tc and atomic number 43. It is a beta emitter with a half-life of approximately 4.21 hours, making it useful for short-term medical imaging and therapeutic applications. Due to its short half-life, ¹⁸⁸Tc decays rapidly, reducing radiation exposure to patients.

¹⁸⁸Tc is primarily produced through neutron activation of molybdenum-98 (⁹⁸Mo), a stable isotope, in nuclear reactors. The reaction produces molybdenum-99 (⁹⁹Mo), which then decays into ¹⁸⁸Tc. This process allows for the generation of high-specific-activity ¹⁸⁸Tc, making it suitable for medical applications. The isotope is often supplied as a generator system, where ¹⁸⁸Tc is eluted from the decayed ⁹⁹Mo.

In medicine, ¹⁸⁸Tc is commonly used in radiopharmaceuticals for diagnostic imaging, particularly in bone scintigraphy, myocardial perfusion imaging, and renal scans. Its gamma emission (140.5 keV) is well-suited for single-photon emission computed tomography (SPECT). Additionally, ¹⁸⁸Tc has therapeutic potential, particularly in the treatment of neuroendocrine tumors, where it can be combined with radiolabeled peptides like somatostatin analogs.

The use of ¹⁸⁸Tc in medicine is regulated by national and international health authorities to ensure safe handling and administration. Its short half-life minimizes radiation dose to patients, while its decay products, including stable ruthenium-188 (¹⁸⁸Ru), pose minimal long-term toxicity. Research continues to explore further therapeutic applications, including targeted alpha therapy and brachytherapy, where ¹⁸⁸Tc’s decay characteristics may offer advantages over longer-lived radionuclides.