Gallium scan

<p>A gallium scan is a type of <a href="/facts/Nuclear_medicine/L9Dzjd90">nuclear medicine</a> diagnostic investigation that uses either a <a href="/facts/Gallium-67/Wk0C9DbY">gallium-67</a> (67Ga) or <a href="/facts/Gallium-68/Wk0C9DbY">gallium-68</a> (68Ga) <a href="/facts/Radiopharmaceutical/x3g6zbB6">radiopharmaceutical</a> to obtain images of a specific type of tissue, or disease state of tissue. The <a href="/facts/Gamma_emission/5Drf913J">gamma emission</a> of gallium-67 is imaged by a <a href="/facts/Gamma_camera/coGxuajk">gamma camera</a>, while the <a href="/facts/Positron_emission/psWp4bJT">positron emission</a> of gallium-68 is imaged by <a href="/facts/Positron_emission_tomography/5SmcW6qz">positron emission tomography</a> (PET). <a href="/facts/Gallium/EucevDs9">Gallium</a> <a href="/facts/Salt_(chemistry)/lsSKwGpn">salts</a> like gallium <a href="/facts/Citrate/EgKGQBdl">citrate</a> and gallium <a href="/facts/Nitrate/5AnVlYnL">nitrate</a> may be used. The form of salt is not important, since it is the freely dissolved gallium ion Ga3+ which is active. Both 67Ga and 68Ga salts have similar uptake mechanisms. Radioactive gallium(III) is rapidly bound by transferrin, which then preferentially accumulates in tumors, inflammation, and both acute and chronic infection, allowing these pathological processes to be imaged. Gallium is particularly useful in imaging <a href="/facts/Osteomyelitis/FUzsmRPf">osteomyelitis</a> that involves the spine, and in imaging older and chronic infections that may be the cause of a <a href="/facts/Fever_of_unknown_origin/B4zzRUbI">fever of unknown origin</a>. Due to lack of disease specificity, imaging with radioactive gallium(III) salts or simple complexes thereof, such as 67Ga-citrate, has gradually become less important over time and is rarely used these days.
</p><p>However, the mentioned gallium(III) radionuclides, particularly 68Ga, are frequently used as radiolabels for peptides, proteins, oligonucleotides, drugs, and drug-like substance, turning these from regular pharmaceuticals ito radiotracers. A popular class of such radiopharmaceuticals is formed by 68Ga-labeled small-molecule inhibitors for prostate-specific membrane antigen (PSMA), which are increasingly used for prostate <a href="/facts/Cancer/PVW6n1D0">cancer</a> imaging. Furthermore, Gallium-68 labeled octreotide analogs, such as 68Ga-DOTATOC, were among the first clinically successful 68Ga PET tracers and have meanwhile replaced <a href="/facts/Indium-111/b0D0r0a5">indium-111</a> labeled octreotides for diagnostic imaging of somatostatin receptor positive neuroendocrine tumors. Investigations with 68Ga-labeled peptides etc. are however not commonly referred to as 'gallium scan'. Usually they are named after the addressed target or labeled bioligand, e.g., 'PSMA scan'  or 'DOTATOC scan'.
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Gallium scan open-in-new

Gallium scan