The 68-Gallium PET Scan--What's the real deal?

The 68-Gallium PET Scan

There's been a lot of confusion about the gallium scan because it's confusing.  Part of it is the terminology, lots of it is from the fact that most people don't understand the details/complexity of imaging, not to mention the ins and outs of neuroendocrine itself. 

So the formal name of the test is the "68-Gallium-DOTA-SSA PET/CT".  Think of it this way, it is the next generation of Octreoscan.  It's faster, more details, higher resolution, and more sensitive.  It still looks at neuroendocrine tumors, and to be precise, the somatostatin receptor ON the tumor.

There are three parts to it.  The first is the "analogue tracer", which is the stuff they inject in your veins.  One is the SSA part (which stands for somatostatin analogue).  It's the octreotide part.  Think of it as the guided missile.  Then there's the DOTA part, which is the cage for the gallium.  Then there's the gallium, which is essentially a light bulb.  The last part is the camera that takes pictures, which is the PET scanner.  This scan has had amazing results in detecting neuroendocrine tumors that regular Pet Scans do not pick up on.  

This test should only take about two hours from injection time to scan completion.  It's ONLY available at a few centers, so when I hear people say, "Sure, we have the gallium scan", I'm extremely skeptical.  Do you know what it took for me to get it here in the U.S.!?!?!?!?

Just an FYI, the OLD, OLD, OLD gallium scan was (you're not going to believe this), an old Gallium-67 scan.  It was used to look at inflammation.  It's essentially obsolete, but you can still get it if you want.  BE CAREFUL.  THE DEVIL IS IN THE DETAILS.  Makes sure it is a PET scan, and there is a fair chance your doc has no idea what's up.  They're smart people, this is just new technology.  

Good luck.  We're making progress!

Eric Liu, M.D.
Neuroendocrine Specialist, Nashville, TN