What is a Lung Nodule PET Scan?
The PET scan is designed to indicate whether or not a specific nodule is taking up a lot of glucose. And we turn that metabolically active, meaning it’s eating up a lot of fuel. It’s not diagnostic of cancer.
There are other things that cause lung nodules that will cause it to light up on a PET scan. Things like an active infection will typically be hot on a PET scan, just like a lung cancer will. So it doesn’t definitively define what it is that we’re dealing with. It just gives us more clues.
It’s also not always helpful when things do not light up on a PET scan. It doesn’t always make us as physicians feel completely reassured that we’re not missing a lung cancer. The reason being that there’s a size criteria for the sensitivity of a PET scan, and most radiologists will tell us if anything is less than eight millimeters, a PET scan is really difficult to determine whether or not that lung nodule at such a small size is metabolically active.
There are also a lot of lung nodules that aren’t completely solid. We term those ground glass opacities. Those can be, just like solid nodules, representative of lung cancer or representative of any number of other things such as an infection, a granuloma, a scar, and PET scan doesn’t always pick those up as adequately because they’re not 100% solid.
1. The PET scan is designed to indicate whether or not a specific nodule is taking up a lot of glucose – it’s not necessarily diagnostic of cancer.
2. It’s also not always helpful when things do not light up on a PET scan, because if anything is less than eight millimeters, it’s hard to determine whether or not that lung nodule is metabolically active.
3. There are also a lot of lung nodules that aren’t completely solid called ground glass opacities, which can be lung cancer or any number of other things.