Does a PET Scan That Shows Lung Nodules Mean Cancer?

Frequently when a patient is found to have a lung nodule, which is literally a spot on the lung that maybe concerning for cancer, their positions may refer them for what's called a PET scan. A PET scan is a full body CAT scan, that is augmented by taking glucose which is a sugar that every cell in the the body uses, and radio labeling the glucose, so that they can see how much each cell is taking up the glucose.

Areas in the body that are abnormally active will take up glucose more than in the other cell. This is used to identify areas of concern. If a nodule is seen in the lungs it's possible that it's either a a scar or that it could be a developing cancer. A scar on a CAT scan will not take a glucose and will be negative on a PET skin.

However, cancer will be over active and will take up glucose. That being said cancers are not the only thing that are overactive, infections and inflammation can also be over active and can result in a nodule. Frequently when a patient has a positive PET scan, it means that there's an area of abnormal activities in the lungs that needs a biopsy.

Only biopsy can prove whether someone has cancer or not, not a PET scan.