Should a pet scan show any cancer?

Metabolism: A pet scan is a measure of brain areas metabolism. Brain tumors have a unique metabolic picture and alter the normal metabolic pattern of the affective area.

A few exceptions: A pet scan is a very good study to detect most types of cancer throughout the body. However, as with most studies, there are a few exceptions. Cancers that are extremely small (very roughy less than 1-2 cm) and or cancers that are indolent (extremely slow growing) will not necessarily show up. I hope this helps answer your question.

Dr Singer agreed

No: Size matters: with current pet systems, the limit of resolution for detecting typical cancers by 18f-fdg pet generally ranges between a 0.4- and 1.0-cm diameter, which translates into a tumor size roughly of 0.1–0.5 to 1.0 g or 10^8 - 10^9 cells. Type matters: 18f-fdg pet is typically better for faster growing, more aggressive cancers and not good for indolent cancer such as prostate.

Glucose: Pet scan relies on the theory that tumors utilize a significant amount of glucose. Many different types of cancer can show up on pet scan but certain types of cancer are much more FDG avid. Low grade tumors usually have much less uptake than high grade tumors. In addition, mucinous neoplasms often do not have much FDG uptake. Small size tumors or micrometastases also may not show up on pet.

Dr Mehranpour agreed

No: It shows lots of things