What Makes a PET-CT Report — Worth Trusting?

SUV stands for standardised uptake value. It is a number that describes how intensely a particular area of the body is taking up the tracer — in most PET-CT scans, a glucose-based tracer called FDG. A higher number generally indicates more metabolic activity. The reason it matters is comparison: if your report records an SUV for a site today, your team has a baseline to measure against at your next scan. A report that describes findings only in words makes that comparison harder and more open to disagreement between clinicians.

Yes, and a missing comparison is one of the most common weaknesses in PET-CT reports. A scan in isolation tells your team what is present today. A scan compared to a named previous scan tells them whether disease is responding, stable, or progressing — which is almost always the clinical question. The comparison should name the date of the previous scan and describe explicitly what has changed at each site, not just note that a prior study exists.

FDG-avid means that area of tissue took up more of the tracer than the surrounding tissue. It is not a diagnosis on its own — FDG uptake can occur in cancer, inflammation, infection, and some normal tissues. Whether an FDG-avid area is significant depends on its location, its SUV value, how it compares to your previous scan, and the clinical context your oncologist brings to it. If your report uses this phrase without an SUV value or a comparison, ask your oncologist what those findings mean in your specific situation.

A clinically complete, structured report typically takes one to two working days. A report that arrives on the same day as the scan may have been prepared before the nuclear medicine physician has fully reviewed the images in clinical context. If you need a report urgently, your oncologist can request a priority read. What you should not trade for speed is completeness — a fast but incomplete report does not help your treatment decisions.

Your oncologist is the right person to walk you through the report, because they have your full clinical picture. The nuclear medicine physician who wrote the report reads the images in the context of what they were told when the scan was ordered. Your oncologist knows how those findings fit your treatment history and what they mean for your care plan. If the report is unclear to you, ask your oncologist to go through it section by section at your next appointment. If you cannot wait, call the clinic.

Bring the report to your oncologist and point out specifically what appears to be missing — a site that was discussed before the scan, an SUV value that is absent, or a comparison to a previous scan that was not done. Your oncologist can request an addendum from the nuclear medicine physician, or a second read if the report does not answer the clinical question it was ordered to answer. Raising the concern is the right thing to do.