Are You Radioactive — After a PET-CT Scan?

At a very low level, yes — but by the following morning the tracer has gone through several half-lives and what remains is a small fraction of what was injected. AERB guidance places the main precaution period in the first several hours after the scan. By the next day, normal contact with everyone, including pregnant women and children, is fine. If your scan was in the late afternoon and your partner is pregnant, sleeping separately for one night is the cautious approach.

Yes, but a brief hug is very different from extended close contact. A quick embrace when you arrive home is not the same as an hour with a young child on your lap or lying next to you. The precaution is specifically about prolonged, close contact — not about any touching at all. For the first few hours, keep visits short and avoid having a young child sit with you for a long period.

If your partner is not pregnant and is an adult, sleeping in the same bed is generally fine. The precaution about sleeping separately applies specifically when your partner is pregnant. If you are not sure, ask the nuclear medicine team at the imaging centre before you leave — they deal with this question every day and can give you a direct answer based on the exact time of your scan.

Possibly yes, for up to 24 hours after the scan. Airports, border crossings, and some government buildings use detectors sensitive enough to pick up the tracer. This is not dangerous — it means the detector is working as intended. Before you leave the imaging centre, ask for a letter confirming you have had a nuclear medicine scan. Carry it if you have any travel or security checkpoints planned in the next day. If you do trigger an alarm without the letter, tell security calmly that you have had a PET scan and give them the name of the centre.

The dose is real, and it is right to ask about it. A PET-CT combines radiation from the FDG tracer with the CT component. Before recommending the scan, your oncologist and the nuclear medicine team weigh this dose against what the scan is expected to tell them — about how your treatment is working, for example. For most cancer patients, that information is clearly worth the dose involved. If you want to understand the specific figures from your scan, ask the nuclear medicine physician at the imaging centre to explain them.

No, not immediately. If you are breastfeeding, you need to stop for a defined period after the scan to avoid passing the tracer to your baby. How long depends on the tracer used, and you need specific advice for your situation — not the general adult guidance. Tell the imaging centre you are breastfeeding before the scan, not after. They will tell you how long to express and discard milk. If this was not discussed before your scan, call the nuclear medicine department today.

No. The concern after a PET scan is extended close contact with pregnant women and young children — not with other adults. Other cancer patients, visitors, or people who are immunocompromised are not in the category these precautions address. Sitting in a waiting room or walking through a corridor is not the kind of contact these guidelines are about. Normal adult interaction is fine from the moment you leave the scanner.

A brief, incidental encounter — passing in a corridor, sitting nearby in a waiting room for a few minutes — does not carry the same concern as prolonged close contact over hours. If you are worried, call the nuclear medicine department at the imaging centre. They can give you an honest assessment based on the approximate distance and time involved. Do not assume the worst from an accidental moment of proximity — the question is always about duration and closeness, not any contact at all.