Breastfeeding and PET-CT Scans — How Long You Need to Pause

No. Milk expressed during the 12-hour pause contains FDG and must be discarded, not stored. It is still worth expressing during the pause to protect your supply — but that milk cannot be given to your baby. Only milk expressed before the tracer was injected, or after the 12-hour pause is complete, is safe to use.

This is worth planning for well before your appointment, not on the day. If your baby is not used to a bottle, introduce one gently in the days beforehand. A familiar carer offering a bottle in a calm setting is more likely to work than trying it for the first time during a stressful pause window. Speak to your lactation consultant or midwife for practical strategies — this situation comes up often, and there are approaches that help.

Yes. The restriction is specifically on breastfeeding — not on physical closeness. You can hold, carry, and cuddle your baby normally throughout the pause window. The concern is the FDG in your milk being ingested, not proximity to you. The low level of radioactivity from your body falls quickly after injection, and skin-to-skin contact is fine.

The scan itself does not affect your supply. What can affect it is stopping expressing during the pause. If you express and discard milk throughout the 12-hour window, you keep the signal to your body to continue producing. Most women who resume feeding promptly after the pause do not notice a lasting change in supply.

Not necessarily, and not in early-stage disease. NCCN and ESMO guidelines do not recommend PET-CT as a routine scan for early breast cancer. It is used in specific situations — staging locally advanced or metastatic disease, or assessing treatment response — where the information changes clinical decisions. If you have been referred, ask your oncologist what the scan is expected to show and how it will affect your treatment plan.

Aim to have at least enough to cover your baby's feeds for the full 12-hour pause. Building up a frozen supply in the days before your scan gives you time without pressure. Milk expressed before your tracer injection is completely safe to store. For guidance on how long expressed milk keeps in the fridge or freezer and how to thaw it safely, follow current WHO guidance or ask your lactation consultant — recommendations are updated periodically and your consultant will have the current advice.