Would you biopsy three nodules that are 3 mm, 5 mm, and 6mm in a patient that has had 6 months of chemo post rectalresection with 0/30 and 1.2 cea lev?

It depends where loc: These nodules are quite small.Anything less than 5mm is too small to biopsy. You did not indicate their location? If these nodules are in the liver, a repeat ct scan in 6-8 weeks is another way to find out if they are benign or suspected cancer mets(if they increase in size) which may then need biopsy done.

Yes: Show them to your md to make sure but if they are new growths get a biopsy or resection.