PET hates in the pea-souper.

I have a tumour the size of a pea whose behaviour is inscrutable. It's too small for x-rays or ultrasounds, or even for CT scans. It doesn't secrete hormone markers required for a labelled somastatin or octreotide scan; so only Positron Emission Tomography can penetrate the fog surrounding my pancreas. But even these PET scans struggle with my cancer.
Tumour and technology are lurking in and around my body; which one will jump out first and surprise the other?