I totally understand the desire for a conservative approach. While there is likely a primary somewhere, it apparently can’t be found and apparently doesn’t have the receptors for the gallium scan radiotracers to pick it up, therefore, PRRT (lutathera) won’t have any impact on the unseen primary; only the liver, assuming those showed uptake. After my husband had his primary pnet removed our only concern was the remaining liver tumors therefore we went with a localized approach and he had radioembolization to the liver. He was in his early 50’s at the time) This was wildly successful, reducing his very heavy tumor burden to close to nothing with very short lived, not severe side effects.
Watchful waiting, with octreotide (or lanreotide which is similar) may also very well be a viable option and many specialists opt for this. The decision your doctor makes has to be individualized to your mom, her specific circumstances and her wishes. Quality of life should be a big factor. I’m glad you’re seeking out a specialist. It’s so important as a general oncologist usually does not have the required knowledge to effectively treat this disease. I wish her the best of luck.