Lu-177 radioligand therapy is a major strategic use case, but it is not a simple "more patients = more Lu mined" link. The constraints can be upstream (reactor time, target material pathways, processing capacity, QA, logistics).
OECD-NEA work on medical radioisotopes highlights the emergence and demand growth of therapeutic isotopes like Lu-177, and also flags ongoing uncertainty about supply meeting demand.
There is also published discussion of real-world supply vulnerabilities for key isotopes including Lu-177.
One important nuance: Some high-profile supply tightness has eased at times (example: Novartis stated the US drug shortage for Pluvicto was resolved and discussed capacity expansion), which shows that "shortage" is not a permanent state.