PSMA is such an attractive point ('Achilles heel') for developing therapies. Many other than Pluvicto are under consideration. For instance, one can use a 'bullet' like the one mentioned above (Cu-67), but other approaches use Actinium-225 as the radioactive 'bullet'.
https://www.scientificamerican.com/article/this-potential-cancer-treatment-requires-modern-alchemy/#:~:text=although%20many%20radioactive%20isotopes%20exist,job%20and%20then%20decaying%20away.