Depending on your status, there are novel investigational treatments for advanced prostate cancer using radioactive PSMA - typically using Lutetium PSMA or Actinium PSMA. The data from Europe has been impressive and initially they begin with Lutetium but if that doesn’t work they have had success also with Actinium.
The following site has a clinical trial in the USA using LuPSMA
https://clinicaltrials.gov/ct2/show/NCT03511664
You can also search there for other trials under prostate cancer PSMA.
Best wishes.