I'm sorry your partner is going through this. I know how disheartening it is when the first line of treatment doesn't act as you hoped it would. Fortunately there are many good treatment options, prrt being one of them. Sometimes its a combination of therapies that work together that gets a good result, like prrt and lanreotide. Also lanreotide with everolimus and captem with lanreotide have been studied.
Is your partner seeing a net specialist?