Is salvage SBRT an option for focal recurrence of PCa after prior proton therapy for intermediate-risk disease?

Yes, it is an option. There is a great need for randomized trials in the setting of local-only recurrence after definitive RT, and we do not know the optimal approach. The MASTER systematic review and meta-analysis is a good summary (Valle et al., PMID 33309278). I do not think that protons vs. phot...