@jeffmarc Dr. Kwon’s position was that if you can’t see the recurrent cancer in the PSMA PET scan, then you don’t know where to target the radiation. Thus his desire to “….have the PSA rise to the point where they have metastasis show up in the PSMA PET scans before they do something…”

I’ve seen patient postings in various forums mention that their radiation oncologists zapped the prostate bed anyway - while not knowing where the recurrence was - because (post-prostatectomy) that’s where recurrence was most likely to happen. Yet, Dr. Kwon’s position was that “…. only 1/3 of men who have recurrence following prostatectomy have recurrence only in the prostate bed; they SHOULD NOT get salvage radiation there unless they’re absolutely certain of the location of recurrence; first confirm where the recurrence is.” (See his presentation at: https://youtu.be/Q2joD360_pI. His specific statement on this is at about timestamp 3:10.)

So, when and where to treat recurrence seems to depend on one’s RO’s philosophy regarding post-prostatectomy recurrence.