@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.

@jeffmarc What is the point of waiting? For primary treatment ROs routinely treat local SV, lymph, etc. in higher risk cases without any PSMA confirmation that there is any cancer outside the prostate. They just know from experience that it is highly likely to be there with Gleason 8 or even 4+3. The same could be done for RP patients on first recurrence since there is even better information about the stage of the disease, positive margins, etc. If no ADT is done with the radiation another PSMA scan can be done after the treatment if the PSA does not become undetectable. Once ADT is removed from the initial BCR treatment follow on PSMAs can find any additional spots as fast as waiting with less risk for the majority of patients. Kwon stated that only 1/3 of patients had recurrence ONLY in the prostate bed. For the first BCR the percentage that had recurrence only in prostate bed, PV, local lymph nodes will be much higher.