The scans are a huge leap forward in the identifications of recurrence and informing treatment decisions. That being said, they do not always show where the recurrence is even with rising PSA.

For once, I was "lucky" and my Plarify scan showed where the recurrence was. That enabled my radiologist to use SBRT for MDT. However as web265 shows (I recognize that chart!), that was likely not the only place my PCa was so we added 12 months of systemic therapy to deal with the micrometastatic cancer, too small to be seen by the Plarify scan. As of today, I m five weeks out of ending this cycle of treatment if my final labs come back undetectable.

Don't quote me on this because I can't find the literature but in the dusty basement of my mind I faintly recall that PSADT may be a factor in imaging. Mine has always been < 3 months, from what you describe, yours may be >12 months, talk with your medical team.

So, decisions...
Do you wait and try again, what's the risk, would it change your treatment decision...?
Do you start hormone therapy now as a monotherapy (generally, doublet or triplet therapy is more mainstream but your clinical history may argue for monotherapy) based only on rising PSA...https://www.dovepress.com/evolution-of-androgen-deprivation-therapy-adt-and-its-new-emerging-mod-peer-reviewed-fulltext-article-RRU...?
Do you wait to start hormone therapy until you are symptomatic?
Do you do WPLN... and short term ADT, 6,1 2, 18 or 24 months...?

Part of that decision resides in factors such as co-morbiidities, life expectancy, quality versus quantity of life, your clinical data, PSADT is a big one...

Kevin