flare after SBRT to single bone met? How long until PSA goes to zero?

[Manilo]

did Lu177 with PSA .03 and prostate,Limph nodes, and one bone metastasis

All lesions disappeared in PET PSMA scan 9 months later

except one bone Mets that went from SuvMAX 4 to 23 , and PSA from .30 to 5.5

We did SBRT to the rib.

Does anyone have experience on a PSA flare after SBRT?

Does PSA go to zero inmediately or takes some time?ow long?

thanks 🙄🤞

[GP24]

It will take several weeks until you get the nadir, the lowest PSA value after radiation. It will not reach zero because it is very likely that you have further mets which are still too small to be detected with a PSMA PET/CT.

[Tall_Allen]

It may take a couple of weeks for pain to subside, and even longer for its PSA to reduce. But your PSA will probably come back. Your metastatic disease is only controlled locally (at the tumor that got the SBRT) for now.

[Claud68]

My husband had SBRT to his cervical met C7, but the SBRT failed completely and the PSA continued to climb. He had 3 Lu-177 treatments after the SBRT and only then the C7 met was less and less aggressive but it didn't disappear completely for now.

[Manilo in reply to Claud68]

Maybe the SBRT was conservative, to not damage the spinal cord.Have you considered doing more SBRT to that C7? Maybe with proton beam? If there is only one visible met, I would try to get rid of it. Just my opinion.

I told my RO to be agressive with my rib met but will not know until next PSMA PET CT F18 scan if it failed or not

[Spyder54]

Yes, McBride at MSKCC says wait 3mos for PSA test after SBRT. Said dying PCa cells put off a lot of PSA leading to false positives. You should see improvement at 3 mos and more improvement at 6 mos. I’m at PSA .04 at 6 mos since SABR/SBRT Jan 20th. Good luck, Mike

[Manilo in reply to Spyder54]

Was that SBRT to prostate? Or to some bone mets?

[Spyder54 in reply to Manilo]

Sorry Manilo, just see now it is Aug 26th. Yes SABR/SBRT was 5 days/treatments to primary Prostate gland (have been reading since about the index lesion and how killing the index lesion, often the largest tumor in prostate, leads to death of surrounding lesions in prostate), and 3 days/treatments to T5 in Spine. Total of 40Gys + 24 Gys = 64 Gys of 8 treatments done over a 10 day stay in NYC. Best, Mike