Drop in PSA after SBRT

[Scootman]

I posted this reply earlier:Completed the sbrt 4 weeks ago and as you said took the 4 weeks for things to start to feel better. Had a PSA done this week and my PSA has been climbing for last year. I am on Zytiga and prednisone for about 2 months. My last PSA in August had gone up to 62.9 was told because of the mets in pelvis. reading today is 56.2 . A drop but hoping for a larger drop. I am assuming this drop was from the sbrt not the Zytiga . Not that I am not thankful it did not go up but was hoping for a more significant drop. Am I assuming correctly. Thanks. I had a thought after posting and wanted an opinion as to whether I was thinking incorrectly. My PSA has been going up at least 10 to 20 point recently. So if this latest reading came down by just 7 points is it possible that it actually came down much more since I was increasing each test and this reading would be more of a drop than 7 points because it probably would have gone up with out the sbrt and possibly the Zytiga. Am I just trying to be hopeful or does that make sense?

[GP24]

Here is a trial using SBRT for oligometastatic CRPC patients. I do not think it is a well-designed trial, more a group of case studies, but maybe it is interesting for you:

euoncology.europeanurology....

[treedown]

Being hopeful is good. I hope somebody can answer you but it seems like a lot of unknowns and 4 weeks or 2 months is not a lot of time to see results IMO assuming I read your post correctly. Best of luck in where your treatments get you.

[Scootman in reply to treedown]

Thank you

[Tall_Allen]

Always a good idea to confirm the lack of effectiveness with a bone scan/CT and to give the Zytiga a little longer to kick in. Weren't you going to look into combining Xofigo and docetaxel?

ejcancer.com/article/S0959-...

[Scootman in reply to Tall_Allen]

there was no talk of starting the Xofigo and docetaxel yet. I was on Xtandi for 3 months and did not have any effect . Was told it was 20% chance Zytiga would work but you think it has not been long enough yet?

[Tall_Allen in reply to Scootman]

There is talk if you talk about it.

[SPEEDYX]

Zytiga took 5 months to kick in for me

[Scootman in reply to SPEEDYX]

Thank you

[Ausi]

My PSA levels dropped from 16 to only 9 after 6 weeks following the end of radiation (IMRT) in Dec last year. I’m on ADT (Zoladex) only. But the PSA dropped further to 5 and then to 2 and stayed there but. It’s now increased to 6. I’m wanting to see if I can do it again! I’ve still to arrange PET scans and RO appointment.

All the best