What is the best treatment sequence?

[Simonapo]

Few months ago, my Dad’s PSMA Pet showed small L2 and T8 Mets. We decided to do Provenge and after that SBRT to the Mets with Dr Kishan at UCLA. The MRI right before the radiation showed a lot more than the PSMA Pet did : “Significantly progressed multifocal marrow replacing vertebral lesions throughout the L1-L4 vertebrae including the right L2 and L3 posterior elements with additional likely smaller foci at other levels. New L5 superior endplate marrow replacing lesion. Again seen diffusely increased T1 marrow signal from the L5 to lower sacral levels, likely reflecting post radiation change. New scattered T1 hypointense in the L5, S1, left sacral ala and visualized bilateral iliac bones, also likely reflect additional metastatic foci.” I am beyond terrified, are all these Mets or just some of them? How is it possible that it didn’t show up on the PSMA Pet 2-3 months ago? How could be so many with a PSA of 0.03? What would be the most effective treatment sequence? He had radiation at the time of Diagnosis back in 2021 and has been on Abiraterone and Prednisone ever since. He also had Provenge 2 months ago and SBRT now. It is clear that Abiraterone doesn’t work anymore. Should we try to replace Prednisone with Dexamethasone? Switch to Xtandi? Or chemo? Anybody else had these kind of MRI readings and can explain what all are? Any help and suggestions are greatly appreciated. Thank you so much.

[Tall_Allen]

"How is it possible that it didn’t show up on the PSMA Pet 2-3 months ago? " Not all metastases are PSMA-avid.

"How could be so many with a PSA of 0.03? " Not all metastases express PSA either.

"What would be the most effective treatment sequence?" See a medical oncologist. Discuss a biopsy of some of those metastases with histology, IHC and genomics.

[Simonapo in reply to Tall_Allen]

Thank you so much Allen, I appreciate your great advice.

[Warriorthree]

Been on Xtandi for over 4 years now if covid hadn’t been about I would have had Chemo take four tablets a day my Psa was 2600 after taking tablets went down to 0.02 and has remained there feel so lucky

[Professorgary in reply to Warriorthree]

God bless! That is great!

[Warriorthree]

Thank you so much my friend I hope everything works for you we are all in this together as brothers

[NecessarilySo]

Could be mets from some other kind of cancer which would explain low PSA, e.g. multiple myeloma or bone cancer, whatever.

[Simonapo in reply to NecessarilySo]

So frightening but true, thank you for pointing that out.