LU 177 now or later?

[kiskadog]

I had a prostectomy by robotic surgery 7 years ago. It was Gleason 9 and had a little outside the capsule, but my surgeon thought he got it all, so sent me home to have PSA'a 4 x per year. The highest my PSA had been was 8.8 before surgery.

In 2018, my PSA started to climb to about 0.6, so I was sent for a PET scan, which was negative.

I contacted my surgeon at UCSF, who suggested a GA68 PSMI scan. In November 2017, that showed about 6 mets in my abdomen near the descending aorta, deemed inoperable and diagnosed as stage 4M1A . In addition there was some tumor in the area where my prostrate had been, and my PSA was up to 0.86.

I did a month of Casodex, then Lupron with Zytiga and Prednisone. My Testosterone and PSA have dropped to T>10 and PSA > 0.1 in every monthly test since.

I had no physical symptoms, but the ADT has hit me hard with hot flashes. I wake every 45 min to sometimes an hour, so get no quality sleep which is leaving me miserable.

I am 69+ but still very busy and working 7- 8 hours 7 days per week as I am self employed. I've been doing exercise classes 3 days / week to keep my muscles and bones healthy, and mostly vegetarian diet with low sugar and no alcohol.

I found out about the 177LU PSMA treatment and contacted Bad Berka, and others. The others rejected me because I am not castrate resistant, but Bad Berka said they would give me the treatment.

My question for the many of you who are so knowledgeable about PSMA treatment is; Have I shot myself in the foot with my present treatment that has suppressed the PSA so that the ligand that carries the LU177 may not now find the mets, since they are now suppressed? Should I stop the ADT to allow the mets to began producing PSA so they can be found? I'd sure like to stop ADT as it screws my sleep up so bad. Should I get the treatment ASAP or wait. I was hoping to knock the mets down before they got worse and or castrate resistant. Getting this radiation now may reduce how much I can get later if they become resistant.

I live in rural Alaska, so travel is difficult and expensive. I don't want to waste time or resources that I may need later.

Your thoughts would be greatly appreciated.

[Tall_Allen]

Someone in my Group just had his para-aortic LNs irradiated in an attempt at curative salvage therapy after the rest of the pelvic LNs and prostate had already been done. He is taking Zytiga+Lupron for 2-3 years also. In your case, you would need prostate bed radiation as well. You would have to talk to a radiation oncologist, not a surgeon.

Some studies show that PSMA avidity increases with ADT, others do not. Either way, it is certainly a terrible idea to stop your therapy in order to find more metastases - that is a self-fulfilling prophecy. At any rate - what's the difference? Lu-177-PSMA-617 is taken systemically and you already know you have PSMA-avid metastases.

[tango65]

My experience is that they will not treat with Lu 177 PSMA if a Ga 68 PSMA is negative. They only treat disease that can be seen.

With a PSA of 0.1 most probable the Ga68 PSMA PET/CT will be negative. I am in a similar situation. I am allowing the PSA to go up and getting PSMA PET/CT scans. Last PSMA PET/CT with a PSA around 0.4 was negative.

[GP24]

".. the ligand that carries the LU177.." does not depend on the PSA but on the PSMA expression. If you start with ADT, the PSA value will go down but it takes longer for the PSMA expression to get lower. See this study:

ncbi.nlm.nih.gov/pmc/articl...

However, after one year of ADT the PSMA expression is reduced so this will not be an ideal situation for a Lu177 therapy.

Either you switch to intermittent ADT to get the PSA value and PSMA expression up for a while or you should wait until castration resistance develops.

[monte1111]

Gabapentin really helped with my hot flashes. Just started taking B-12 and B-Complex, for mild anemia about a week ago and having deeper sleep, I will see if that continues. I'm from up 7x to 3x with last stretch pretty satisfying. Just some thoughts, I'm not a drug pusher.