? Should I stop casodex prior to PSMA Pet scan for better detection rate.

[jjpeabody]

I am anticipating having PSMA Pet scan at UCLA in March. At 22 months post RP PSA has risen to .19 with a PSADT of <=3 mths. Per urologists, started casodex 50 mg 1x. After 23 days on casodex my PSA went to .14 from .19. I am considering stopping casodex for 2 months in the belief that the scan may provide better detection. My Gleason was 4+3=7, extra-capsular ext with negative margins; positive perineal invasion; lymph nodes and vesicles neg. PT3aNO. Longevity conservatively 10 years; incontinence 1-2 pads after 2 years. Leaning toward ADT vs ADT/SRT. Also, anyone have any experience with Dr. Kresl, Cyberknife Phoenix Az. Still considering SRT IMRT with him or Dr. Wong at Mayo. Thanks for any thoughts! I need to decide ADT or SRT soon. I really would like to bring in PSMA Pet into decision. Thanks as always.

[Tall_Allen]

Since the Casodex doesn't seem to be doing anything for you anyway, why not stop it? There is an interesting phenomenon that occurs when starting ADT - PSMA expression can actually increase for a couple of months, before it decreases.

But why bother with a PSMA PET scan at all? At a PSA of 0.19, adjuvant ADT doesn't improve results and SRT is obviously a good idea. The PET scan isn't likely to change that.

[jjpeabody in reply to Tall_Allen]

Thanks for your timely reply and input. Getting all the info I can to make an informed decision can be like pulling teeth. I'm 70 and despite actuarial tables etc I feel I have 10 good years longevity. The two radiologist I mentioned say they "believe" cancer is limited to the bed. Dr. Sholz from PCRI suggests including the pelvic area would add little additional side effects and that sounds reasonable to me. Have been moderately incontinent since surgery, 1-2 pads, and would not like to spend rest of life at 2 or more pads. I have yet to understand if a hormone treatment plan would offer similar longevity and acceptable side effects, not to mention potential new tech like LU-PSMA-617 etc, vs SRT longevity and side effects. I assumed PSMA Pet scan might show up something outside bed to aid in treatment decision. Note, PSADT confirmed by urologist and reason to start ADT is <=3 mths. Also keating namogram for SRT with ADT for my situation is about 56% vs 36% without ADT. Thanks for your input in helping my decision process. It sounds like you favor SRT without hesitation?

[Tall_Allen in reply to jjpeabody]

I'm unfamiliar with the keating nomogram, but analysis of clinical trial data showed that men given SRT did not benefit from ADT if their PSA< 0.7

europeanurology.com/article...

Perhaps you have other risk factors that make ADT advisable?

Your concerns about incontinence are justified. Salvage radiation will possibly make a bad situation worse. If so, perhaps an artificial urinary sphincter.

Did you fill out this nomogram for expected longevity?

webcore.mskcc.org/survey/su...

[jjpeabody in reply to Tall_Allen]

Tall_Allan, yes the correct SRT namogram was from mskcc.org instead of "keating" as I wrongly quoted and showed an improved significant outcome with ADT included with SRT. I took the longevity nomogram and it came out with 46% surival after 10 years. I will still pursue PSMA Pet scan with UCLA. I guess there are no "best" answers in my situation and no guarantees. Any thoughts what ADT treatment plan might look like and conservative longevity, or is that an unrealistic question with too many unknowns. I started following you today as you cover a wide range of important topics. Thanks for your input, Jim

[Tall_Allen in reply to jjpeabody]

If you are pursuing SRT, Spratt's protocol is better info than a nomogram.

If you want to use ADT without SRT, adding Zytiga for even a limited term may be ideal:

meetinglibrary.asco.org/rec...

[Justfor_]

Similar cases. My plan is one month Casodex before PSMA PET CT in the hope it temporarily increases PSMA expression, If all lutamides can cause such an effect it would be useful not to stop now but bring the scan earlier, if possible. Also, your PSADT of 3 months or less is not consistent with your rest history, ie 22 months after RP and 0.19 PSA. You are probably deriving it out of a limited number of late time samples. A substantial margin of error can be introduced in such a case. If you gave me your time-series I could offer you my best estimate.

[jjpeabody in reply to Justfor_]

Very good Justfor, thank you. If you click on that "ball" where a picture should be next to my user id, it should open up my profile, let me know if you can't please and I will type PSA history. Your assumption re PSDAT has merit. My RP was on 2/14/19 and psa was basically .009 for first 8 months then went to .041 on 2/12/20. On 7/9/20 was .085; 10/9/20 .124; 11/13/20 jumped to .19 which raised additional concern. 12/22/20 after 23 days on Casodex was .14. I have been on casodex since 11/29/20 and will likely be scheduled for scan by second week of March or a little sooner but not February. Wondering if casodex will still be helpful by then or stop now. Let me know what you think and you might see my reply to Tall_Allen. Thanks for your reply, very helpful, I feel I'm getting closer in decision process with the boards input. Jim

[Justfor_ in reply to jjpeabody]

I saw that I ran your numbers 3 months ago. There is only one additional sample to add, that of November 2020. The latest one, under Casodex, is not eligible. One clarification needed though: All your prior values were to the 3rd decimal point. Nov. 0.19 is to 2 decimal points. Does this mean that it came out as a round number, or you used another lab?

This 0.19 from November, if coming from the same lab, is a game changer. In my previous analysis your linear - exponential curve fitting regression coefficients were in favour of the former. Adding the 0.19 swipes the whole curve to the hyper- exponential territory. If this 0.19 was accurate you did well to embark to Casodex.

Regression coefficients 3 months ago: Lin = 99.5%, Log = 96.6%

Regression coefficients now : Lin = 92.9%, Log = 98.0%

My (Log) estimate regarding PSADT is 3.3 months.

[jjpeabody in reply to Justfor_]

I moved to AZ early November from Oregon. In Oregon I used Quest Diagnostics and in AZ Sonora Quest laboratories. So it is true there is a difference in labs, however I believe a near 50% increase in one month would not account for that completely. An additional test with Sonora is warranted. But if you plug in the numbers into Keating monogram for salvage the numbers are better with ADT. Also, I am considering ADT alone as a treatment plan as indicated to Tall_Allen, so when urologist suggested ADT before SRT I agreed. When I run nanograms with 6 mth PSADT instead of 3mth I get 66% with ADT and 43% without as opposed to 56%/36% for 3mth. I still like using PSMA Pet scan before deciding treatment. And I like using ADT with SRT if I choose SRT. I believe my PSA without casodex would be over .2 by now. If I continue on casodex it will be 3 mths by PSMA scan. I wonder if it's effect on the scan would be positive or negative. Please let me know what you think, I appreciate your thoughts on any of this. Jim

[Justfor_ in reply to jjpeabody]

My latest personal experience showed a 28% diff, between 3 labs 5-6 days apart.

PSMA PET/CT is a MUST for me. Only old school or silly doctors would argue against.

Two papers I have read on the subject (one is a very recent meta-analysis) claim that in our low PSA category of less than 0.5 PSA, PSMA pet detection have stratified the ascending PSA to be divided among 20-25% to distant bone or visceral metastases, the remainder 75-80% split almost in half between lymph nodes and prostate bed. Taking into account that lymph nodes can be local or distant, these numbers are in good agreement with the quoted success rate of sRT, spanning from 40-60%. This also supports the claim for a better outcome when local lymph nodes are also irradiated.

Regarding the timing of the purported PSMA peak stimulated by lutamides (only properly clinically tested with enza) I have read all sort of speculative numbers. Min being 2 weeks, 1-3 months frequently coming into mention, 6 months or longer are absent. Take your pick.

Relevant reading:

researchgate.net/publicatio...

Specifically check Figure 1B of this:

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

A literature review:

link.springer.com/article/1...

[jjpeabody in reply to Justfor_]

Justfor, thank you for your reply, links and analysis, it was helpful in my decision making. I plan to stay on casodex for now and seek PSMA scan.

[JPnSD]

Wishing you all the best. I have a similar profile...but GL9 I am on Degarelix (Firmagon) injections since Oct....but just filed for Orgovyx (oral)...PSA Undetectable since started ADT...but awaiting Salvage IMRT after I get the vaccine. At 67...trying to get as much longevity as possible. Let me know how your PSMA goes...it is on my radar for the future. Putting my money into Orgovyx at $7200/yr for the time being...as I can't stand 3-5 days of pain and swelling after the monthly Firmagon injections.

[jjpeabody in reply to JPnSD]

Thanks for your reply JPnSD, I just happened to start following you this morning. You have a good attitude, work ethic and of course wish you the entire best. Have you heard of Dr. Mark Sholz with Prostate Cancer Research Institute (PCRI), I follow their videos while watching TV on YouTube. You seem to be following a good plan and I will be following your informative posts. You might run your treatment by Dr. Sholz, but I know you are very thorough and diligent already. One thing I heard Dr. Sholz say recently is how some patients have gotten these expensive medications for free by having their doctors (he has done it) file some kind of "hardship" request to the manufacture, it almost sounded like hardly anyone is ever turned down. I never heard of that before. Good luck and thank you, Jim

[JPnSD in reply to jjpeabody]

Thanks Jim. Yes, I am aware of PCRI and the doctors there and have followed their videos. I have done consultations with all available doctors at Sharp with PC expertise here in San Diego as well as 2nd opinions with the fine team of doctors at UCSD who focus on PC. People on here like Tall Allen and many others have been an invaluable source of information....and support. I wish all of us respite from the APC journey...and many days of peaceful contented living.

PS Myovant is giving 2 months free of Orgovyx as a starter at the moment.