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Salvage radiation decision: with or without hormone therapy?
Prostate Cancer | Last Active: Jul 30 6:54am | Replies (58)Comment receiving replies
In addition to PSA being so low, that a PSMA PET scan might miss any prostate cancers (as in your case), there are about 15% of prostate cancers that are “PSMA-negative” - they produce no PSMA such that a PSMA PET scan won’t see them, even though you know there’s a problem due to a rising PSA.
In those cases of PSMA-negative prostate cancers, the fallback is to use one of the older types of PET scans that aren’t reliant on PSMA - usually the Axumin PET scan or the C11 Choline PET scan (like Mayo Clinic uses).
If it were me, I’d get the other type of scan first before receiving radiation blindly, not knowing where the recurrence is.
The reason? —> Dr. Kwon (of Mayo Clinic) indicates that only 1/3 of men who have recurrence following prostatectomy have recurrence only in the prostate bed, and that they should not get salvage radiation there unless they’re absolutely certain of the location of recurrence. He says to first confirm where the recurrence is. (See Dr. Kwon’s presentation about recurrence: https://youtu.be/Q2joD360_pI). He talks about this topic specifically starting at about time 3:15 and ending at about time 4:35 of his presentation.
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The FDG scan is a good one to use to find prostate cancer that doesn’t Produce PSMA. The C11 scan is only available at Mayo From what I’ve heard. According to documentation I’ve seen the FDG scan is actually the preferred one to use to detect prostate cancer that doesn’t produce PSMA
There is a question about Doctor Kwon’s Claim, that you shouldn’t have salvage radiation unless you were sure that the cancer is in the prostate bed, it is a tough one, because the cancer frequently can’t be seen for a long period of time. Part of it’s due to the fact that the PSMA pet scan can’t see metastasis smaller than 2.7 mm and in many cases smaller than 5 mm. Yes, between Kwon and the Scholz Discussion about the same issue in the last hour and a half of the PCRI conference in March makes one think they should wait to find out if there are metastasis that can be seen. Scholz was really emphasizing the fact that using SBRT to zap metastasis was working really well for his patients.
I know that for me having salvage radiation did give me 2 1/2 years before my PSA started rising again. Yes, a metastasis did show up way outside prostate bed, But it was at least five years after having the salvage radiation before that happened. When I think about what was mentioned in the March PCRI conference the statement made by one of the doctors “ Seeds for metastasis were already there when surgery was done, waiting to grow.” Sure makes one think that doing salvage radiation may not be a mistake because that could be a place where some future Metastasis could be appearing. It seems that most doctors are still doing savage radiation for most patients that have had recurrence after prostatectomy, It should be interesting to see if this actually changes.