My Post- RP (August 2018) PSA level has doubled from 0.09 in June '23 to 0.19 in June '24, and doubled again to 0.40 in December 2024. A visit with a radiation oncologist at Moffitt Cancer Center on December 16 confirmed I should have a PSMA/PET scan soon.
My local oncologist, who has cared for me since May 2018, wants to wait another three months before ordering a PSMA/PET scan. My Post-RP PSA has had several 6-month and 12-month episodes of dropping significantly after a big increase. The Doc wants to wait until mid-March to confirm the PSA is increasing. I 'sorta agree with him.
The Moffitt Cancer Center radiation oncologist I saw on December 16 wants to get the scan done ASAP. I asked him why the rush since the PSMA/PET scan sensitivity at PSA levels below 0.5 is only 52%. My questions was:
- if the scan is negative - we know nothing because 50% of the time PCa would not show up
- if the scan is positive - the PCa has already started growing and another couple months will not change anything
- my Decipher genetics evaluation (from the excised tumor in August 2018) show only about a 5% change of metastasis in 10-years (August 2028) so I feel there is little risk of waiting at this point
- if the scan is negative and we plan RT based on that result and a subsequent scan shows PCa outside the area to be irradiated - then I have to do another round of radiation - so why not just wait a few more months to have a better "image" of the problem
The Moffitt guy had no clear answer to my questions - just said that we should do the RT now and if necessary hit the newly found PCa (in the pelvis or distant mets) as they are discovered.
My thought at this time is to wait until early February (two months after my last PSA test) and get the test. If it comes back greater than 0.60 then go ahead with the PSMA/PET scan.
I know I need the RT - but there is a lot of research that says delaying from time when PSA is 0.5 to 2.0 does not seem to increase the risk of future distant mets, PCa death, and does increase OverAll survival in older men (currently well past 77).
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OldTiredSailor
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'but there is a lot of research that says delaying from time when PSA is 0.5 to 2.0 does not seem to increase the risk of future distant mets,..." May I see any of that research?
Wishful Thinking and Mis-remembrance on my part. Here is an excerpt from what I consider from the best current summary:
While the pre-SRT PSA level is known to be a significant predictor of post-SRT disease progression, the optimal timing of SRT is still controversial. Although there is a lack of randomized controlled data, several retrospective studies have shown that PCa patients with a pre-SRT PSA level ≤0.5 ng/mL were more likely to have better oncologic outcomes than those with a pre-SRT PSA level >0.5 ng/mL.
In addition, King et al revealed that BCR-free survival decreased by up to 4% with every 0.1 ng/mL increase in the pre-SRT PSA. They reported that waiting to initiate SRT until the PSA reaches 0.6 ng/mL would result in a 20% reduction in the BCR-free survival, when compared with performing SRT when the patient has PSA of 0.1 ng/mL.
However, the potential benefit of SRT must be balanced against the possible detrimental effect on functional outcomes, specifically, urinary continence and erectile function. In addition, some patients with what is destined to be indolent BCR will be overtreated with early SRT. In the present study, patients with pre-SRT PSA >0.44 ng/mL were more likely to experience disease progression. Therefore, we propose that SRT should be performed before the patient has a PSA level of 0.44 ng/mL, which is close to the timing recommended by current guidelines.
Regarding "PSA level ≤0.5 ng/mL were more likely to have better oncologic outcomes than those with a pre-SRT PSA level >0.5 ng/mL". Based on my learnings it is not about the PSA value nor the timing, but rather, where is all the cancer at the time of treatment?
Turned out for me, at 0.11, my cancer was already out of the bed and as far as the para-aortic (typically not within rad field I have been told). So, in my case, "guidelines", timing of salvage RT, and whether to bed or pelvic region, did not matter.
my understanding as a non doctor is that RT is more effective if done below 0.2 psa. This sometimes means doing it blind if the psma pet doesn’t show anything but that is better than doing it at psa greater than 0.5. In other words, the sooner the better and if the psma helps to target things so much the better and if it doesn’t, at least you tried.
Contrary to so much, eight years ago I learned imaging in Europe begins as soon as 0.03 post RP. After my unsuccessful salvage RT to prostate bed, imaging at 0.13 identified multiple suspicious pelvic lymph nodes. Salvage ePLND confirmed six cancerous nodes including para-aortic.
I have learned many things with four treatments over these past ten years (Dx week before Christmas 2014), including not giving this beast time and obscurity. All the best!
"- if the scan is negative - we know nothing because 50% of the time PCa would not show up"
Exactly.
You are the consumer. Why would you want such a large likely of a false negative? Unless you plan to do it twice.
TA has some statistics on his pca website. They show that to get the most accurate results from most of not all these scans you need to wait until you reach a 2.0 PSA.
Almost all these treatments take a lot out of you and your body. Who wants to risk a false positive. And a false negative is even worse.
Either way you are the one who pays for the misstep.
I had SRT following RP three years following the surgery in 2019. I have had PSMA-PET scans at six month intervals with a slowly increasing PSA to 2.74 presently. My next PSMA-PET is in January. The PCa is growing someplace and I and my MO at DF are of the opinion that checking every six months with the scan and then moving back to targeted tumor directed treatments is logical. I plan to travel back to UPenn for PBRT. One cannot shoot what one cannot see. I believe your logic is sound.
I put this conversation into AI and here is the result:
Your approach seems thoughtful and balanced, given the circumstances and the challenges of interpreting PSA kinetics post-radical prostatectomy. The timing of a PSMA PET/CT scan depends on several factors, including PSA level, doubling time, and the therapeutic goals (e.g., whether to start salvage therapy).
Considerations for Timing PSMA PET/CT:
1. Sensitivity at PSA Levels:
PSMA PET/CT is typically more sensitive at higher PSA levels:
>0.2 to 0.5: Sensitivity is around 50-60%.
>0.5 to 1.0: Sensitivity improves to 70-80%.
>2.0: Sensitivity exceeds 90%.
However, imaging at lower PSA levels may still guide early salvage therapy, particularly if the PSA doubling time is rapid (<6-12 months).
2. Clinical Guidelines:
Some European centers recommend early imaging at PSA ≥0.2, especially if PSA doubling time suggests aggressive disease.
U.S. centers often use a threshold of 0.4-0.5 to improve diagnostic yield.
3. Treatment Timing:
Salvage radiation therapy (SRT) is most effective when initiated at PSA <0.5, but imaging results at lower PSA levels may still influence the radiation field (e.g., prostate bed vs. lymph nodes).
4. Risk of Progression:
Your Decipher genomic score (5% risk of metastasis in 10 years) suggests relatively indolent disease, which supports a cautious, evidence-based approach rather than rushing into SRT without clear targets.
Your Plan:
Waiting until February for a PSA level check and considering a PSMA PET/CT if the PSA exceeds 0.6 is a sound compromise:
It minimizes the risk of false negatives while not delaying action excessively.
If the PSA continues to rise rapidly, imaging at that point will likely provide clearer guidance.
Points to Clarify with Your Oncologists:
Doubling Time: A key indicator of aggressiveness and timing for salvage therapy.
Radiation Planning: Would SRT to the prostate bed be initiated regardless of imaging findings, or will the PSMA PET/CT determine the radiation field?
Ultimately, this decision aligns with your personal preference to avoid unnecessary treatments while ensuring timely intervention. Balancing input from both oncologists, as well as the data on PSMA PET/CT sensitivity, should guide your final choice.
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Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.
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