My MO recommends taking PET CT F18 -DCFPYL in case I want to go intermittent after two years of Lupron and Erleada. My PSA is still less than 0.2. I had one PSMA in March 2022 when PSA was rising to 1.03. Scan show 3 preaortic lymph nodes and two spot on ribs. Then 6 weeks RT and ADT (Lupron, Erleada).
My MO reasoning is if scan shows no progression, I can go intermittent.
Should I go for scan or wait till my PSA start rising. I stop ADT for now.
BDW my copay for PSMA is around 2.5K
Thanks for any input.
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Maxi54
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In the EXTEND trial, original imaging was with mostly with bone scan/CT (77%) or some with Axumin PET (23%) and imaging was repeated when PSA measurements increased by 1.0 ng/mL or more.
Retired Radiologist here who interpreted there various Imaging studies (MRI, PET, CT etc) for over 40 years. PSMA PET is not very sensitive for detection of metastatic disease for low PSA values (<0.2).
I have a very experienced MO at Johns Hopkins (heavily involved in research for over 30 years including imaging of prostate cancer). I underwent triple therapy last quarter of 2022 for met to T8 and one positive pelvic node. Micro metastases are surely present not detectable by imaging. Had radiation to T8 and pelvis. PSA rapidly undetectable. Kept on Lupron for one year (last 3 month shot July 2023).
His plan is to continue to follow PSA/T. When (dare I hope if?) my PSA goes above 0.1 he will image with PSMA PET. Rad therapy to any visible disease.
Thank you doc for your input. I had similar PCa progression as you.After my prostatectomy in 8/2013 my PSA start rising after 6 months, also SV involvement and GL 4+3+5.On 6/2014 HT-Lupron and on 8/2014 six weeks RT to prostate bed.8/2017 PSA start rising again quickly and 3/2022 PET Scan: 3 paraaortic LN and 2 spots on ribs.On 4/2022 HT Lupron/Erleada and 8/2022 RT. Till now PSA < 0.02. Now I stopping HT because spine and legs muscles pain.I did Lumbar MRI and I have a lot of arthritis changes and I'm going also to schedule DEXA scan.
You said at the beginning of your response that the PSMA test is not very sensitive for low PSA values (<0.2). But your MO has targeted 0.1 as the point at which to image it again?
That was my understanding from talking to his NP. The sensitivity for low PSA (<0.5) is in the very approximate 50% range although it varies by study. I will refer you to comrhehensive evaluation and discussion in a recent article in 2023 (Application of 18F-PSMA-1007 PET/MR Imaging in Early Biochemical Recurrence of Prostate Cancer: Results of a Prospective Study of 60 Patients with Very Low PSA Levels ≤ 0.5 ng/mL;Cancers (Basel). 2023 Aug; 15(16): 4185.
Published online 2023 Aug 20. doi: 10.3390/cancers15164185)
My decision criteria in conjunction with my medical team was to image when my PSA was between .5-1.0 as it almost doubled the statistical probability of locating the recurrence. For me, that was the right decision.
I also have rapid PSADT and PSAV which may be a factor.
There are a couple questions to consider and ask your medical team:
Will the imaging change the treatment decision assuming it's positive...
Will waiting for the PSA to increase impact the outcome of the treatment decision - say allowing the PCa to spread further such that the treatment is more difficult to get under control or require stronger agents, longer on treatment times...,
Then there's the financial toxicity...especially if pulling the trigger on imaging too early results in a negative scan!
It's a juggling act, waiting for the PSA to rise may give you more time off treatment, increase your statistical of locating any recurrence and informing a treatment decision.
As retired doc says, even if shows location(s) of recurrence there is micro-metastatic disease elsewhere which may require systemic therapy anyway.
Then again, if you are thinking radiation only for MDT and the imaging shows recurrence, then you may have what you need to make your treatment decision, still, micro....
yet, at 0.11, Ga 68 was clear, while 'better imaging' identified five suspicious pelvic nodes. ePLND confirmed six, including common iliac and one para-aortic. Tough decisions with limited information.
I had a PSMA scan last year at 0.3. MO wanted it as a baseline reading and it detected one spinal met for sure and a light shadow of indeterminate origin on upper vertebra. Radiology hit both. Now <0.1. I had previous metastases years ago so metastatic diagnosis is on my record and insurance paid.
Do you have a history of very low or undetectable PSA? That was and is my case, so I get a PSMA scan every three months. They have shown mets even when my PSA was undetectable. That is not the case for most guys with metastatic PC, but there is a subset of us.
My PSA was undetectable after DaVinci surgery in 9/2013 for six months and after that start rising quickly (less than 3 months double). 2014 after HT/RT therapy PSA was < 0.02 till 2017, than start rising reaching 1.07 in 4/2022. Got PSMA scan/ 3 LN and 2 spots on ribs. Again RT and Lupron/Erleada. Till now PSA < 0.02. On my last visit I ask my MO to go intermittent HT. He's advice was to do PSMA again. I think at PSA < 0.02 that's too early.
My decision if/when to have imaging is not based on population 'success' data nor rising PSA from X to Y, but rather, on my intent to not give this beast time and obscurity. My perspective is that if I am lucky enough for targets to show, then I can develop a strategy other than waiting.
My annual blood biopsy testing happens to be next week, and if this remains unchanged, and as my PSA continues holding very low stable, I am thinking to take a pass on upcoming annual imaging.
I am considering alternating imaging methods as success at very low PSA levels seems to have an arbitrary component. (This may take some doctor shopping as it seems there can be economic/contractual considerations for methods docs want to use).
My personal experience reference point is the imaging result I share about, the Ferrotran nanoparticle MRI I had over six years ago. While the comparative Ga 68 was 'clear', the nanoMRI identified five suspicious pelvic nodes which were successfully treated. That experience and outcome taught me imaging can be successful at 0.11, and also, to not think 'clear' imaging indicates all is well.
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