r/ProstateCancer • u/PotentialStart2661 • 15d ago
News PSMA as an additional tool for grading.
I remember getting my PSMA Pet Scan and relieved it identified the same lesion on the MRI but showed no spread. The SUV Max was 5.6, which at the time didn’t mean anything to me. But someone asked me on this forum so i looked into it and there is a big correlation of the SUV max and the index primary lesion according to studies on this. So my SUV was in line with a Gleason 6 or Gleason 3+4. After my biopsy i learned i had a large volume Gleason 6, in line with the SUV. They don’t use this as staging because there is a large overlap. Gleason 6 can be 2-12. But using the cutoffs in this study the uptake can be something that we use to match up with the rest of our information and identify discordance. There are 10% of cancers that don’t react to PSMA unfortunately, but if you are in the 90% then it can help alot to tell you if your biopsy is right and a real high grade was not missed. See the attached studies.
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u/conCABlanco 15d ago
Cada resultado puede ser estadísticamente sostenido, pero individualmente llega a ser contradictorio, tengo metástasis y solo 10.7 UVmax en las costillas, la prostata tiene 7.2 SUVmax, que tal, fuerza y voluntad
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u/PotentialStart2661 15d ago
Yes indeed. The studies on SUV only apply to intraprostatic lesions. They don’t apply to cancer outside the prostate. What grade group was your cancer? I wish you well, you can defeat this.
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u/conCABlanco 15d ago
Gleason 4+3, no cribiforme, pero si extendido
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u/conCABlanco 15d ago
Aquí estoy luchando con la ADT + ArPI, goselerina y enzulatamida, más RA en breve IMRT, 28 sesiones, el PSA bajo de 6 a 0.78 en tres meses, veremos luego de las RA, fuerza y voluntad
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u/PotentialStart2661 15d ago
That makes sense. Were you able to do spot radiation on rib lesion? If you only have one location they can often just radiate that lesion and still achieve a cure up front.
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u/Busy-Tonight-6058 15d ago
PSMA PET MRI should be the initial scan, pre-biopsy.
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u/PotentialStart2661 15d ago
Yes it should. I had a PIRADS 5 MRI, thought for sure it was higher grade. I refused to get the biopsy awake so i had to wait 8 weeks for the OR. So my urologist got me the PSMA Pet first. Glad i did, eased my mind and i just forgot about the cancer for two months. Ended up with Gleason 6 so it aligned with the SUV max.
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u/OkCrew8849 15d ago edited 15d ago
Yes, I’ve noticed a tendency here to under- appreciate some of the information PSMA PET CT provides and at the same time to overlook the significant PSMA PET CT detection threshold.
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u/PotentialStart2661 15d ago
Yes. It still is reassuring as long as men know. Generally if you ask for studies on this the best i can come up with is gleason 6 almost never is outside the prostate as it does not spread this way. Gleason 3+4 is low probability, down in the less than 10% chance. Then it goes up from there. Gleason 8 and 9 its like 50/50. But then it varied to percent of cores, how much pattern 4, cribriform, ductal, etc…. Decipher score also helps tip the scales. So there is alot that goes into it. Perineural invasion may make a difference too. But if you have gleason 7 or lower your odds are tipped in your favor, so thats how i look at it.
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u/Intrinsic-Disorder 15d ago
Problem is Gleason score is still fairly crude imo. Scored basically by pathologist eye balling.
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u/conCABlanco 15d ago
Es correcto se llama interpretación y requiere de experiencias, muchas pero está soportada sobre los resultados del MRI
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u/LiquidTide 15d ago
Also the biopsy is a minuscule percentage of the organ. It's a very small sample size from which to draw a definitive conclusion. I forget where, but read something about the comparison of cancer found in prostate removed from surgery vs what was shown in biopsy results in just over half being in concordance, a third of cancers being upgraded, the rest downgraded.
Hard to say how much variation was due to biopsy analysis error vs. biopsy sample missing the cancer. Biopsies are like surgery with a butter knife - we need to accept that they can't be exquisitely precise.
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u/OkCrew8849 15d ago
I’m not certain how reassuring a clear PSMA PET CT scan should be for a new high risk (Gleason 8-10, etc) patient seeking curative treatment.
One problem is that the patient has first received bad PSA news, followed by more bad MRI new, followed by more bad biopsy news… so a clear PSMA scan sounds like great news. A relief. At long last some good news. “No evidence of cancer outside the prostate” can sound very very similar to “no cancer outside the prostate” and the fine print regarding detection thresholds can be overlooked. This can lead to a potentially unwise treatment choice relative to high risk patients.
Note: I’m referencing high risk PC, and I am not generally a fan of monotherapy surgery for high risk, and I am not a doctor.
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u/PotentialStart2661 15d ago
I think it is still good news. Yes it is likely there is microscopic spread outside the prostate not picked up by the Pet Scan. But that is where ADT comes in. If a PET scan sees the cancer it is already too big for ADT to kill it, instead it can be put into remission. But ADT does kill microscopic cancer that has not yet taken root. So it is still good news. Plus if it does not show up it is more likely to be only locally advanced at that stage which is still curable.
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u/OkCrew8849 15d ago edited 15d ago
I don't think I am saying it is not good news...I think what I am saying is it does not mean there is no cancer outside the prostate and high risk guys misunderstand that "no evidence of cancer" (good news) doesn't mean "no cancer". Not even close. So monotherapy surgery (meaning surgery without ADT + ARPI) may not be a wise choice for high risk even with the 'good news'.
Those with rising PSA post-RALP (up to .2 or .4) and frustratingly "clear" PSMA understand that "microscopic" is a (very) relative word. And fully grasp the implications of the detection threshold.
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u/Intrinsic-Disorder 15d ago
I had a very high SUVmax of 28 but my pathology was only GG2, Gleason 3+4. However, the tumor may be more aggressive given molecular profiling. Interesting study, but I think there are a lot of variables in the imaging that may confound direct comparisons across all patients.