Conflicting MRI vs PSMA scans

[icanwintwice]

Well it appears that the radiologist who did my MRI was overly cautious. The report said I had a met on my left pelvis, one on my right pelvis, one on my sacrum, additional cancer in my prostate region and sclerotic foci in my pelvic region. Traumatic.

We followed that up with a PSMA scan 10 days later. A scary 10 days. The PSMA scan said that I had no cancer in my body. I have since also learned that the sclerotic foci is usually a benign bone lesion on the pelvis. Great news I think???

My PSA is undetectable. My testosterone is 8. I am currently on Lupron and Erleada for six more months. Ive been on both for 18 months now after radiation to the one cancerous lymph node, below the illiac artery, and my entire lower lymphatic area.

My questions to my good friends on this blog is this..

Can the PSMA scan have missed something? It seems to good to be true even though the hospital that did the MRI also did the PSMA and called me and said I was cancer free???

Also, are there any other scans that might be out there to double check to make sure the PSMA was correct. I was planning on doing four doses of chemo (docetaxel) on the back end of my treatment.....is this still an option if I am cancer free?

this blog has been great for me ......thoughts?

[Tall_Allen]

There is no reason to do docetaxel if you don't have bone metastases. There are no scans that will show anything at your PSA.

[Hidden in reply to Tall_Allen]

What you read in publications, and real-life are two different things.

I have undetectable PSA, and my last PSMA still detected uptake in one lymph node.

Granted it was "slight" 5 mm with 2.3 MAX SUV. It was detected.

[Tall_Allen in reply to Hidden]

SUVmax=2.3 may not be above background and may be a false positive.

[Hidden in reply to Tall_Allen]

Same lymph node been observing for past year. MAX SUV 24 last year. It’s shrinking.

[Tall_Allen in reply to Hidden]

If it shrinks with radiation+ADT, it was certainly positive, and you treated it per your profile. I don't understand your comment, then.

[Hidden in reply to Tall_Allen]

My comment was that with undetectable PSA a PSMA scan still detects.

In response your comment above.

[Tall_Allen in reply to Hidden]

But it is probably detecting zombie cells in your case.

[Hidden in reply to Tall_Allen]

Haha

Please explain zombie. Never hear that.

[Tall_Allen in reply to Hidden]

Radiation kills some cancer cells immediately. For others, it inserts reactive oxygen species (ROS), mainly hydroxyl radicals, into the DNA, causing it to break. Those cells may stay alive until they try to replicate, and die then (called "mitotic catastrophe"). But the cells may become dormant for a while, avoiding mitosis. I call them "zombie cells"- they are dead, but don't know it yet. Sometimes it can take years to finally give up the ghost. Meanwhile, they may show up on non-metabolic imaging (e.g., MRI or PSMA PET).

[Hidden in reply to Tall_Allen]

Ok

That was the question I asked my RO.

If they are dormant via ADT will they ever die? Since mitosis won’t happen.

[Tall_Allen in reply to Hidden]

Eventually, the cells will try mitosis. It's what cells do. But it doesn't really matter, since they are benign anyway. It took 3 ½ years for mine to finally disappear. PSA is a better guide, since zombie cells are incapable of forming the blood vessels that are necessary for PSA to enter serum.

[Hidden in reply to Tall_Allen]

Makes perfect sense. Thx

[Papa1 in reply to Tall_Allen]

The breadth and depth of your knowledge is just staggering.

[Jmr11820 in reply to Tall_Allen]

Can one have metastatic disease with an undetectable PSA? I thought not.

[icanwintwice in reply to Jmr11820]

Thats a question for Tall Allen….but id sure like to know!

[Tall_Allen in reply to Jmr11820]

Yes, of course. We have some really great medicines like ADT, second-generation hormone therapies, docetaxel, and cabazitaxel, that get many men to undetectable PSA after distant metastases have been detected. Some very virulent anaplastic types of PCa never express PSA. It is also possible to treat PSA without treating the underlying PCa:

prostatecancer.news/2020/07...

[Jmr11820 in reply to Tall_Allen]

I understand. For those of us who opted for surgery and continue to monitor PSA for recurrence, in that situation the PSA would move in the event that you had metastases, isn’t that right? Asking for a friend 😊.

[Tall_Allen in reply to Jmr11820]

Almost always. Biochemical recurrence (PSA>0.2) is the first clue that there may be metastases, and clinical recurrence is suspected.

[GP24]

You could get a second opinion on the MRI scan.

[Pharm1125]

Hi,

If you have been on ADT for many months prior to both the MRI and PSMA, wouldn’t it be logical that the PSMA would be clear as the drugs usually drop PSA to undetectable levels?

[Kittenlover50]

They say the PSA needs to be at a .4 or .5 for increased reliability with a PSMABills PSA has inched to .22 and doc wants to wait until .4. His c11 choline showed activity last year but was around an old break in back and had been lifting a lot of heavy furniture. Two MRIs were neg. The next c11 was neg too.

[sillyoyster]

Psma is the gold standard for prostate cancer detection. You may want to ask for a axumen pet scan. The forerunner to psma.

[NotDFL in reply to sillyoyster]

I think that's oversimplified. Both scans have their pros and cons and detect different abnormalities.

[j-o-h-n]

Me..... who hates to be a fly in the ointment.................says a Pca cure is like saying the NY Giants will win the Superbowl.

Good Luck, Good Health and Good Humor.

j-o-h-n Saturday 10/14/2023 12:26 PM DST

[Bowmaster]

Too many scans in such short time is no good for you ! Way too much radiation for your body .

[StayingOptimistic in reply to Bowmaster]

Can you do these psma every 6 months or still no good in terms of radiation?

[Bowmaster in reply to StayingOptimistic]

I have been told more then once that SCANS should be done once a year and no more ! This way the body can recover somewhat . I was also told that too much radiation weakens the immune sistem .

[gsun]

What about an FDG PET scan for the cancer that does not express PSMA?

[slpdvmmd]

I am not a radiologist but have looked at a lot of advanced imaging during the course of my training and career. First thing you learn is that what looks like nothing with one form of imaging can look absolutely catastrophic on another. I distinctly remember training during the hay day of AIDS as it was called then and seeing a patient with distinct neurologic findings with minimal changes on a brain CT that seemed not to explain my clinical findings. Then an astute neurosurgeon (I was on his service at the time) told me to order an MRI which I did. The brain on MRI looked like Swiss cheese. Different modalities of imaging have differing strengths and weaknesses and may or may not show differenent things.

With regard to PSA it clearly is not the end all in determining the course of all prostate cancer. I have looked for and failed to find a good paper on how prostate cancer markers drop out or emerge over time. This would be very valuable data.

For example, in later stages of prostate Ca there may be a role for Chromogranin A (CgA) and Neuroson Specific Enolase (NSE) as neuroendocrine transformation raises its ugly head. In fact after a point it may be better to monitor for these markers than for PSA.

[ron_bucher]

My understanding is PSMA is not expressed in ~10-15% of cases, and in those cases an Axumin scan might find tumors. What is your oncologist saying about the MRI result?

I'm not aware of any method(s) to rule out existence of metastatic cancer while on ADT.

[icanwintwice in reply to ron_bucher]

My oncologist said he thought it was wrong which is why he ordered the PSMA test to follow. Its frustrating that your PSA can be undetectable, your testosterone can be 0, and you can have a PSMA test that shows 0 prostate cancer and you can still have metastatic prostate cancer. No wonder its so hard to beat this disease….

[ron_bucher in reply to icanwintwice]

I think any advanced cancer case is frustrating. Nobody wants such a “hobby”.

Live every day to the fullest.

[Seasid in reply to icanwintwice]

Maybe an FDG pet scan could show you if the cancer is still alive and there?

[Seasid in reply to Seasid]

An FDG PET scan is indeed a valuable tool for assessing whether cancer remains active, but its interpretation requires careful consideration. Here's a concise breakdown:

### How It Works:

- **FDG Uptake**: Cancer cells often exhibit high metabolic activity, leading them to absorb more fluorodeoxyglucose (FDG), a radioactive glucose analog. The PET scan detects this uptake, highlighting areas of potential malignancy.

### Key Uses:

1. **Detecting Residual Disease**: After treatment, it helps identify if active cancer remains.

2. **Monitoring Recurrence**: Useful for spotting cancer returning post-treatment.

3. **Assessing Treatment Response**: Measures metabolic changes to evaluate therapy effectiveness.

### Strengths:

- **Sensitivity**: Effective for many cancers (e.g., lung, lymphoma) that are highly FDG-avid.

- **Combined Imaging**: Often paired with CT (PET/CT) to correlate metabolic activity with anatomical details.

### Limitations:

- **False Positives**: Inflammation, infection, or healing tissue post-treatment can also uptake FDG, mimicking cancer.

- **False Negatives**: Some cancers (e.g., certain prostate, renal, or low-grade tumors) may not absorb FDG well.

- **Timing Matters**: Scans are typically delayed weeks after therapy to reduce inflammatory interference.

### Clinical Context:

- **Not Definitive Alone**: Results must be interpreted alongside clinical history, other imaging, and sometimes biopsies.

- **Follow-Up**: Abnormal findings may require additional tests (e.g., MRI, biopsy) or repeated scans over time.

### Conclusion:

An FDG PET scan can strongly suggest whether cancer is still active, but it is not foolproof. Specialists integrate its findings with other data to guide decisions. Always discuss results with your healthcare team to understand their implications fully.

AI said

[Schwah]

You said you still had a prostate. What was your original treatment to the prostate? The had a focal treatment (cryotherapy) to eradicate my cancer in about 40% of my prostate. Therefore I theoretically have 60% of a healthy prostate. I am n my second ‘vacation’ and my PSA has gone from undetectable to about 3 and stayed there for the last 6 months with no cancer in my PSMA scan not prostate showing up. My 4 PSA is theoretically from my healthy remaining prostate. Point being if your prostate was not 100% eradicated, your PSA may be from that remaining healthy prostate tissue and not cancer.

Schwah

[icanwintwice in reply to Schwah]

I had radiation to the prostate by way on Proton Therapy. I still have a prostate but its been fried to a crisp. One urologist is saying that I still have a prostate that might be enough to give out a reading. My PSA went from .0 to .1