I wanted to check if anyone has had such a high SUVmax on a PSMA-PET? My father's recent scan shows a new lesion in the perirectal region with an SUVmax of 80.1. Everywhere I have searched, I can't find anyone with such high SUVmax. ChatGPT tells me this is highly unusual. His PSA has risen from 0.6 to 3.6 in about 4 months. No pain or any other symptoms. He has mets all over his bones since 2021. This lesion in the rectum is new.
Could the PET scan have an error? Wanted to check if we should repeat it at a better hospital. Or is this a very highly aggresive lesion?
Thanks in advance
Rodeoz
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Rodeoz15
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My husband had very high suv max values into the 70s before pluvicto. He finished 6 rounds of pluvicto with mixed results with a lot of the mets getting smaller or resolving. One bone met which only had an suv max of 4.2 grew like crazy while he was on Pluvicto and now he will get radiation. If your dad can handle the treatment, pluvicto should help the super avid ones.
Not sure if the PSMA could have any error - wouldn’t think so ? I had a PSMA Pet scan on Monday. It showed up a lesion on 8 th rib with SUV max 15.9 , another on left hip bone with SUV max20.2 and a possible lesion on skull of SUV max 2.3 (at left parieto-occipital skull but could be flare of blood vessel activity at adjacent venous sinus) on which I had a CT scan yesterday & will find out about that on Tuesday. I will have SBRT radiation on these as I have done on two other lesions. The oncologist said these were almost in the lower range and greater than 20 could cause a problem. Best wishes.
The scan that convinced me to do 177Lu therapy had many lymph nodes in the 60s and one as high as 114. GP24 posted here about a clinical trial of Pluvicto for the hormone sensitive state. I had an excellent response but my disease is lymph compared to your bone.
I had a few mets in the spine with SuvMax 60's & 70's after PSA went from 1 to 5, then went down to 8 after SBRT.
One of the mets with pain, and broke a vertebrae.
I was going to do Lu177 but did SBRT which is more effective in oligometastatic Bone lesions.
PSA went down to 0.8
While the SBRT, I did one cycle of Keytruda, in hope of getting an abscopal effect.
When PSA went down to 0.8 four months after SBRT, I stopped Enza and 4 weeks later started BAT with Testosterone monthly during two shots.
I can't give advice, but in your case I think I would try SBRT to the aggressive lessons plus Lu177 one cycle and one shot of Keytruda at the same time. It is not the protocol, but I've done it once, and would do it again.
Keytruda side effects were quite annoying but transient (neutropenia, fever, meningitis simptoms, skin issues with peripheral neuropathy in face and ears, fungi infections). As well as esophagitis grade 2 due to SBRT
I went with Keytruda. It enhances TILs proliferation and possible abscopal effect.Did only one cycle with SBRT, it is very expensive. I did not go with Olaparib, I spent money in genetic tests , one liquid and two of old biopsies. All negative in mutations. So Olaparib wouldn't be cost/effective, sonI went with keytruda. Maybe it was money down the drain anyway.
During the SBRT irradiation the cancer would go through DNA damage. I am not a doctor but if I could do it I would do parp inhibitors during radiation treatment with SBRT. I asked my RO about olaparib during my SBRT irradiation of my prostate with MRI Linac Elekta Unity machine but he said no.
Q. Why is it an uncharted territory combining high precision MRI Linac with olaparib in order to kill the cancer in the prostate? I see big benefits killing the cancer in my prostate.
A. You're right to see potential benefits in combining olaparib with SBRT on an MRI-Linac. The idea is scientifically sound—radiation causes DNA damage, and olaparib blocks the repair, increasing cancer cell death. But here’s why it might be considered "uncharted territory":
1. Limited Clinical Trial Data – While there’s growing evidence for combining PARP inhibitors with radiation, most studies focus on standard external beam radiation, not ultra-high precision SBRT on an MRI-Linac. Your oncologist may be reluctant because the exact toxicity profile and efficacy in this specific setting aren’t well established.
2. Potential Toxicity Risks – SBRT delivers high doses per fraction, causing significant DNA damage. Adding olaparib could amplify toxicity to surrounding tissues, especially in the bladder, rectum, and urethra. MRI-Linac improves precision, but there’s still a risk of unexpected side effects.
3. Regulatory and Institutional Barriers – Using olaparib off-label with SBRT might require ethics approvals or inclusion in a clinical trial. Many oncologists won’t prescribe combinations without established protocols.
4. Lack of Biomarker-Driven Patient Selection – Most studies on olaparib focus on BRCA1/2 or HRR-deficient tumors. If your cancer doesn’t have these mutations, your oncologist may doubt the benefit.
You seem to be thinking ahead of current clinical practice. If you’re still interested in this approach, one option is to find a clinical trial investigating PARP inhibitors with SBRT in prostate cancer. Would you like me to check for any open trials in Australia?
Q. If the MRI Linac machine is high precision than then wouldn't be the surrounding organs spared from side effects of the SBRT irradiation?
A. Yes, that’s exactly the advantage of an MRI-Linac—it provides real-time imaging, allowing for adaptive radiation delivery that spares surrounding organs more effectively than traditional methods. This should, in theory, reduce toxicity to the bladder, rectum, and urethra.
However, the concern with adding olaparib isn’t just radiation exposure to surrounding tissues but rather systemic toxicity and synergistic effects on normal tissues:
1. Systemic Effects of Olaparib – Unlike radiation, which is highly localized, olaparib circulates throughout the body. Even if the radiation is precisely targeted, olaparib could still affect normal tissues that naturally experience DNA damage and rely on repair mechanisms (e.g., bone marrow, gastrointestinal lining).
2. Increased Normal Tissue Sensitivity – While MRI-Linac minimizes dose to surrounding tissues, it can’t eliminate all exposure. PARP inhibitors could make even small doses of radiation more toxic to nearby healthy cells, potentially increasing late rectal and bladder side effects.
3. Unknown Interaction with High Dose Per Fraction SBRT – SBRT delivers a much higher dose per fraction than conventional radiation. The combination with olaparib could cause unexpected or more severe toxicities, which haven’t been fully studied in this setting.
If toxicity risks were manageable, MRI-Linac + SBRT + olaparib could be a powerful combination, particularly in high-risk cases. But without data from well-designed clinical trials, oncologists are hesitant to use it outside of experimental settings.
Would you be interested in searching for trials testing olaparib with SBRT? Even if they don’t use MRI-Linac, the results could push the field in that direction.
Don't panic. I just found my husband's PSMA scan results where he had a lymph node show an SUV of 125 and another of 32. They may have disappeared entirely during chemo as they have not been mentioned in following scans.
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