MRI negative findings contradict PSMA PET/CT finding of likely disease recurrence within prostate.

[ac61418]

Diagnosed with Gleason 9 PCa , PSA 6.7, in 2018. Treated with 81 GY EBRT and Firmagon ADT. PSA subsequently dropped to nadir (<0.02) in Nov 2019. Since then steady rise to PSA 1.0 in July 2022. PSA doubling time from 0.5 to 1.0 in 7 months, suspicion for recurrence.

Did a Pylarify PSMA PT/CT that found hot spots within the prostate (SUV 20.2) and bilateral internal iliac regions (SUV 1.9) indicating likely disease recurrence within the prostate..

Did a follow-up 3T mpMRI w/wo contrast to confirm PSMA findings. However, MRI findings were negative--"Impression: 1. No suspicious prostate lesion seen. 2. No evidence of adenopathy. 3. Correlation previous PET/CT suggested. 4. PI-RADS Category 2."

What should I do next?

Any feedback or suggestions appreciated.

[Tall_Allen]

You have to biopsy the suspicious area.

[rococo]

I agree. Before any treatment you always do a biopsy, It may a false pos. from inflammation caused by the radiation

[cesces]

2 to 1

PSA and psma vs MRI

Please let us know what happens when you get a biopsy

[NotDFL]

Your PSA is still quite low for someone with a prostate. The usual criterion for action is nadir +2. Let's hope your PSA will stabilize in that range. Other than following up with frequent PSA tests, I would just relax for the time being.

[ac61418 in reply to NotDFL]

I think the ASTRO guideline needs updating. My URO doc was following a longtime patient who received RT years ago with PSA monitoring that were stable at 1.4. Based on ASTRO criterion, told patient he was doing fine. Fast forward later on, patient complained about back pain. Imaging gave shocking bad news that not only did PCa metastasize, but had spread all over pelvic bones during the PSA monitoring periods. Doc said that small percentage (around 10%) of PCa do not exhibit PSA, usually the aggressive and deadlier types. Thanks for your positive outlook but given my Gleason 9 and fast PSADT the odds may not be in my favor. Am hopeful that the PSMA hotspot may be transient inflammation (as noted by rococo earlier) that has subsided since the two scans were done five weeks apart.

[NotDFL in reply to ac61418]

Patients that have undergone radiation therapy often have 'bounces'. Although I cannot exclude that something more serious is happening, let's hope your PSA will stabilize. My prostate was irradiated to bits (Gleason 9; SBRT + IMRT) and has undergone one bounce so far. My current PSA is 1.2 ng/mL. I agree that this does not mean much for your situation. Still hoping that your PSA will level out.

[ac61418 in reply to NotDFL]

There is a study you can find online showing men who experienced PSA bounce the first few years after RT (including brachy) have better outcomes and long term survival. The theory is that the remaining irradiated PCa cells have a last gasp moment before dying off causing the bounce. Hopeful that this be your case and that you are cured! I did not experience any bounce after RT. The PSA rose steadily from nadir.

[ac61418]

Does anyone know of any comparison studies of 3T MRI vs PSMA PET/CT detection sensitivity for irradiated prostate and if the newest 8T MRI is becoming available anytime soon?

Does anyone have experience with the 29mhz Micro ultrasound offered at Fox Chase and/or Color Doppler Ultrasound procedures to confirm my conflicting results? Thinking of these two modalities, I am in NJ, anyone know of a facility that offers the Color Doppler nearby?