What is a "normal" max SUV on PSMA-Pet scan?

[Adendino]

I'm trying to learn more about PSMA Pet scans and max/mean SUV uptake in the prostate. For those of you who have done a PSMA-PET scan and are high gleason score (8-10), can you share what your max SUV of the prostate was in your scan? My husbands prostate had a max SUV of only 7.5 and I'm trying to figure out where on the scale this falls (low, mid, or high), and whether this is considered a low SUV for PSMA uptake? Thanks for sharing.

[Tall_Allen]

It depends on the background uptake. The radiologist report should alert you to what is concerning and what isn't.

[Adendino in reply to Tall_Allen]

Thanks for your prompt reply. I've been hearing that several rare types of prostate cancer (intraductal, ductal for example) don't express as much PSMA and therefore might not be receptive to some types of treatment. My husband's PSA was relatively low for a Gleason 9 (it was only 11.5) so I've been reviewing his PSMA pet scan to see if I could learn more about his SUV uptake. The report said:

PET FINDINGS:

Blood pool SUVmean: 1.1

Liver SUVmean: 5.9

Parotid SUVmean: 16

ABDOMEN AND PELVIS:

++Focal avidity within the mid anterior prostate on image 244 just to the left of midline has a max SUV of 7.6.

***Milder increased activity is present within the seminal vesicles bilaterally, max SUV on the right 4.4 and left 3.7.

[Tall_Allen in reply to Adendino]

Prostate and Seminal vesicle uptake is too low to be definitive -the radiotracer is urinarily excreted so subject to false positives in that area unless really high.

What does the radiology report say? Neither you nor I are experts at reading them but the radiologist is the expert. If you don't trust his report, you can get a second opinion from someone who is more expert.

[Mark89 in reply to Tall_Allen]

my father recently diagnosed as Localized prostate cancer .

Intial PSA level 8

He did prosate MRI reported as BIRAD 4 ( Right side Nodule ) , No extracapsular invasion and No Lymph nodes Involvement , no seminal vesicles involvement .

then he underwent prsoate biopsy and confirmed prostate adenocarcinoma Geleson scor 8 ( 4+4 )

later he did PSMA Scan which reported :

Enalrged prostate gland showing diffuse heterogeneous moderately increased(68) Ga-PSMA activity with no definite focal lesions and SUVmax=10.58. However, on delayed images, there is a diffuse heterogeneous mildly increased (68) Ga-PSMA prostatic activity with SUVmax=3.78, and a two foci of nearly symmetrical mildly increased (68)Ga-PSMA activity noted in both seminal vesicles with SUVmax up to 4.78.

what do you think about two foci of nearly symmetrical noted in both seminal vesicles , is it false postive !?

Thanks .

[Tall_Allen in reply to Mark89]

Probably. Clue is "delayed images."

[tango65]

There are 3 main normal SUVs: blood pool (descending aorta blood ), the SUVS of the liver and the AUV of the salivary glands.

Low PSMA expression is anything similar to blood pool, moderate PSMA expression is a SUV around the liver SUV, high PSMA expression is SUV around value of the SUV of the parotid glands.

[Jancapper]

G9 here as well. Initial PSA was 14.5.The left lateral prostate gland contains an intensely avid 12 x 14 mm focus of radiotracer activity compatible with known prostate neoplasm. SUV maximum measures 13.58 (image 2:52). No avid or enlarged intra-abdominal lymph nodes by CT size criteria.

[maley2711]

You can probably find more studies than the 1-2 I have looked at........I remember one mentioned an SUVmax of 8-8.5 as a breakpoint for showing higher Gleason cancer.....more studies are needed, and they may or may not sometime show definitive results for using prostate SUVmax as a clinical decision tool. Certainly, cancer is not excluded if a man's SUVmax is less than 8.5.....mine was approx that number.....overall it seems a man would have more hope the lower the SUVmax. For now, I don't think data is in to use prostate SUVmax as a decision marker???

If you want to learn more than what you can pick up here, I find Google and pubmed.com, and appropriate search terms, are incredibly helpful for questions such as yours....but easy to be bogged down in reading materials......it is too bad we can't have absolute confidence that the "average" urologist or RO hasn't absorbed the very latest in research about PCa diagnosis and treatment... the majority of men simply aren't going to be diagnosed or treated at the vaunted centers of excellence.

[Tony666]

Gleason 9 here. But small amount (only 2 cores of less than 25% each). Psa of 9. Pet scan on diagnosis was suv max of 6.6 on right side of prostate (where the Gleason 9 was) and 4.1 on left side.

[jswhite in reply to Tony666]

I have PSMA PetScan scores 11.0 for prostate, 5.7 for liver and 1.1 for a lesion in my rib. Gleason 7 Is the rib likely to be metastaic disease? Is there a PSMA PETScan SUV cutoff for cancer or not?

[Tony666 in reply to jswhite]

not sure.

[maley2711]

coincidence....... I just noticed this open tab on my computer......

ncbi.nlm.nih.gov/pmc/articl...

small study...maybe something like what you inquired about?

[MateoBeach]

The SUVmax in your husband’s prostate is not a concern since you already know he has localized prostate cancer in the gland. And that he is going to be appropriately treated with whole prostate radiation in January, including seminal vesicles. The PSMA PET scan was no doubt done to see if there is evidence of existing spread (metastasis) to OTHER sites beyond the prostate. That would have changed the treatment plan. Evidently, no other sites were seen, so he is good to go with the radiation treatment plan with short term ADT in support.

[Adendino in reply to MateoBeach]

Thanks for your insight, I appreciate it. He also has “intraductal carcinoma” and I’ve been hearing that this means he might not respond favorably to some treatments and his cancer doesn’t express a lot of PSMA. My concern was whether his PSMA scan might give any hints about whether this should be taken into account. Paranoia and over-researching is something I have to manage during this process… this new prostate cancer diagnosis of Gleason 9 has presented me with a new vocabulary and reality and provokes many questions. Thanks again!

[Deadstick]

Hi,

My understanding is that the SUV max will also depend on the ligand (radionuclide) used. Iluccix is Gallium 68 and Pylarify is fluorine based. The radiologist or the nuclear medicine docs are the experts. As others have said, it never hurts to get another opinion.

[Gmailer]

Mine was 28.3 at first. Dx'd in August, 2014. After my first vaccine went down to 14 so I was pretty happy. My PSA was 212 at first. It's been pretty crazy at times, but the India vaccines really helped me. Now I am on Keytruda and Zytiga. PSA is .07 so we know it's still there. I don't remember my old user ID or password but I'm the same guy that did the vaccines in India. Lupron I was on for under two years. It still worked but just about killed me. Lucky to still be here. I had a radical prostatectomy over 3 years ago in Delhi. Hard surgery.

I guess 28.3 SUV is pretty high. Glad your husband has something better to look at.

[Gmailer]

Also, the doctor that was behind the vaccines I had in India is now doing them in Cancun. On Facebook it's under Immunocine. They are more than in India, but they can really save you. They use an old treatment of MRNA that took over a decade to make it. Thankfully it really helped me, even though I'm not cured, and may never be. I can't complain after being alive over 8 years now with it. Had 35 days with COVID with a stroke in the hospital. Being intubated for a few days wasn't fun. Lucky I'm alive.

Chris