Pylarify PSMA PET/CT Results---Feedback

[ac61418]

Hello All, new member. I received my scan results and I am asking for any feedback:

Tech History: Restaging prostate cancer.

History:

The patient is a 65-year-old male with prostate carcinoma 2018, Gleason 9, wide field radiotherapy, now with rising PSA at 1.0, assess

for source of elevated PSA.

Technique:

DOSE: 9.74 mCi of PYLARIFY.

INJECTION SITE: LAC

Technique:

Intravenous access was established. The patient was administered 9.74 mCi of PYLARIFY (F18 Piflufolastat) intravenously, 3-D

acquisition protocol. A PET scan from the orbits to the upper thigh was obtained utilizing a True Digital Solid State TOF PET scanner,

GE Discovery MI. A limited low dose CT scan was also acquired of the same region solely for the purposes of attenuation correction

of the PET images and anatomic co-registration with the PET/CT images; while utilizing a number of dose reduction techniques, SmartMA / ASIR.

All data were reconstructed in the transverse, sagittal, and coronal planes.

A detailed image atlas, an integral part of the report, was printed directly referring to the current study, while utilizing the unparalleled

ATLAS3 system of lesion tracking.

Comparison none

Findings:

Head/Neck:

PET images of the head demonstrate expected intense physiologic glandular activities, adenoidal activities and to a lesser extent vocal

cord activities. Physiologic nerve root activities and cervical ganglia appreciated.

Suspect thyroid unremarkable

Chest:

Periclavicular region, anterior chest wall, breast and axillary regions without evidence of malignancy on PET.

Mediastinum and lung parenchyma without evidence of malignancy on PET.

Abdomen/Pelvis:

Kidneys demonstrate no evidence of functional obstruction to urine outflow.

More likely to represent a left sacral ganglia, less likely a malignant node in the internal iliac distribution, is a 4.2 x 6.3 mm density

SUV 1.9 image 262.

Similar structures suggested on the right in a similar location with a similar level of uptake.

Towards the apical region of the prostate/superior penile bulb perhaps biased just left of midline a 11.0 mm focal uptake is seen on

image 202/204, the area of uptake on CT vaguely correlates to a potential 14.4 mm density.

The SUV value is 20.2.

The finding more likely represents disease and/or less likely urine activity.

Skeleton:

Visualized skeletal system without evidence of malignancy on PET.

Impression:

Towards the apical region of the prostate/superior penile bulb perhaps biased just left of midline an intense focal uptake is seen.

The finding more likely represents disease and/or less likely urine activity.

In the left iliac distribution what more likely represents a benign left sacral ganglia is present.

Any Feedback and/or Recommendations on what I should do next is appreciated. Thanks.

[tango65]

Possible cancer in the apical part of the prostate.

The problem with these PSMA PET/CT ligands used in the USA is that the tracer is eliminated by the urine making difficult to interpreter lesions in the prostate.

Since the SUV of this finding is 20 (high) I would discuss having mpMRI of the prostate.

Since the Gleason was 9, if this is cancer most probable will show in a mpMRI.

I would also discuss having a 3T MRI of the pelvis (there are 2 large possible lesions with very low SUV).

[ac61418 in reply to tango65]

Tango65, Thanks for your recommendation. I did have a 3T mpMRI with Dotarem in Sept 2021 (negative ) when my PSA was 0.3, rising from nadir of undetectable (<0.02) in Nov 2019. I estimate my PSADT from 0.5 to 1.0 to be 7.4 mos. Do I need to ask for MRI of the prostate + pelvis, or does the prostate MRI usually include iliac distribution? Also I am concerned about gadolinium contrast bioaccumulation as this will be my 3rd MRI with contrast. Is it possible to do the MRI without contrast as I understand it adds small benefit compared to the unknown risk of bioaccumulation?

[tango65 in reply to ac61418]

The mpMRi requires gadolinium. If you are afraid of Gadolinium accumulation you could request a biopsy based only in the results of PET/CT. This decision could be supported by a recent publication which did not find major differences between both techniques.

ejhi.springeropen.com/artic...

[Tall_Allen]

The good news is that the recurrence seems to be limited to that one site at the apex of your prostate. That apex recurrence may be a good place to do some focal salvage brachytherapy. Talk to a brachytherapy expert. The risk is the penile bulb dose, which could cause erectile dysfunction.

[ac61418 in reply to Tall_Allen]

Tall_Allen, thanks for your feedback. After I get the 3T mpMRI would I need a biopsy of the area in question assuming it is accessible, prior to searching for a brachy expert? As I am concerned about erectile dysfunction are there other focal therapies such as Cryo, HFU or salvage radiation, that I should consider, in addition to systemic ADT? Also, should I request a re-read of the Pylarify scan at a COE to confirm the findings?

[Tall_Allen in reply to ac61418]

I think a biopsy is a good idea- not only to confirm that site, but to make sure it hasn't spread microscopically around the prostate.

As for other salvage modalities, see the table at the end:

prostatecancer.news/2017/09...

The problem with salvage cryo or HIFU is that the recurrence rate (due to incomplete ablation) is very high. Salvage IRE looks pretty good, although the impotence rate is very high. Low dose rate brachytherapy (maybe using Cs131) probably has the best odds of destroying the cancer, and, unlike the thermal therapies, may spare the other tissues. But the location is less than ideal for erectile function preservation.

[ac61418 in reply to Tall_Allen]

Thanks for the info. Any thoughts about using LU177 psma for focal therapy? I read one post online that said this was his primary treatment and that it can be used for all stages in Germany, but I have not confirmed this as fact. What do you think about ADT as an alternative, realizing it will not cure only control the PCa?

[Tall_Allen in reply to ac61418]

Pluvicto cannot be used for local therapy. The risk is that some of the cancer does not express PSMA.

Lifelong ADT is definitely an option. But since it ends your libido, what is the advantage?

[Hidden]

Major cause of ED in PCa patients is the damage to the vascular network required for an erection. All of the techniques you wrote about cause some damage. Move on and treat your disease. With that said, a twice weekly dose of 12 to 25 mg of Viagra help to minimize damage and actually foster the growth of new capillaries.

I did this commencing in 2003. In my opinion, it worked. Ran it by my Radiation Oncologists and Cardiologist. They all said that it could not hurt and just may help. Physiologically speaking, it is sound...... som if it works for you, great. If it doesn’t, move on and treat your cancer and keep killing the little bastards. Besides, given the Buddy Hackett routine, you can always transplant an elephants trunk.......

GD

[Gabby643 in reply to Hidden]

Buddy Hackett, good guy

[ac61418]

Interesting development, did the follow-up 3T mp MRI w/wo contrast--

"Impression:

1. No suspicious prostate lesion seen.

2. No evidence of adenopathy.3. Correlation previous PET?CT suggested.

4. PI-RADS Category 2.

Were the PSMA PET/CT SUV findings a false positive?

What should I do next?

Thanks in advance.