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Advanced Prostate Cancer

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"Bombesin - A New Frontier for Prostate Cancer Imaging"

tango65 profile image
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They are studying the imaging of prostate cancer with Ga 68 gastrin-releasing peptide receptor antagonists PET/CTs (Ga 68 -RM2). If this approach works, they will be able to treat PC with Lu 177 RM2 or similar. The treatment with Lu 177 could extend to PCs with low PSMA expression.

urotoday.com/center-of-exce...

There are several clinical trials for PET/CT studies using Ga68-RM2:

clinicaltrials.gov/ct2/resu...

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tango65
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NPfisherman profile image
NPfisherman

Tango65--thanks for posting your science--my question is that it looked like they were imaging people down to a 0.2 PSA but question that PSA value should matter at all...I may put out a call to the contact at Stanford tomorrow to see if it is possible to participate with a PSA below 0.1.... Are you aware of anyone imaging at an "undetectable" level ?? Thanks for any insight you can provide...

Fish

tango65 profile image
tango65 in reply to NPfisherman

The trial at Stanford requires a PSA of 0.2 or higher.

It seems that they are doing Ga 68 PSMA PET/CTs with a PSA <0.2 at Saglik Bilimleri University Diyarbakir, Turkey.

They found Ga 68 PSMA PET/CT has a detection rate of 43% with a PSA <0.2

ncbi.nlm.nih.gov/pubmed/310...

I wonder if in Germany, Austria, Australia and/or South Africa are doing the same.

NPfisherman profile image
NPfisherman in reply to tango65

I am watching for the fibrinogen activation protein scan to be available in Heidelberg....it can detect 30 different cancers so if you're gonna get a screening, then make it a big one....my concern is the micrometastasis or very small tumors and how to detect those while PCa is under substantial control....How can we slay the beast when he can not be found so easily?? Thanks for the reply....

Fish

tango65 profile image
tango65 in reply to NPfisherman

It goes beyond my pay grade, but I believe the detection of very small mestastases is impossible wih the minimal spatial resolution of the PET machines available (around 4 mm). Some machines could have a spatial resolution of 2.5 mm. Whatever the target or the ligand it wiill be impossible to detect smaller metastases.

The Ga68 FAPI PET/CT scan is already available iat Heidelberg and it seems to work in PC.

ncbi.nlm.nih.gov/pubmed/309...

sci-hub.tw/http://jnm.snmjo...

NPfisherman profile image
NPfisherman in reply to tango65

Yes, I put this science on the forum a month ago:

healthunlocked.com/advanced...

I did not realize that PET/CT can only get to 2.5 mm at the best--the radioligand attachment then becomes the real key to slaying the beast because it should migrate to extremely small tumors--The FAPI-LU177/ FAPI AC-225 treatment is what is needed...

Thanks for your reply--guess I will wait for the FAPI radioligands to materialize in Heidelberg... then, go place an order....

I'd like some mixed FAPI radioligand treatments with some hyperthermia, and a cappuccino with almond milk and some toffee nut flavored syrup, please.....

Sound good?? Thanks for replying.... Have a great weekend....

Fish

GP24 profile image
GP24 in reply to tango65

In Germany you usually wait until the PSA gets above 0.5, or better to 1.0 before starting with a PSMA PET/CT. I know Munich will do it at 0.2 if the insurance pays for it. However, you will usually see only a small fraction of the existing mets if you make a PSMA PET/CT at a PSA value that low. So if you have to pay for it yourself, you better wait for a higher PSA value to get a better result.

The question for me is, should you really start radiating at 0.2 ng/ml in a recurrence situation? This is based on data which is quite old and today radiation is done with IMRT and higher doses and could be combined with six months of ADT. Then you may have the same or better results as in "the old days" when these statistics were made. This would allow to wait until the PSA value reaches 0.5 ng/ml. The PSMA PET/CT will allow to decide if you just radiate the prostate bed or include the pelvic lymph nodes. Or no radiation if you find small bone mets.

Amling found that the PSA value often stabilizes at 0.4 ng/ml and recommends to define a PSA value of 0.4 ng/ml as a cut point for recurrence. This would suggest to wait until the PSA value gets above 0.4 and make the PSMA PET/CT then.

ncbi.nlm.nih.gov/pubmed/112...

jdm3 profile image
jdm3 in reply to GP24

Interesting that it stabilizes at 0.4. This begs the age-old question of what to consider the cutoff point for BCR after ADT, or chemo, or radiation (instead of or in addition to surgery). My MO said he will wait until 0.5. Perhaps they are seeing similar stabilization after a variety of treatments.

GP24 profile image
GP24 in reply to jdm3

The guidelines usually state that after surgery the salvage radiation should start at a PSA value between 0.2 and 0.5 ng/ml. Many doctors wait until 0.5 and hope it may stabilize below that. On the other hand, some prefer to start at 0.1 ng/ml. I suspect this low level results in overtreatment for many patients.

After radiation or chemo the 0.2-0.5 ng/ml cut off does not apply.

keepinon profile image
keepinon in reply to NPfisherman

Fish. If you contact Stanford could you let me know what they say. I am in Sacramento waiting for SRT with .1 PSA. On ADT. Thanks. Bill

Fanger1 profile image
Fanger1

Hello Tango,

Thank you for posting this research presentation from Dr. Iagaru at Stanford. Sounds like Bombesin is promising for imaging and future treatment. Nice to also know about the clinical trials being curre

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