PSMA PET Scans...some interesting info

Thanks for sharing that. Here in Ontario, PSMA-PET hasn't become standard yet: it is available, but it's not automatic, and tends to be reserved for complex or exceptional cases.

When I asked my radiation oncologist about it, he said "The problem is that we don't know what to do with the results." I see that the article is saying the same thing: as far as they can tell so far (it's very early days), much of the stuff that lights up on PSMA-PET but not CT and/or bone scans never develops into anything serious, so what do you do with that extra info?

"Here's somewhere a serious tumour might develop some day … maybe … but probably (?) not … so, um …" 😕

Great article and it seems that in big centers it is already a known fact and they are acting accordingly.

As with any new technology ( or a new medication for that matter) over time things start to become more clear regarding both effectiveness and safety.

I was upset that at our treatment center doctors declared faintly glowing node as not effected by PC but now I can see why and it would change staging significantly. So far it seems that they were right since post op ultra sensitive PSA came so low (knock the wood). No test can replace doctor's experience and no test alone can show the whole picture.

I also like the explanation of metastatic PC lesions - they are not all the same either ! Some can be indolent for many years, same as are some lesions in a prostate. That is very encouraging indeed.

Bottom line, go to big cancer treatment centers if at all possible or at least go there to have a second opinion.

@northoftheborder A confusing bit of information isn't it? How do we actively surveil metastases if they might not require immediate treatment?

The article left me feeling that multiple opinions, supplement MRI and perhaps some genetic testing , all together with the PSMA Pet might be a reasonable course of action to get to a fair and somewhat accurate diagnosis.

What they don’t mention in this paper when comparing conventional imaging (bone/CT) to next generation imaging (PSMA PET) is what the SUVmax scores were in the PSMA PET imaging: were they less than or greater than each patients’ background blood, liver, and parotid gland SUVmax scores? That matters when determining next treatment steps.

Dr. Johnson (of Mayo Clinic) talks about all this in his presentation, starting with the scans we’ve all heard about (MRI, bone, & CT scans), and then going into detail about PSMA PET scans: https://youtu.be/JoJomACA5UM

Good find with this article…raises many, many questions and at the same time casts doubt on other areas once considered a certainty…oh well…

@callibaetis Exactly. It's a bit like general germline genetic testing (not specifically after a cancer diagnosis).

"We found a mutation that means you have an elevated chance of developing disease X at some point in your life."

"Can I do anything about it?"

"Nope."

"So what do I do with this information."

"I dunno. Make sure your insurance company doesn't find out?"

@heavyphil It's probably on a similar trajectory to PSA testing, following the Gartner hype curve. First they find a new diagnostic tool and get very excited. Then they over-apply it. Then a reaction kicks in and they stop using it as much as they should. Then finally they figure out how to fit it in with the rest of the ecosystem and make it genuinely useful.

PSA testing fell into the Trough of Disillusionment 10-15 years ago, because doctors were making too aggressive treatment choices (especially for older patients) based on only mildly-elevated PSA readings. As a result, health authorities stopped recommending routine PSA screening in most countries, and the number of de-novo *advanced* prostate cancer cases shot up through the roof (because they starting missing the more-serious cases). Now they're cautiously moving back towards routine screening, but without an overreaction to a mildly-elevated PSA, with new options like active surveillance.

I'd say that PSMA-PET scans are currently teetering at the top of the Peak of Inflated Expectations, and there will be a strong reaction to over-treatment (like radiating every little spot that lights up "just in case"), but eventually it will find its place.

@northoftheborder With PSMA PET scans there are different levels of “lighting up.” The level of “lighting up” is reported in a SUVmax score. The lower the SUVmax score, the less aggressive the prostate cancer; the higher the SUVmax score, the more aggressive the prostate cancer.

@brianjarvis absolutely true…but infected/inflamed tissues can also have higher than normal SUV’s. This becomes very subjective when talking about lymph glands - tissue which, by nature, is reactive/inflamed in cases of infection, allergy and cancer.
So the rationale for using PSA velocity becomes even more important, right?
I am not an RO, but will a PSMA show a discernible SUV increase in a lymph gland at a 3 month interval? If so, that change -coupled with a higher PSA- would indicate a growing PCa and necessary treatment.
Phil