Ga-68 PSMA PET/CT Imaging Issues

I stumbled across this page/video, PSMA PET/CT- Struggling with Increased Sensitivity, of a presentation about bringing Ga 68 PSMA PET/CT imaging online from the Society of Nuclear Medicine and Molecular Imaging (SNMMI) Annual Meeting. It’s definitely worth the 23 minutes to watch it if you have any interest in imaging for prostate cancer.

Ga 68 PSMA PET/CT scans definitely can see much more than current imaging technologies and is fast becoming the new “gold standard” of prostate cancer imaging. But, as with anything new, there are things we have to understand to use the technology to its full advantage and to not misinterpret what it’s telling us.

One of the statements in the presentation that struck me was, “Just because you can see it, doesn’t mean you should treat it.” The presenter described the following scenario:

“So this is a patient who’s eight years after a prostatectomy with rising PSA and when the gallium PSMA PET scan is done, we see focal intense uptake in a solitary mesorectal node, which measures two to three millimeters and we’re really seeing micro metastatic disease. And I think the title of the slide is just because you can see it, doesn’t mean you should treat it because we don’t know how long that lymph nodes been there for. This is not in the classical nodal dissection. This lymph node could have been there five years ago and maybe it hasn’t changed and we don’t know that. So it’s easy now to say let’s cut it out because we can see it or let’s give it stereotactic radiotherapy, but I look at an image like this and think if it’s taken eight years for this lymph node to get to two to three millimeters, this is extremely indolent disease and perhaps it’s best left alone.”

He also talked about early interventions taken as a result of the PSMA PET/CT scans that may have caused more problems for the patient than necessary without changing the outcome (i.e., continued recurrence after the procedure).

Again, I found this to be very enlightening as I’m heading into my appointment this week and considering going to UCLA for their PSMA trial.

 

PSMA-SRT Randomized Phase 3 Trial is now open at UCLA

Every now and again I’m asked to share information on my blog, and this was something that is of personal interest to me given my current situation. It’s from the UCLA Nuclear Medicine department and will likely be of interest to others as well.

They reference a couple of attachments in their email to me, but none were attached.


We have the pleasure to announce the opening of a Randomized Prospective phase 3 trial of PSMA PET/CT based salvage radiation therapy (PSMA-SRT) at UCLA Nuclear Medicine (NCT03582774).

https://clinicaltrials.gov/ct2/show/NCT03582774

This is the first randomized prospective phase 3 trial designed to determine whether PSMA PET/CT can improve outcomes in patients with prostate cancer biochemical recurrence.

PSMA PET/CT will be free of charge for patients (100% sponsored by UCLA Nuclear Medicine).

Patients who are planned for salvage radiation therapy (SRT) for recurrence after primary prostatectomy with PSA ≥ 0.1 ng/ml are candidate.

We will randomize patients to proceed with standard SRT (control arm 1) or undergo a PSMA PET/CT scan prior SRT planning (investigational arm 2).

Patients randomized to control arm 1 will not undergo PSMA PET/CT: SRT will be performed as routinely planned per discretion of the treating radiation oncologist. Any other imaging will be allowed for SRT planning if done per routine care.

Patients assigned to arm 2 will be scheduled to undergo a PSMA PET/CT scan at UCLA Nuclear Medicine (free of charge) prior to radiation therapy planning. DICOM images and reports of PSMA PET/CT scans will be delivered to the treating radiation oncologist.

The radiation oncologist may change the radiation plan depending on the findings of the PSMA PET/CT scan. That is, the treating radiation oncologist may use whatever dose, fractionation, and target volumes they choose, and may use concurrent ADT or not, at their discretion (please see the attached document for the radiation therapy management specifications).

The primary endpoint of the trial is the success rate of SRT measured as 5-year biochemical progression-free survival after initiation of SRT.

Patients will be followed by the UCLA Nuclear medicine research team for up to 5 years after initiation of SRT (phone/fax/secure emails with the treating radiation oncologist team and/or with the patient) every 3-6 months (routine PSA and imaging).

To enroll a patient:

  • All subjects must sign the UCLA IRB approved informed consent form (ICF, attached) before enrollment and randomization.
  • For UCLA patients, this will be done after a consultation with the UCLA Nuclear Medicine Team or the UCLA Radiation Oncology Team.
  • For all other patients outside of UCLA, this will be done after a phone consultation with the UCLA nuclear medicine research team. Signed ICF will then be obtained by fax or email.
  • The randomization number and assigned arm will be communicated by phone or email to treating physicians and patients one day after the enrollment.
  • Patients randomized to control arm 1 will not need to come at UCLA and will receive SRT per routine care at the treating radiation oncologist institution.

This trial represents a good opportunity for all the patients who cannot afford the out-of-pocket costs of a research PSMA PET/CT (at UCLA: around $2700).

Please try to spread the word as much as you can around you.

In advance I thank you very much for your collaboration.

Please don’t hesitate to contact us if you have any question:

Jeaninne Gartmann, Study Coordinator: JGartmann@mednet.ucla.edu
Jeremie Calais, Principal Investigator: JCalais@mednet.ucla.edu
Nicholas Nickols, Co-Principal Investigator: NNickols@mednet.ucla.edu

Best regards

Jeremie Calais MD MSc
Assistant Professor
UCLA Nuclear Medicine

Day 2,717 – The Discussion

I hate this flippin’ disease.

My discussion with my urologist went pretty much exactly as I suspected it would, but with a few twists to screw with my mind a little. One of those little twists, however, happened much earlier than the meeting.

This morning as I was shaving, there was this strong sense of fear that hit me, tying my stomach in knots. That was completely unexpected and unfounded because I had a good idea of what was going to happen with the doctor. Even so, it was something that took control and definitely set my mood for the day.

When the doctor entered the exam room, I told him about my propensity to just verbally vomit all over the doctors before they even had a chance to explain their interpretation of my results. I shut up and let him talk away (with my battery of questions at the ready on my lap).

Pretty much everything that he said were things that I already knew:

  • The increasing PSA is a concern, but the slow rate of increase is a good thing.
  • That salvage radiotherapy would be the likely next step.
  • Given my pathology and history, it’s likely that the cancer is still in the prostate fossa.
  • Starting salvage radiotherapy earlier rather than later has typically shown to have better outcomes.
  • We have no guarantee of knowing where the cancer is at, so the radiotherapy may be ineffective.
  • Current imaging technologies aren’t good enough to detect the cancer’s location.
  • There’s no cut-and-dry set of numbers that would dictate specific actions.

The one kicker that knocked me for a loop was something that he said as we were reviewing my PSA tracking chart (I had to bring a copy of that, of course). He did mention the possibility that what we’re tracking may actually be benign prostatic tissue left behind that’s causing the PSA to rise. His reasoning was the fact that it took 54 months for the PSA to become detectable again and its slow rise ever since. He suspected that if the cancer was returning, the PSA would be climbing more rapidly. That, of course, would be great news. He didn’t assign a probability to his theory being right, however.

He did ask if I would be open to a referral to a radiation oncologist to at least begin the discussion and get educated. I said that, if he hadn’t suggested it, I was going to request it, so, yes, I was open to the referral. I don’t have an appointment on the calendar for that yet—they should call in the next few days.

I did mention the PSMA imaging trial that’s going on at UCLA and he was supportive of me looking into it. He cautioned, though that it is a trial and there’s no way to know yet how effective it may be. To be honest, it’s been a while since I looked at the trial page and I’m not sure that I would qualify to participate if it’s still ongoing. Something to dig into.

Lastly, he said there’s no need for urgent action at the moment. We’ll continue the four-month PSA test cycle for now. That will have me in the lab the first week of August.

When you get your care through the Veterans Administration (VA), as I do, you rarely see the same doctor twice. I mentioned that to this urologist and commented that, in a way, it’s a good thing because I’m getting multiple opinions and perspectives. He was taken aback by that comment, saying, “That’s a charitable view. I usually hear the opposite.”

He’s the second doctor who’s mentioned the possibility of this being nothing more than benign prostate tissue left behind that’s causing the PSA to return and rise. Perhaps I need to put a little more stock in that theory. But after spending two years wrapping my head around the notion that the cancer is returning—a mentally and emotionally exhausting exercise—when you hear something like this, it really screws with your mind. Or at least it does mine. It’s one more variable added to an ocean of uncertainty when you’re desperately seeking solid land.

The good thing is that I have time, and time may bring a little more clarity on which to base a decision at some point in the future. In the meantime, I’ll just don my kapok life preserver and bob around in that ocean of uncertainty reflecting on how much I hate this flippin’ disease. (Yes, I’m dating myself with the kapok reference.)