I came across this video highlighting Ga68 PSMA PET imaging from the doctor at the University of California San Francisco who helped with developing this imaging technique. It’s a bit long and a bit technical in some places, but gives a good overview.
Today was a tough day. The news of my PSA increasing to 0.21 ng/ml weighed heavily on me throughout the day. It even made me a little snippy in a meeting this morning, as my tolerance for trivial bullsh*t decreased to an all-time low. Oh well. They’ll get over it.
Long-time readers of this blog already know that I’ve delayed starting salvage radiation therapy because I’m reluctant to incur the short- and long-term side effects of radiation without having a higher degree of confidence that we’re actually zapping in the correct location(s)—zapping the cancer itself.
Of course, the current state of imaging for prostate cancer generally sucks, but it is getting better with advances like PSMA PET scans using 68Ga-PSMA-11 where prostate cancer can be located much earlier and much more accurately than using previous technologies such as bone scans. But even 68Ga PSMA PET scans have their limitations.
One of the greatest challenges (gambles?) in deciding when to start salvage radiation therapy is the timing. Most will argue the earlier, the better. Statistics show that in most cases, the cancer is still in the prostate bed or pelvic region, so the radiation oncologists start blindly zapping those regions hoping the statistics are correct. But the cancer could have already spread to more remote locations.
With my PSA doubling time in the 4-5 year range, my team and I have decided to hold off on salvage radiation therapy and, in so doing, I’ve avoided any radiation side effects for five years giving me a high quality of life during that time. That has value to me. Of course, none of us know whether the little buggers have been hanging out in the prostate bed during that time (like statistics would show), or if they’ve gone on one of their own infamous road trips and have started spreading.
One of the things that I’ve been trying to determine for months now is at what PSA level can the Ga68 PSMA PET scan begin to reliably pick up prostate cancer. The answer typically was in the 1.0 to 2.0 range for the PSA. With a PSA a fraction of that (0.21) the PSMA PET scan really wouldn’t be a reliable tool for me yet. It’s not a completely worthless tool, but there are decent chances that I could come away with a false negative result.
The chart below taken from the paper was exactly what I was looking for and more. First, it shows the number of cases where patients with an increasing PSA after prostatectomy have positive results based on their PSA level. For those with PSAs less than 0.5 ng/ml (me), the number of positive cases was only 38%. In other words, there’s about a one in three chance that the Ga68 PSMA PET will be able to locate the cancer at that PSA level. Not good odds, but better than zero.
To me, the really interesting thing about this chart is that it shows the location of where the PSMA PET scan found the cancer by PSA level.
You can see that more than half of the cancer in patients with PSAs below 0.5 were found either in the prostate bed or pelvic region, both of which should be very treatable with salvage radiation therapy.
However, once the cancer is in other the other regions—extrapelvic nonbone (other organs), bone, or multiple regions—the cancer becomes very difficult if not impossible to treat. At that point, it’s only managed.
Please keep in mind that those are my non-expert opinions that I will have to confirm with my medical team to make sure I’m interpreting things correctly.
You can see that, as your PSA increases above 0.5 ng/ml, the cancer was found more broadly in the study participants. By that, I mean the cancer had spread beyond the prostate bed and pelvic region. You can also see, however, that even with PSAs less than 0.5, the cancer has already spread elsewhere in about 40% of the patients in the study with that PSA level.
That’s the whole point of knowing this. If the cancer has already spread, there’s no sense in zapping the prostate bed or pelvis risking long-term radiation side effects adversely impacting quality of life for no gain whatsoever.
This is only one study with 635 patients, so I am taking the results above with a healthy dose of skepticism, and I’ll continue to do more research in the three weeks before my appointment. But this study will be a good conversation opener for the consultation.
Some of the questions that are on the top of my bald head are:
Should we run another PSA test to see if this was an outlier/anomaly like some of my previous PSA tests (I’ve been using the same lab all along)?
How much weight does PSA doubling time have now that we’ve crossed the 0.2 ng/ml threshold?
Would he support getting the Ga68 PSMA PET scan done at this PSA level?
If not, at what PSA level would he support getting the PSMA PET scan?
Would he be willing to give me a referral to get one done even if I have to pay for it myself?
Fortunately, the US Food and Drug Administration approved the Ga68 PSMA PET scan at the University of California Los Angeles (UCLA), and that would be a 2.5-3 hour drive for me to get up there to have the scan.
In the meantime, I’m going to have to reconcile in my own mind how high I’m going to let my PSA get before taking action, scan or not.
Lots of research, thinking, and soul-searching ahead. But be forewarned: My trivial B.S. tolerance level is way less than my PSA. 🙂
A recent report in the CDC’s Morbidity and Mortality Weekly Report (MMWR) may offer one of the best analyses of an increasing risk for diagnosis with and death from advanced forms of prostate cancer over the period from 2003 to 2017 (the last year for which we have accurate data from the SEER database). There […]
Is it just me, or is anyone else having pandemic days all blend together and you lose track of time? Late last night (technically very early this morning as I was tossing and turning in bed around 2 a.m.), I realized, “Crap! I didn’t even think about posting on my blog, let alone write anything!”
So here I am on my advertised posting day with three hours and one minute left to get this out on the 11th, and I pretty much have nothing. Well, that’s not entirely true…
I did come across this article on The “New” Prostate Cancer Infolink that talks about PSA doubling times with respect to prostate cancer progression in men with non-metastatic castration resistant prostate cancer.
Unfortunately, they weren’t able to access the full study report, and the summary that’s provided is pretty high-level, restating the obvious: Shorter PSADT is associated with shorter metastasis-free survival and shorter overall survival.
One of the things that I discovered working in a hospital is that I can sometimes access research reports like this via its computer network. I’ll see if I can access this report to learn more details about the study and, if I can, I’ll share anything I learn.
Whew! Finished with time to spare. 🙂
Stay well and keep living the pandemic life as best and as safely you can wherever you happen to be.
Wow. I just may get this post out on time this month! I tell you, this pandemic thing has really thrown me for a loop when it comes to maintaining some sort of routine. Fortunately (or perhaps unfortunately), I’ve returned to working from the office every day for the last three weeks, and that’s brought some structure back to my life.
It’s hard to believe, but four months have passed since my last PSA test, and I’ll be heading off to the clinic on Tuesday morning. I hope. I haven’t actually confirmed that they’ve reopened for routine things like blood tests. If they are open and they do take the sample, I should have the results late Thursday night or Friday. My appointment to go over the results is on 2 July.
Just as a reminder, here’s my PSA roller coaster:
I’m at the point where I don’t get too worked up about these tests anymore, even with the upward trend. It is what it is and I’ll deal with the number when I get it.
Imaging Trial for Veterans in Los Angeles
The VA Greater Los Angeles Healthcare System is conducting a phase II trial “to determine whether a positron emission tomography (PET)/computed tomography (CT) scan using 18F-DCFPyL affects the clinical management plan in Veterans.” Some are saying that 18F-DCFPyL may prove to be even better than a Ga-68 scan.
For patients with biochemical recurrence, they want your PSA to be at least 0.2 in a post-radical prostatectomy situation, so unless my PSA jumps up again next week, I’m not eligible. (No, I’m not wanting it to jump up.) The cost is free to veterans and only veterans are eligible. You can learn more about the trial here:
My interpretation of the paper with my specific numbers kind of reinforces what the doctor told me at my last visit: that I’m okay continuing to watch my PSA for now. Others with different numbers may come to a different conclusion. We’re all unique, after all.
I’m scheduled for my next follow-up with the doctor the first week of July, so I’ll have to get my blood drawn for the PSA test in late June, assuming the COVID restrictions are lifted by then.
You may recall my last post where I talked about taking medication to lessen the nerve pain in my leg. I started the medication on 30 March 2020 and I seemed to hit the side effects jackpot. They knocked me for a loop, at least initially (hence, no writing).
Headaches, dry mouth, nausea, diarrhea, and extreme fatigue plagued me the first two weeks, but the good news was that the nerve pain was reduced a good 50% to 70%. The side effects were so troubling in the first few weeks that, by the middle of the third week, I cut the dose in half, but the nerve pain returned.
I’m back on the full dose now, and my body seems to have adapted to a degree. The fatigue is still present, the dry mouth is still there, and the nausea is very mild and only early in the morning. (No, I’m not pregnant.) The pendulum swung in the complete opposite direction on my GI system–constipation is now the norm. Sorry. I’m oversharing once again.
We did discuss physical therapy as part of my treatment plan, but that was just as COVID was rearing its head, so that’s been put on hold for now.
I had been fortunate enough to be able to work from home since 16 March because of COVID-19, but I’ve returned to work in the office at the hospital beginning last week.
On the whole, I’m pretty comfortable being in the office again. Sure, there’s a more risk than just sitting at home, but my office is well away from a high-traffic area of the hospital and I’m literally the only person here. I don’t have to go into any of the wards, and the walk from my office to the exit is relatively short. I probably feel more at risk in the grocery store.
California was one of the first states to impose a stay-at-home order and we’re being very cautious and deliberate in our re-opening. Some will say that we’re being too slow, but not me. Our efforts really did make an impact on controlling the virus. We’ve got nearly 40 million people in the state and we have just over 80,000 positive cases and 3,240 deaths. Contrast that with New York state with 19.5 million residents with over 351,000 positive cases and 28,339 deaths.
No matter how you slice it, though, it’s universally tragic. We’re all anxious to get this under control and behind us.
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.
One of the cool things about working in a hospital is that I can access full versions of some of the scholarly articles on prostate cancer that are normally blocked to the public by their publishers. At the end of the day today, I pulled the full versions of each of these articles for a little light bedtime reading about salvage radiation therapy, toxicities, and imaging:
I skimmed a couple of them on the bus ride home this evening (as much as you can skim on a bouncing bus), and I’ll go through each in a little more detail before my appointment a week from tomorrow.
When I pull articles like this, I consider a few things when reading them:
When was the article published? Obviously, more recent is generally better, although you can’t discount data from earlier studies entirely.
What type of research was done? Was it a retrospective study of historical medical records or was it a full-blown trial?
How many patients were included in the study? Fewer patients (<100) may yield less reliable results than those that include several thousand.
Over what time period did the study look at patients? Studies that looked at records from the 1990’s into the early 2000’s will reflect the treatment options and technologies available at that time. Studies done more recently will reflect the impact of newer treatment options and technologies.
Who conducted or funded the study?Who’s conducting a study and how it’s paid for could, in theory, perhaps skew the results (e.g., Big Pharma wanting to push a new drug).
So I’ll be going through each article, gleaning whatever I think may be of value for the appointment, adding to my list of questions to be asked.
Please don’t ask me to share the full versions of the articles here or elsewhere. Not only am I cancer-averse, I’m litigation averse. I’m not keen on a copyright infringement lawsuit because I posted something on this blog/website that I didn’t have permission to do. 🙂
That said, I may try to summarize some of the findings in future posts, with full attribution of any quotes, of course.
Here’s an interesting trial with surprising results.
Data from a recently published, Canadian, clinical trial of high-dose vitamin D as a method to strengthen bones in healthy adults who do not have osteoporosis have had significant and unexpectedly negative results.