Practice Updates in Prostate Cancer Imaging - Episode 6
Doctors present the patient profile of a 66-year-old man with high-risk localized prostate cancer.
Michael Gorin, MD: The first patient today is a man who's aged 66 years and at the time of his first prostate cancer screening was found to have an elevated PSA [prostate-specific antigen] level to 16.5. He has no history of any urinary complaints and no family history of prostate cancer. His performance status is excellent. He has little in the way of medical comorbidities. A repeat PSA was performed, and it was found to be 18.2. On rectal exam, there was an area of induration in the left posterior aspect of the prostate and so based on this PSA elevation and this concerning rectal exam. A transperineal prostate biopsy was performed demonstrating, grade group 4 prostate cancer in multiple cores. This patient expressed interest in undergoing radical prostatectomy but was also of course counseled regarding other potential treatment options such as trust's radiation therapy. But of course, prior to being able to commit to one of these 2 treatments, per the current guidelines from the NCCN, [National Comprehensive Cancer Network] he requires staging imaging to figure out whether or not his disease is localized to the prostate only or perhaps he has some other sites of disease.
Neal Shore, MD, FACS: Here we have a potential tumor board discussion having someone who has high-risk disease, elevated PSA grade group 4, and what would potentially be? Prior to PSMA PET, what would you do? How would you work up this patient, Steven?
Steven Finkelstein, MD, DABR, FACRO: This case hits home. For many of you know, my father was diagnosed with high-risk prostate cancer like this. And when you have a case like this, you want to get a good test to see if a person had metastatic disease. Classically, as the classic D'Amico risk got more, we got imaging and that was either a CT or an MRI of the pelvis to look locally. And we got a bone scan which was a technetium 99 bone scan. And those tests were just not as robust as we wanted especially the technetium 99 bone scan but 10 years ago, when my father was diagnosed with this, what I would have wanted was could we have done an imaging modality with PET scan if it existed. That could find sites of disease both in the prostate and… outside the prostate either in the regional nodes or distant disease. Now, PSMA imaging that is available, next-generation imaging that is available to be able to stage patients with high-risk disease. To see where they truly stand.
Neal Shore, MD, FACS: Having said that Steven, here is the risk stratification staging workup of clinically localized disease from the NCCN. And what you see here and there has been some recent modifications to this and let me have your thoughts on this. Healthy 66-year-old [man], grade group 4 high-risk disease. He sounds like he's at least T2b and prior to PSMA pet. Are you comfortable with the stratification and the imaging that's suggested here?
Steven Finkelstein, MD, DABR, FACRO: You have to go back to the past. Classically we used D'Amicostaging and that was low intermediate and high. Broke up by eventually via NCCN guidelines and then other guidelines that adopted this. We got here where we broke up each individual group, low into low and very low, high into high and very high, and intermediate into favorable and unfavorable. And we knew as when we scanned lots of low-risk patients, we never found a lot of patients with that disease. And it just didn't seem like imaging would be something that could help when we had bone scans with technetium 99. Now we also knew that as you had high-risk disease patients despite our best work as radiation-oncologists or surgeons, surgeons, or radiation oncologists. About 1 in 3 patients who undergo therapy in the high-risk setting will ultimately have that therapy fail them. And when we do that, you'd like to know if that person had either regional or distant disease and we just never had the ability to do it. When you look here, the ability to get good imaging probably is most robust as the disease risk goes higher. Now very high and then the high and then the unfavorable intermediate risk. And very low, low, and favorable intermediate risk, you probably have less a chance of finding distant disease but that's not necessarily bad. It reassures a patient that they don't have disease outside of the definitive side in the prostate. Plus, for radiation-oncologists, we can use that imaging in treatment planning to put the hot spot in radiation therapy in that dominant nodule or multiple dominant nodules. And for the first time, next-generation imaging may be very useful across a spectrum of different risk groups.
Neal Shore, MD, FACS: Those are nice summary. And when we look at this now, Larry, here's some of the updating that we've seen here as it relates to the ability now to order a Gallium or a fluorinated PSMA PET. There’s increased sensitivity, and the specificity. Now at Yale, for this type, for this patient that Michael has presented, the high risk clinically localized, what's the standard of care right now or what are you recommending and how do you think about this information?
Lawrence Saperstein, MD: Great question. As you alluded to the updated guidelines are somewhat open-ended and give us the ability to use this advanced imaging more readily than before. And in these patients, we would do PSMA PET CT for staging as a first-line. The question would be as the experience evolves and I would—to the other panel members is the feeling that urologists and radiation oncologists are willing to embrace this as a first-line imaging in patients of this high risk or even intermediate risk. I think that's the ultimate question.
Transcript edited for clarity.