Maybe Tall Allen can comment on this study.
I've seen a number of similar studies. The most important line is the last one: "Multicenter prospective studies with a control group are needed."
In other words, they chose the patients to receive salvage ePLND for a reason - they may have thought they were light cases that might have some response. Did they respond? Certainly, there was a local
response and that source of PSA was removed. But treating PSA is not the same as treating the cancer. Was overall survival increased by this radical treatment? It's hard to say. What would these patient's survival have been if they did not receive this treatment? All indications are that spread via the pelvic LNs goes very slowly at first anyway. Here's an article about
the dangers of misinterpreting these kinds of studies./pcnrv.blogspot.com/2017/05/unwarranted-conclusions-about.html
It is not surprising that getting rid of the oldest detectable metastases will "restore" ADT sensitivity. I put "restore" in quotes because a common misunderstanding about
castration resistance is that ADT sensitivity is totally lost - it isn't. There are always some population of cells that will be killed or suppressed by ADT. That's why Lupron is always continued when second-line hormonals are layered in. The important question, which is unanswered in this study, is whether that had any effect in delaying progression and extending survival.
Given those caveats, I think that there probably is a benefit to whole pelvic radiation, and possibly ePLND, after cancerous LNs have been detected. Here's a recent article on the subject of salvage whole pelvic radiation treatment after pathological detection:/pcnrv.blogspot.com/2017/12/salvage-whole-pelvic-radiation-after.html
Detection is a big issue. Even our best PSMA-based PET scans are not very good at finding them. There is a size limit of about
4 mm, and they have to be PSMA-avid. A USPIO MRI (available only in Holland) can bring the size limit down to 2 mm. But even that does not detect them all. There may be tens of thousands of cancer cells in a detectable met, and thousands in a non-detectable met, and many more in systemic circulation. What we can detect is a fraction of what may be there.
open question is whether salvage ePLND or salvage pelvic RT is more useful. The problem with even the most scrupulous ePLND is that it will not extract all the potentially cancerous pelvic LNs from the area. The problem with salvage pelvic RT is that the dose (usually around 50 Gy) may be inadequate to kill all the cancer in the area (which is why adding ADT is important). Recently we learned that the pelvic treatment area for both ePLND and RT has been inadequate. There is also the danger of toxicity, especially with ePLND - lymphocele and lymphedema can be crippling. So we really want to be sure that it accomplishes something oncologically before it is attempted.
The alternative is picking off the detected metastases with SBRT as they are found ("whack-a-mole"). No one knows if this accomplishes anything either. The best evidence so far comes from a small Belgian study, and the results are equivocal. They found that it extended the time until ADT was required by 8 months. But
the control group had to have just one more detected met before ADT was required, whereas the treatment group had to evince 3 additional mets simultaneously
before ADT was required, and
they had to stretch the conventional confidence interval for statistical significance to make that claim./pcnrv.blogspot.com/2017/12/metastasis-directed-therapy-for.html
measure up to 1.56 SUV and does not appear to be pathologic activity.
Your radiologist is correct. SUVmax under 2.5 is benign.
Allen - not an MD
•PSA=7.3, prostate volume=55cc, 8/17 cores G6 5-35% involvement
•SBRT 9 yr onc. results
•SBRT 7 yr QOL results
•treated 10/2010 at age 57 at UCLA,PSA now: 0.1,no lasting urinary, rectal or sexual SEsmy PC blog
Post Edited (Tall Allen) : 1/13/2018 8:11:57 PM (GMT-7)