Importance of <.50 Nadir

Reaching a nadir of <.50 following primary RT appears to offer a significantly better chance of not relapsing than men with a nadir >.50. What is the likely physiology behind that? Is this still current thinking?

Yes, I have seen that many times as a guideline. Of course the lower the nadir the better, but the expected nadir is higher for radiation than surgery.

I understand that <.50 is sufficient as a post-radiation nadir because the prostate is still intact and probably expressing some small amount of PSA. Radiation affects the DNA of the healthy cells and most self correct most of the damage. But the radiated prostate never again expresses what would be a normal PSA of a non-radiated prostate.

If the nadir was a higher number and remained stable under nadir+ 2.0 then it would continue to indicate a remission of the cancer. Above that measurement it would indicate a recurrence of the cancer and could warrant additional treatment.

Your information regarding Dr. Critz is basically correct. He pioneered the use of brachytherapy and external beam together rather than applying them sequentially. His theory is that by applying the external beam while the seeds are active there is a complimentary effect that is more effective than either by themselves. This has proven to be correct as prostate cancer is more sensitive to higher radiation doses than many other cancers. For intermediate and high risk this has become the norm. tall Allen refers to this as “brachytherapy boost”. For lower risk, it is too much radiation and not necessary. Thus the brachytherapy mono-treatment has become much more popular for low risk men and is less toxic. Some of the docs in the practice that Critz founded will use mono-therapy brachytherapy on low risk.

If you read the website he clearly states that from the beginning in the 1970’s he wanted to measure his treatment efficacy against surgery. The urological definition of surgical success is stable PSA at or below .20. Thus, he uses that same standard. In his website information he also shows that the ASTRO definition of cure is stable PSA of 2.0 or less. So there is no confusion here and your doctor simply didn’t do a thorough read of Critz’s information. He basically went up against Walsh to show that radiation therapy was as effective or more so than surgery and his published results have confirmed that.

Critz has been publishing treatment results for Probably 30 years or more. I believe was the first to publish 15 year results on a peer reviewed basis. This was in the late 1990s. When I was diagnosed I consulted with him and was favorably impressed. I also attended a dinner that he holds monthly that includes patients he has treated and prospective patients. This was very well done and valuable to me. One of his radiation oncologists was treating my wife with a very tricky breast cancer radiation therapy that most oncologists said couldn’t be done since she had already had full breast radiation for a prior occurrence. He did it successfully nearly eight years ago and she has done wonderfully well. I ended up using HDRBT as my research showed advantages to the procedure and I had two excellent HDRBT clinics in Atlanta to choose from. Had I not used HDRBT I am confident I would have done very well with Critz. I have a business partner that was treated by him nearly 20 years ago and several clients that have used his clinic. All are doing well and pleased with their choice.

I explained the tactics in the combined radiation method Critz uses. As we all know different doctors have different tactics within the same treatment method. Sylvester and others show that. Often, there are no discernible differences in the results. But when there are difference most doctors will change their tactics to try to get better results.

Does Sylvester publish his long term results on a peer reviewed basis?