All the radiation based treatments will be similar in that it takes anywhere from two to five years to reach the nadir. Also many men will experience the PSA bounce in the 18-36 month range. Each man will be unique as to the process and time of these events so all we have are general guideline.

What you are after is continual decrease and a nadir of .50 or less. Then if there is an increase you have a PSA margin if nadir + 2.0 before it is determined the cancer is still growing. This can happen very soon if a significant amount of PCA was outside if the radiation field, or after many years if just a little was already out or stays dormant. For most it will never happen because of the initial treatment success rate of radiation. There are reports of men having long term undetectable or very low stable PSA that have recurrence 10-15 years after initial treatment whether they had surgery or radiation as the initial treatment

The initial PSA drop shows the early effect of some of the cells dying due to the radiation itself. But most of the cells don’t initially die but the dna is irreparably damaged. These cells will continue to live and express PSA but can not divide. thus they can’t grow or spread. Eventually these will die as well but not on any set schedule. The theory of the bounce is that a lot of cells die st the same time and give off more PSA at once. If this doesn’t happen it means the cells are dying on their own gradually over a period of time.

The primary reason that PCa exhibits this slow death and many other cancers show more immediate results is that the prostate cell is one of the longest living cells in the body. Many cells in our body have lives measured in days or weeks where the prostate cells can live a year or more before their planned death (apoptosis). Thus the PCa cell retains this feature and is generally long lived. This feature appears also to be among the reasons that most PCa is most often slow growing and more indolent than most other cancers.

The initial radiation beam doesn’t kill many cells during the radiation. But it damages the DNA. The PCa cells cant self repair and eventually die. The healthy cells suffer DNA damage from the radiation, but most are able to self repair and continue to contribute to a functioning prostate. Those that can not repair die and are flushed from the body through the lymphatic system. However, the change is such that they will never express the same level of PSA that an unradiated prostate expresses.

Cancer cells are most vulnerable to damage when dividing. This is why most chemotherapy is done in several doses over many weeks or months. This improves the odds of subjecting all the cells to the chemo at the appropriate time. That is also why chemo isn’t very effective with PCa. At any given time, very few cells are vulnerable.

As to the radiotherapy it has been shown that PCa is more susceptible to large doses of radiation. Thus HDRBT and SBRT external beam are stronger cancer killers than permanent seeds and the traditional radiation fractions.

Both PCa and breast cancer cells can also go dormant for years, usually located in the ends of bones. While dormant PCa cells express no PSA. At some future time something happens to awaken them and they start their living, expressing PSA and can cause damage. That is one reason many men can be undetectable for years then have a recurrence. Same with breast cancer. One of my clients had a recurrence eleven years after what appeared to be successful successful treatment for breast cancer. Another client had a RP at age 55 and 16 years of undetectable PSA and then a recurrence that prompted ADT for control.

Denis,
I'm at 6 years and still decreasing. There are 5 or 6 other radiation patients on this site that has taken 5 years or more to reach nadir.

Paul

Paul thanks knowing what others have experienced is helpful. Denis

My latest PSA, just last week, was 0.20 and that was a drop from 0.27 three months earlier. I'm taking a T replacement therapy so I'm getting checked pretty frequently. So I'm at 3.5 years and still seeing a drop.

Got a digital exam last week as well and it checked out good as well.

In my case I am still trending down as I near three yrs post treatment, with one early bounce. From the posts of others who have had HDR my numbers and trend look pretty typical. Which doesn't mean it's a problem if your experience is different. See TA's recent post about multiple bounces and how that may be a good thing.

Actually not Sr Sailor.

At least tens of thousands of men have used HDRBT since 1981, so there is a lot of good evidence available. I have never read where the PSA post treatment progression or bounce is any different based on the type of initial radiation treatment.

The reason the trends are variable is because each man and his cancer and its response to treatment is unique and different. No two men are the same and no two cancers are the same, so how can we expect all to respond in a similar fashion?

Subdenis, I'm not sure how appropriate my situation was since I was on ADT after my brachy, which kept my PSA artificially low. (I also had combo therapy with IMRT.) My ADT finished about a year after my radiation and ever since my PSA has ranged from 0.2 to its current 0.09. Trend has been down, although the band is so narrow I'm not sure it matters.