Hello Robins,
   I would figure what the number you currently have, and or had, and if it
is rising in comparison from that number then I would concern myself with
more evaluation.
The number, and when it starts to raise is the concern.  When it starts
climbing, just as with RP patients or seed patients, or radiation patients,
then evaluation should be considered.
I wish you well, and hope your PSA number always is low, and dropping.  John
Loomis, getting my 4th year PSA test in the next week.  Good wishes.

The radiation oncologist who is treating me said the PSA should
drop to below 1.0 and stay there.  She said that although some
men get an undetectable PSA, that is uncommon.  She said
there will still be a prostate and it is likely it will still produce
some PSA.

I haven't yet gotten her opinion on _when_ the PSA should
drop to that level.  It is my understanding that the prostate cells
are badly stressed by radiation and put out PSA as a consequence
for some time after radiation ends.  She thought the first PSA
test that was meaningful at all would be at 3 months, but my
understanding is that 3 months is not likely to be the "nadir".
In most men, PSA would continue to fall after that and the
nadir, or low point could occur a year or more after the
end of treatment.

I presume that hormone therapy complicates this picture since
it, by itself, causes PSA to drop.  Furthermore, the reaction
to HT varies greatly from individual to individual.  The doctors
may prescribe an injection every 3 months, but that doesn't
mean that at the end of 3 months the Lupron, or whatever,
is out of your system.  I was told that 6-9 months is a more
realistic number and that some men feel effects for a year.
Based on my reading, it appears that some men may have
lowered PSA for significantly longer than that caused by
the HT alone - independently of the success of the RT..

As a an RT + HT patient myself, I am very curious to learn
what other patients have been told.  If you have some info,
please do post it.  My RT will end on Jan. 21, and my
last HT injection (22.5mg Lupron) was in late November.

   Alan

Just be aware that PSA doesn't always go straight down.  Similar to
SI+EBRT, EBRT alone can bounce around.  Her's a couple of articles
describing the EBRT bounce studies...Best wishes and good health, Ron

J Urol. 2002 Nov;168(5):2001-5.
Prostate specific antigen bounce phenomenon after external beam
radiation for clinically localized prostate cancer.

Rosser CJ, Kuban DA, Levy LB, Chichakli R, Pollack A, Lee AK, Pisters
LL.

Department of Urology, The University of Texas, M.D. Anderson Cancer
Center, Houston 77030, USA.

PURPOSE: We characterize the prostate-specific antigen (PSA) bounce in
patients who underwent external beam radiation therapy for prostate
cancer and correlate the PSA bounce with the development of
biochemical disease progression. MATERIALS AND METHODS: In this study
964 patients received full dose radiation therapy alone. Followup PSA
values were obtained 3 months after completion of radiotherapy and
every 3 to 6 months thereafter. Median followup of the entire study
group was 48 months. All time intervals were calculated from the
completion date of radiation therapy. PSA bounce was defined as an
initial increase in serum PSA of at least 0.5 ng./ml., followed by a
decrease to pre-bounce baseline serum PSA values no more than 60
months after external beam radiation therapy. RESULTS: Of the 964
patients 119 (12%) had a PSA bounce. PSA bounce was unrelated to age,
race, pretreatment PSA, Gleason score, clinical T stage or radiation
dose. Mean time to PSA bounce was 9 months from the time of therapy.
The respective 1 and 5-year biochemical disease-free survival rates
were 100% and 82.1% for patients with PSA bounce and 93.9% and 57.7%
for those without PSA bounce (p = 0.0001). CONCLUSIONS: Of men with
prostate cancer treated with external beam radiation therapy 12%
experienced a transient increase in PSA (PSA bounce) followed by a
return to pre-bounce levels after radiation. The PSA bounce phenomenon
was not predictive of time to biochemical recurrence.
PMID: 12394695 [PubMed - indexed for MEDLINE]

Int J Radiat Oncol Biol Phys. 2001 Jul 15;50(4):845
Patterns and fate of PSA bouncing following 3D-CRT.

Hanlon AL, Pinover WH, Horwitz EM, Hanks GE.

Department of Biostatistics, Fox Chase Cancer Center, Philadelphia, PA
19111, USA. AL_Hanlon@FCCC.edu

PURPOSE: The goals of this study were to quantify the frequency of
post-treatment prostate-specific antigen (PSA)-level bouncing
following three-dimensional conformal radiation therapy (3D-CRT) for
prostate cancer and to identify any relationships that may exist
between bouncing activity and biochemical control (bNED). METHODS:
Between May 1989 and July 1995, 306 patients were treated with 3D-CRT
alone. All patients had 6 or more post-treatment PSA levels and at
least 5 years of PSA follow-up. The median total follow-up and total
dose to the center of prostate was 79 months and 74 Gy, respectively.
A bounce was defined by a minimum rise in PSA of 0.4 ng/mL over a
6-month period, followed by a drop in PSA of any magnitude. Estimates
of bNED control rates were made using Kaplan-Meier methodology and
comparisons were made using the log-rank test. Multivariate analysis
of bNED control predictors was accomplished using a stepwise Cox
proportional hazards model. RESULTS: Nearly one third of the patients
experienced at least one bounce. Bouncers were found to present with
higher pretreatment PSA levels and were treated with lower dose levels
to the center of prostate. Five-year bNED control estimates for
nonbouncers vs. bouncers were 69% and 52%, respectively (p = 0.0024).
After controlling for dose and pretreatment PSA level, total number of
bounces emerged as a significant predictor of bNED control (p = 0.02).
CONCLUSIONS: Bouncing PSA levels occur in approximately one third of
the patients treated with 3D-CRT alone, with bouncing occurring at a
constant rate from 2 to 5 years post-treatment. Bouncing is associated
with lower radiation dose levels, higher pretreatment PSA levels, and
decreased bNED control. Nearly half of the bouncers are bNED
controlled; thus, clinicians should not use bouncing as a sole
indicator of relapse.
PMID: 11429210 [PubMed - indexed for MEDLINE]

After radiation, the cancer cells take a while to die, so the PSA gradually
drops over the next year or two.  It usually does not go to "undectable", ie,
less than 0.1 but something like 0.5 to 2.0, called the "nadir".  You check
every three to six months for a few years and if it starts going up again, you
have more work to do.

Hard to say, exactly, but as it was described to me by my onc, with
radiation, you want the PSA to go down steadily and level out about .1 or
less than .1.  It may take two years to do that.  And if it levels out for
30 years, you're cured.

However, HT should take it down immediately to below .1 and stay there until
it become refractive.

In any circumstance, if the PSA rises once, it is something to be curious
about, but if it raises again, it is something to be concerned about.