PSA change from < .04 to < 0.1: Problem or no big deal?

I personally would want to have my PSA tested every 3 months if it hit .1 After radiation. This may or may not be an issue. Sometimes the PSA can bounce around a little yours is just a little more than double, How long a period of time between PSA tests? The standard for having treatment after having your initial radiation prostate cancer treatment Is that you wait until your PSA hits two points above the minimum, which would be 2.04. There’s actually no reason to wait that long at 1.04 you could get a PSMA pet test to see if there is a metastasis found somewhere causing this PSA rise. If there is, it can be a zapped with SBRT radiation.

This is something you should discuss with a medical oncologist And a radiation oncologist. If your PSA continues to rise.

Unlikely following a prostatectomy where PSA is expected to remain undetectable going forward, following radiation once the ADT leaves the system, PSA is expected to increase to a “new normal” level since a healthy prostate remains.

The goal is to be at < 0.2 following treatment, establish a PSA nadir, and then a small increase from there is expected. Technically, biochemical recurrence is when PSA reaches nadir+2.0. But, you’re nowhere near that.

Nothing serious to worry about for now, just keep tracking PSA.

(I’ve attached my post-radiation treatment PSA results.)

You are still under ADT so your PSA should stay < =o.1
You are just under 1 year from the end of radiation so that is still in the process of killing cancer. You should definitely start checking your PSA every 3 months. Ultimately when your ADT period ends then a PSA well above 0.1 is ok. But while under ADT your PSA should stay very low. Let us know what your RO thinks about your current PSA.

Four months since my last PSA test in November 2025. Can a change from < .04 to < 0.1 be possibly due to the sensitivity of the test being done by the lab?

@johnny8924
Was the test done in the same lab?

Was an Ultra sensitive test done. If not ultra sensitive then the highest rating is < .1

To get a reading of .04 you must have an ultra sensitive test.

Is it possible the test was different? If so, then the change is irrelevant.

@jeffmarc
Thanks for your comments.
Done by the same lab.

@johnny8924
Ask the lab if the < .1 was ultra sensitive. The .04 is.

I see you had IMRT. I was wondering is there any big reason to choose IMRT vs SBRT Vs I think there is some proton beam out now. I know KUMC has a building called the Proton Center. Anyway my question is there anyplace that explains pro and cons of the various radiation treatments?
I am still thinking cut the blasted thing out and be done with it, but haven't talked to RO or surgical doctor yet, that comes Monday.

@johnny8924 -- I've also used a single lab and had exactly the same difference in results at different times (ie. "< .1" and ",.04"). In my case, I got a (free) user account on the lab's web site and was able to print a "report" of each test. That report allowed me to see that they had used different types of machine (with different sensitivity) to measure the psa. I know the doctor orders for the psa test were identical, but I suspect the lab just used the more sensitive test for their convenience. I believe with the "< .04" and "< .1", the "< " symbol is indicating that the psa was unmeasurable on that machine. All that said, it never hurts to discuss it with your doctor or the lab. Best wishes.

@diverjer
According to radiation oncologist that do SBRT, the higher amount of radiation used with that technique does a lot more damage to the cells and is more effective.

IMRT also works if you need Lower dose radiation over more sessions.

A Prostox Test can be done to see if your system can handle SBRT or is IMRT better for you.

Proton radiation has the ability to just target the cells that need to be targeted and avoid the other others. It is used on brain tumors that children have so that they can only have the cells that need to be radiated done, Leaving the rest of the brain undamaged.

If you watch the 2023 PCRI Video and see Dr. Carl Rossi talking about radiation you find some interesting things. For one he’s been doing Proton radiation treatments since 1994 when they built a building for the machine in San Diego. The first patient was the person that invented it, He lived to over 100. He has done Proton radiation on over 13,000 prostate cancer patients.
That video link is

The question with proton therapy is how long will you live? For somebody in their 60s desiring to live Another 20-40 years, it’s nice not to worry about secondary cancers. For somebody who is 75 the risk of a secondary cancer is very low so the lesser expensive therapies make more sense, or do they.
While we’re talking about it, here’s some info about the secondary Cancer risk of different types of radiation.
Studies suggest that SBRT may be associated with a lower risk of developing a second malignancy compared to other radiation modalities like conventionally fractionated intensity-modulated radiotherapy (CF-IMRT) and brachytherapy (BT), according to ScienceDirect.com. Another study found that SBRT's probability of causing secondary cancers was similar to that of radical prostatectomy (surgery), according to ScienceDirect.com.