Prostox - learn about whether radiation will cause problems

Thanks Jeff for this update.

We asked RO about this test for salvage RT and he replied that Prostox is useful only for primary therapy. We knew that it is not the case but one can not argue with RO without having "black on white" proof for the argument.

We tried to contact UCLA for the info with no luck and I contacted Prostox and got very vague answers - not definitive "YES , it can be used for salvage" and how. I just got a link for a "poster" from some presentation, so no help there either.

So yes, if you would be so kind to ask that question it would be wonderful - how is Prostox used in planning salvage RT. Of course it can help with choice between SBRT and IMRT , but would it have any value for patient who would have IMRT ? Would it help with planing or it has no value since IMRT is going to happen so good luck with SA.

Thanks for the invite for AnCan - unfortunately due to privacy issues it can not happen.

Thanks so much in advance < 3

The ProsTox test helps to assess delayed side effects especially urinary for the varieties of photon external beam therapy. Acute immediate side effects are the same for them and disappear about the same time. Delayed symptoms occur months to years later. I suspect they are looking at other data and may have expanded its value. The AnCan talk on 27 April 1900-1955 EDST should be very interesting.

It seems Go To meeting costs $. Is that right?

@climateguy
GoTo Meeting is free to download and install on all platforms. I’ve been using it for many years never paid a penny. The people that hold meetings with it are the ones that pay for the Services.

@surftohealth88 If your choice is RP vs IMRT vs SBRT the Prostox test can help you avoid late side effects by choosing a primary treatment with less probability. If you are locked into IMRT or SBRT as the only treatment it will just increase your worry and apprehension if it comes back with high risk. If you have a choice between IMRT and SBRT it is still valuable since less than 15% of those that test high risk do so on both the IMRT and the SBRT tests.

Just need to give people a heads-up. Because my husband has a weak stream and a 3+4 tumour in the right medial apex, we were worried that radiation could convert his existing weak stream into no-stream-at-all.

So we ordered both Prostox Ultra (SBRT) and Prostox Standard (CFRT) tests. Only 1%–2% of patients are found to be high risk of toxicity from both SBRT and CFRT/MHFRT. He scored "HIGH RISK" on both! Radiation was out!

Pic 1 👇 shows what our January 15, 2026 Prostox report looked like. It had just two risk categories. Either "LOW RISK" or "HIGH RISK".

I checked today and UCLA/Prostox has now changed their "Interpreting PROSTOX Results" report page to "LOW-AVERAGE RISK" or "HIGH RISK"!
https://miradx.com/prostox/interpreting-results/
From "LOW RISK" Jan 2026 to "LOW-AVERAGE RISK" now...

I wonder if page 2 of their current results report still includes:

"Limitations: Results do not predict a patient’s likelihood of clinical response, short-term side effects, or non-urinary side effects from SBRT or CFRT. A low-risk result does not rule out any possibility that the patient will experience toxicity, and a high-risk result does not guarantee that the patient will develop toxicity. Results should only be used as part of the
consideration of treatment choice."

@jim18
Thanks so much for your input. That is the whole problem - I read that Prostox is valuable for salvage therapy and one of the members was told that by dr. Kishan himself, so I am confused why our RO refused doing that test and how is Prostox valuable for salvage therapy (because it supposedly IS). Perhaps it helps with planing of how many sessions and what amount of total radiation should be administered for the least possible damage ??? I would really like to know definite answer and I did not get it even after contacting Prostox.

@surftohealth88 Was any germline gene testing done? Many of the genes that Prostox looks at are involved in DNA repair and associated with cancer risk. If no cancer related genes such as BRACA1/2, ATM, etc. than less likely to have high score on Prostox. Do you want to take a higher risk of a second recurrence to reduce the probability of radiation side effects? Can always get someone to order the test self-pay (was about $395).

@jim18
If needed my husband will have salvage, that is not even a question ; ).
It is about planning RT - how many sessions and how many Gys total.

I know that with IMRT one can have more sessions with lower radiation or less sessions with more radiation administered at each visit and both protocols would yield absolutely same end results, BUT more sessions with less Gys would produce less AS. So- IMHO having Prostox would help with planning.

My husband had genetic testing - he has no inherited mutations of any kind, so thanks for sharing this information < 3. I did not know that it can predict sensitivity too. Very comforting to know . THANKS

PS: We were told that only doctor can order test - we can not order it ourselves or we would have done it long time ago .

@jim18
You should attend the Prostox meeting on the 27th. This is a question you should address the speaker with. Not sure what you’re saying is really the whole story. So a few people have genetic problems that the test itself can’t really be all that dependent upon them.