How do you know if radiation treatment worked?

[Mgtd]

I had 25 sessions of radiation to prostate and pelvic area as a precaution and 6 (2 months prior and 4 after radiation)months of Lupron. For 9 months post radiation PSA has been not been detectable and it has now risen to 0.04. T is in the normal range. All other blood works were normal.

Meet with my medical oncologist’s PA last week and she said it was not an issue. Just trying to confirm that.

Prior to radiation I was Gleason 7 (4+3) high level of core involvement. Just had old style testing. No fancy scans. MRI said it was confined. Very minor issues with radiation and Lupron. Great health, soon to be 79 and do resistance training daily and walk every day. Average 5.5 to 7.5 miles per day. Reasonable diet.

How do they determine that radiation has failed? About how long does radiation continue working?

[Justfor_]

It takes 2+ years to learn.

[Mgtd in reply to Justfor_]

Thanks! Really appreciate the reply.

[Tall_Allen]

Biochemical failure is your nadir PSA +2.0. If it gets up that high, they may want to investigate. It took me about 31/2 years to reach my nadir (where it has held for 10 years).

[Jewelrylady in reply to Tall_Allen]

Is nadir the lowest your PSA ever got? I’m not sure what it means.

[Mgtd in reply to Jewelrylady]

PSA nadir is in fact just that. It is the lowest it reaches say after radiation in my case. In general the lower the nadir and the length of time to reach that nadir the better it is for a prognosis.

Since after radiation as the primary treatment that is the best indication that guides further treatment. It is my understanding that post treatment PSA is a very good measurement unlike the questionable impact it can have before.

I am sure others will give a more exact definition but that in laymen terms is what a nadir is and its use after treatment.

[Tall_Allen in reply to Jewelrylady]

Yes. Lowest to date.

[Mgtd]

OK! Hopefully it looks it will be a while. Thanks

[vintage42]

Radiation failure is assumed if the PSA rises too much after reaching a nadir. My nadir was only 0.93 and then after 2 years the PSA rose up to 5.71. A PSMA-PET scan showed cancer remaining in the prostate and spread to a node.

I don't know if my failure was caused by poor IMRT technique (targeting, dosage), my cells being "radioresistant", or my not using ADT until after the failure had occurred.

As to how long radiation "works", some cancer cells get killed, some can be resistant and survive, and some may be out of the target and are missed. And some good cells can catch a little radiation and take years for the effect to be noticed.

Late Radiation Cystitis of the bladder used to be more common in the earlier days of radiation, often not appearing for years.

[Mgtd in reply to vintage42]

Hoping that the SpaceOAR did a good job of eliminating that issue.

[vintage42 in reply to Mgtd]

SpaceOAR is for the rectum. I did not have it, and had no problems there.

[Mgtd in reply to vintage42]

I need to look up radiation cystitis. I thought it was associated with the bladder. Learned something new already and the day just started.

[Mgtd in reply to Mgtd]

Well I did some research and found out more about it. Since I had my pelvic area done as a precaution I have a 5 to 10 percent Chance of having this. Thanks for the heads up and for leading me to understand what it is.

[vintage42 in reply to Mgtd]

Radiation can cause proctitis of the rectum and cystitis of the bladder.

Prostate radiation in 2021 and pelvis radiation in 2023 caused neither proctitis nor cystitis.

[bobdc6]

I finished proton in August of 2017, my latest PSA was .09, doc said no problem.

So far, so good.

Bob, G 4+5 (contained)

[quietcorner]

Wow, those are good numbers post-radiation.

My partner had the same treatment as you, same Gleason score, 4th months post RT and post ADT he is above 1.0 - would love to see his .004!

[Mgtd]

Funny when I read your post I had to reread my first posting. I had just your standard PAS test so that .004 in your post was supposed to 0.04.

I assume it was a typo but if not I did not want you to be under the wrong impression.

The reason I asked the question is they are training that new PA and she told me that my MO, RO and herself met to talk about my results. So I was just wondering why that would happen over a routine issue.

It is a small community here for example my granddaughter has spent 30 or more hours shadowing my RO as she is preparing for med school. She is interested and exploring radiation oncology.

[Omalley]

I had Proton in 2009 but since I had Gleason 9 they used 3D Conformal for 20 of the 45 treatments. The 3D was not state of the art IMRT was but shockingly Loma Linda hospital didn't have it. If I had it to do over again I would refuse the 3D, I have had several problems from radiation the worst was both my urethers plugged and I had to have surgery to cut out the bad parts and relocate them on my bladder. I have had several exploratory cystostomys to get stones and I guess to just look around and see what was wrong, during that time I had bladder bleeding from the stents they put in. I got 30 HBOT treatments and since all the stents were taken out in early 2023 I have not bled. To answer your question my PSA has run around .40 ever since so I guess the radiation cured the prostate cancer for at least 15 years but it messed up a lot of other stuff. I still walk every day and still can work around the house, I'm at least as fit as an almost 80 year old I know so I can't complaing.

[Mgtd in reply to Omalley]

Well the good news is you are here to tell the story. Like you I am pushing 80 and my goal for my 80 th birthday is to jog/run a 5K.

Thanks to cancer I have spent the last five or six months getting into shape - weights, walking, etc. Right now I am working on sprints to develop cardiovascular endurance and walking 7 plus miles at a fast pace to improve my legs.

I hope to be able to jog a couple of miles by the end of summer and go from there. It has been a challenge but I am making progress which is good. I work at it everyday.

Since I live at 7000 MSL it should help me when I drop to around sea level in San Diego to do the 5K. This town is a center for high altitude training.

This getting in shape for the 5K has been the bright side of this cancer diagnosis.