About to lock down 28 session IMRT; Side effects ??

I assume this is 28x2.5Gys (typical) for a total of 70 Gys (find out if you do not know). IMRT always hits the complete prostate and it is not ablative at this dose (SBRT at 8Gys per fraction is considered ablative). Cells can take up to 2 years to die. What you need to do is to get with the RO and find out the specifics of the treatment plan. What dose will hit the rectum, bladder, and penile bulb. This is the spill to Organs at Risk (what the OAR refers to in SpaceOAR) and all are calculated with the aim of minimizing side effects. Lower is better but tolerance for radiation differs depending on tissue. Find out what fields are being treated (prostate only; SVs, pelvic lymph nodes etc.) and at what dose since these will be lower than prostate. You can get good results with full bladder and empty bowels with this treatment.

Is there any ADT? If yes, follow penile rehab used by RP patients. Most late RT ED is fibrosis of erectile tissue. This is caused as much by lack of use in patients getting both RT and ADT as it is by direct radiation on penile bulb.

70 gys.
They use Bergel and not the SpaceOAR.
Full bladder and empty bowels is required.
Not treating the lymph nodes
No ADT.

FWIW...Went through IMRT last October with a couple differences. Did have gold fiducials. 20 sessions on a Varian Halcyon, total 55Gy. Full bladder, empty bowel required. No spacer. Already metastatic so target area was wider than just the gland. Side effects were minimal. Mild fatigue during treatment (nap after treatment was welcome), some bowel urgency which could have been just as easily caused by diet change to ensure the empty bowel, minor skin tightening at the treatment site. Side effects pretty much resolved quickly after treatment. I do still deal with some intermittent bowel urgency at times, but it is not severe and its more along the lines of "when I have to go, I have to go now", and certainly not close to incontinence. I had urinary retention going in, still do, so really can't comment on that. Was already on ADT so can't comment on ED either. That said, its important to note that everybody reacts to treatment differently. Best wishes.

Just follow the full bladder/empty rectum protocol and you will avoid all those SE’s.
Practice your ‘no gas’ diet NOW before you begin treatment.
If your team has not given you VERY specific instructions concerning your diet, I would demand an explanation as to why not. Cannot stress this enough…
Phil

I had similar treatments at the University of Cincinnati’s proton center in Liberty Township - 28 fractions of proton radiation @ 2.5 grays per fraction. I used the SpaceOAR Vue gel; didn’t use fiducial markers.

It’s not actually ablating the prostate tissue; it’s damaging the DNA in the prostate cells; later when the cancer cells try to divide and multiply, they can’t…..and die. (See attached graphic.)

I only had 1 day of adverse urinary side-effects during treatments. On the 3rd day of treatment, I had difficulty urinating. My RO told me that with some men there’s an inflammatory response to the radiation, and if that inflammation is near the urethra can cause the issues that I was experiencing. He recommended that I take 2 Tamsulosin/day for the remainder of the treatments. Everything cleared up by the next day; I haven’t had any issues since. I had no other adverse urinary side-effects from the radiation treatments.

Using SpaceOAR reduces the risk of radiation-induced hemorrhoidal irritation, mucosal injury, proctitis, and even secondary cancers. SpaceOAR has also been demonstrated to provide improved GU, GI, and sexual benefits.

How is practicing your full bladder/empty bowel routine going? Consistency with that will help your outcome.

Will they be avoiding radiating your penile bulb? Data show that late ED may be avoided by minimizing radiation hitting the penile bulb —> https://www.icr.ac.uk/about-us/icr-news/detail/avoiding-penile-bulb-with-radiotherapy-could-save-men-with-prostate-cancer-from-harmful-side-effects

I was on active surveillance for 9 years and spent the last 3 of those years researching treatment options and facilities. By the time I chose to have treatments, I had no doubt that I had made the best choice for me.

If you’ve taken all necessary precautions, pull the trigger.

(I live in the Dayton area; if you’d like to get together mid-way between our locations to discuss what’s on your mind, we can arrange that.)

@brianjarvis thanks for much for all your advise. The dr said they are not treating the penile bulb and plan to avoid it but it does get some dose.

Hoping my low Prostox scores translate into minimal GU side effects and Berigel spares my rectum.

Prostox deals with the risk of DELAYED urinary tract symptoms of months to years. The ACUTE symptoms appear to be the same for the various forms of External Beam Radiation Therapy (EBRT) The acute symptoms disappear over time with symptomatic meds,

Has anyone discussed low dose rate (LDR) brachytherapy? It provides the optimal dose. Look up Brachytherapy-101 on YOU-TUBE

Also you could look up HDR brachytherapy and then just 5 sessions of SBRT. Many of the top cancer centers are doing HDR and short course of SBRT with great success. 80-90% NON-recurrence 10 yrs out. Even very good success with just HDR mono therapy if a candidate for it.
Many of the top centers are getting away from LDR brachy (seed implants) and only doing HDR.

Brachytherapy hits only the prostate and spares all other organs.

Did you discuss brachytherapy? I had 44 IMRT treatments for prostate and adjacent lymph nodes during Feb-Apr 2025. I had the fiducial markers and SpaceOAR was injected. I developed diarrhea during treatment that continued afterward and was finally diagnosed with radiation proctitis in January, 2026. I've had a month of Sucralfate enemas and am in my second month of Mesalamine suppositories. Bowel frequency and urgency are the issues. I'm applying to begin hyperbaric oxygen therapy as complementary treatment. My case is not average; I'm someone who seems to get all the side effects. But ask all the questions now.