Need help deciding which radiation treatment system i should go with.

On the website of Varian, who makes TrueBeam, of the five mantioned side effects you will find

Changes in bowel and/or bladder habits
Rectal/urethral bleeding

Ask the doctor if there is no benefit, considering the company that makes the products says the above. See if they will agree,to a spacer like SpaceOAR, Barrigel, or BioProtect

Hi @ngershon I can only speak about my own experience, andvan't comment on Cyberknife or TrueBeam.
In February, I was Gleason 7 (3+4) on three of 14 cores, (0+2) on four cores, no metastasis. I had gold seeds fiducial markers implanted on March, at which time I asked about SpaceOAR but was told by my care team that it's not necessary.
My cancer center has an Elekta MR-Linac for MRI-guided radiation, but they only use it for patients requiring greater accuracy. Most patients are treated (including me in April 2025) with older versions of Elekta machines that use MRI-guided radio planning, and mini-CT scans before each treatment. My RO assured me that even with a wider margin than the latest Elekta MR-Linac, the older Elektas are all good and very accurate with the help of the fiducial markers and the mini-CT scans before each treatment.
For a few days after my SBRT was completed, I noticed some mucus and small traces of blood on my stool; I reported this to my RO. A poster in our support group indicated that the mucus meant the rectal area that may have been radiated was healing, but the veins were still sensitive, so the stool picked up some blood on the way out.
In the last 2-1/2 months or so, I have no issues or side effects to report. Couple days ago, I read that another in this our PCa "brotherhood" also had no SpaceOAR and had proctitis after about right months; he indicated that a little blood soon after treatment wasn't concerning, but if experience more bleeding after 8 months or, it may be a concern.
I will see what happens in the next six months. I am not overly worried; hopeful that I won't develop chronic proctitis.
Each of us will have our own unique experience. I hope mine will help you decide whether to ask for fiducial markers and undergo MRI-guided treatment (smaller margin) or settle with with the like of .MRI-guided planning only/not MRI-guided treatment. I would have liked the latest Linac machine if it was available to me.

I had 28 sessions of EBRT for a couple of Gleason 3+4=7 lesions, localized, employing a TrueBeam system. I had fiducial markers implanted and a SpaceOAR hydrogel pack injected.

I was told that the TrueBeam unit does do real time monitoring and adjustment for target position changes. That was the purpose of the fiducial markers - to allow the system to "see" exactly where my prostate was positioned throughout the treatment.

Could be there are different types of TrueBeam systems out there, and I'm afraid I can't tell you anything about the specific unit that delivered my treatments.

In my case, I formed the impression that at anytime during the MRI-guided treatment, if the prostate moved (like because I coughed) out of position, the machine would automatically stop, allowing the technician to make the necessary adjustment, then resume the radiation treatment. With the older machines, the mini-CT scan before each compares the new images with the "planning images" and makes the adjustment -- before but not during this round of treatment. Essentially, that's what I missed with the older machines (there were so many of those at the cancer center where I was treated). Note that the older machines were "top of the line" before the latest MRI-guided machines became available. Of course, if ever possible we would prefer the latest so we gave the least risks on healthy tissues damage, but it's a limited resource in some, maybe many, cancer centers.

I didn’t really answer the question.

Cyberknife has some real advantages

Cyberknife can be done in 5 or fewer sessions.
It incorporates a respiratory tracking system that monitors tumor movement during treatment, adjusting the radiation beam accordingly to ensure accurate targeting, even with patient breathing.

CyberKnife is known for its sub-millimeter accuracy in targeting tumors.
CyberKnife treatments are typically delivered in a shorter number of sessions, sometimes as few as one to five, compared to conventional radiation therapy.

My brother had his prostate treated with CyberKnife about three years ago, 5 sessions, and he’s doing great. I know a lot of other people with the same result. They can also zap other metastasis if they happen to be there at the same time.

TrueBeam Is EBRT. It takes a lot more sessions
It incorporates advanced imaging technology to visualize the tumor and surrounding anatomy, ensuring accurate targeting and dose delivery.
TrueBeam can deliver radiation at high speeds, potentially reducing treatment time and minimizing patient movement during treatment.
TrueBeam also includes motion management features, such as respiratory gating, to compensate for tumor movement during treatment.

The number of TrueBeam treatment sessions for prostate cancer varies, but a common approach is 5 sessions over approximately 10 days, or 28 sessions over 5-6 weeks. Some patients may undergo treatment in 5-7 sessions over 1-2 weeks. The specific number depends on the treatment approach (e.g., stereotactic body radiation therapy (SBRT) or conventional fractionation) and individual patient factors.

The "better" system depends on the specific situation, including the tumor's location, size, and proximity to critical structures. According to clinical data, CyberKnife can be particularly effective for tumors in complex locations or when protecting surrounding healthy tissue is crucial, while TrueBeam may be preferred for tumors with simpler shapes or when high dose rates are a priority. A consultation with a radiation oncologist is essential to determine the most appropriate treatment approach for each individual.

Lots of options. Can you get the TrueBeam Treatment done in just a few sessions? Which one is better for you?

Well, at least you have a lot of things to discuss with the radiation oncologist.

@ngershon
I had the MRIdian linac machine, 2 mm margins instead of 3-5 mm for other radiation machines and I had 5 treatments. I believe the MRIdian or the Elekta, are superior radiation machines because they have built in MRI as part of the machine and don’t use fused images so what they see live is what they treat, plus the lower margins mean less exposure and side effects.

I had spaceoar as it gives a bit more separation between the rectum and the prostate. All five of the radiation oncologists I spoke with were for it. Again, less exposure affects side effects.

Yes, the MRIdian Linac and the Elekta MR-Linac (Unity) are comparable.
I was treated with the Elekta Versa HD and it's also a linear accelerator, so the techs told me. So I asked my RO, "You told me that the MR-Linac is only for patients who need better accuracy and who could not have the gold seeds implanted, but the techs told me they're using Elekta linear accelerators?"
My RO said, "All our Elektas are linac machines (4 mm margin). But only the MR-Linac does MRI-guided treatments (2 mm margin)."
Then, I figured the difference between MRI-guided treatment and "MRI-guided radio planning, mini-CT scan- guided radiotherapy."
I have no complaints, knowing that there were other patients who needed the MR-Linac more than I did, it's a limited resource (only two of them within a 500-kms radius where I live), and I wasn't paying with my own or my insurer's money -- my treatment was taxpayer-dollar funded.
I am happy for you in the U.S. Many of you have access to MRIdian, Elekta MR-Linac, Cyberknife. And TrueBeam, or others not listed here.

I had my 5 SBRT treatments performed on the MRIdian platform. This was performed over a two week period. I also had the Barrigel implant done two weeks prior. So far now after 4 weeks Post treatment and I keep my fingers crossed, I have not experienced any GI or GU changes. I’m back to as I was prior to treatments. I personally believe that the spacer provides extra protection to the rectum and I would ask for if not suggested by your RO. When I had my pre-planning session I also had a catheter placed so that the urethra would be visualized better to protect the urethra during treatments. The catheter was only used for the pre planning procedure.

I had 28 sessions of Proton with Spaceoar. While many individuals recommend the treatment they had I would do differently now. MRI guided SBRT with Spaceoar or other gel in my mind is absolutely the best. I find too often people who have had longer sessions of CT guided treatment having difficulties, maybe not disasters but changes in bowel or GU function that I think could be avoided. I am not a doc but thats my 2 cents.

Thank you all for help. Have to do more research now. Again thank you.