Type of Radiation machines

I researched the facility on line, but otherwise I would have asked. I had a Varian Edge. Which is a top of the line machine.

Here's what I understand so far, as a layperson:

Proton-beam and SBRT (aka "cyberknife") are both very accurate for targeting small areas and have similar outcomes for overall survival, but proton beam can have fewer side-effects in certain cases.

IMRT is a blunter instrument affects a wider area (think "cyberclub" instead of "cyberknife" 🙂 ), which is usually not ideal. However, it can be a better choice if your cancer is just starting to spread locally (stage 2), since it will zapp any stray cancer cells near your prostate as well as the tumour itself. It will likely produce more uncomfortable side-effects, though.

The older "slap on a lead apron with a cut-out and fry you" (I don't know its real name) radiation therapy seems to be mostly gone now, and good riddance. That's where most of the horror stories about radiation therapy came from.

We don't have proton-beam yet here in Canada (it's incredibly expensive to build, and requires a 3-story high room to house the equipment from what I've read). They're talking about building a few facilities, but in the meantime, provincial governments pay to send young/high-risk cases like pediatric brain cancer — where side effects could be more than just a nuisance — to U.S. facilities for treatment.

I have enough saved that I could have paid for proton-beam therapy in the U.S. if I'd known about it at the time, but I still wouldn't have. My side effects from SBRT weren't that bad, and I was still in a wheelchair at the time, so it was nice being treated just a 20-minute drive from my house with the support of my family and my own cancer team. Also, if I'm not still here in 30 years, I want there to be enough savings left that my spouse can spend her old age in a comfortable assisted-living apartment, not a sketchy publicly-funded nursing home. I don't think *maybe* avoiding a few months of bladder infections and incontinence (now well behind me) would have justified taking that away from her.

@caryg1955
You are in right place to asked about different radiation machines. And you are going to get a lot of suggestions. I am going to give mine but remember we are not R/O or urologist so what is good for us may not be what is best for you.

Photon radiation methods us a type of radiation that enters body and exit body.
Proton radiation is a controlled beam and enters body with less radiation and DOES NOT EXIT the body.

That is the major difference in these two. There are other type radiation treatments out there but I am not familiar with them so can't comment.

After getting Decipher test, bone scan, PSMA, I did my own research. I then talked to my primary care physician (Mayo) and chose proton radiation pencil beam. Proton beam can be programmed to stop at the treatment locations and not proceed through the body like photon does. Research and PCP states this reduces the amount of radiation damage to rectum and other tissues and organs that photon would cause as proceeds throughout body.

Photon though as some very specific treatment options and has improved over the years with methods to reduce damage to surrounding organs and tissues.

If you decide on radiation please mentioned Space/Oar if they don't. It is a special gel that is injected to move the rectum away from the prostrate to reduce radiation damage as the rectum rest right up to prostrate. Also I and many others will suggest tests that help determine the specific treatment fo you and help you decide on which treatments are best for you. This would be after your MRI and biopsies are done and reveal cancer. Decipher, PSMA, bone scan.

I had VMAT delivered by a Varian Truebeam LINAC. Now one year post-treatment and my PSA continues to drop. There were minimal side effects during and after as that treatment method is designed to spare healthy tissue. I am very pleased with the outcome.

In May I 2024 had five courses of SBRT delivered by a Varian TrueBeam STX, which apparently was their most recent model. The RO and the radiation techs were gushing over it like someone would over a new car or a baby. 🙂

The overall process was amazingly smooth. When the beam "lost sight" of the fidicual markers in one session for some reason, such as organ movement, etc., it halted the process until it was back on target. Incredibly accurate to within less than 1mm. I have not had a followup with the RO yet, but my PSA during my annual exam last week was .17, down from 14.8 about a year ago.

I had SBRT with the same machine and your comment about the techs made me laugh. Several of them were VERY excited about this machine, but it also broke down three of the days I was due for treatment so I had to go at 8 and 9 PM instead of my normal time. Not sure if the techs are salaried or hourly. If hourly, they were probably so excited because they got to earn a lot of overtime 😃.

The Varian Edge is an amazing machine.

@caryg1955 i had the MRIdian linac machine. Unlike other radiation machines, except the Elekta, it has a built in MRI so you are treated with real time imaging, instead of fused images which is the case with proton and other types of radiation machines. The MRIdian allowed margins around the prostate to be 2 mm instead of 3-5 mm (used by most other radiation machines) so healthy tissue had less exposure. My side effects were minimal with temporary urine restriction. The machine had auto shutoff and real time dynamic mapping. The mirage randomized trial showed that the built in mri was significantly more effective than non built in mri radiation machines.

This is interesting. Does the built in MRI mean that the usual MRI restrictions apply (no metal in the room)? Are you enclosed in a tube like a traditional MRI?

We have MR-Linac at my cancer centre according to a 2020 press release, but I was treated with CT-guided SBRT in 2022, which was still very advanced (they use real-time imaging to guide the treatment). I don't know if the metal rods in my spine affected the treatment decision: I was still in a wheelchair at the time and focusing more on physical rehab, so I didn't know all the questions to ask.