Radiation: 20 Days Straight Or Once A Week For 5 Weeks?

This is a strange choice. Everybody I know that has had SBRT radiation has it done in about a week and a half. They get at least three days in a row maybe a weekend and two more days. I had it on my spine and it was three days in a row.

Why are they having you only do it one day a week? Are they overbooked? You might ask them why You’re getting only one dose a week when people usually get multiple doses of SBRT a week.

As for whether getting 20 sessions or five sessions, The results are pretty similar. Side effects are pretty similar. When I had my IMRT radiation, they did it in 40 sessions giving A lower dose of radiation every time. That resulting me having no side effects at all. People who get 20 sessions do have some side effects frequently. SBRT can also cause side effects since it’s a higher dose of radiation each day. The most common side effects are urinary issues.. The radiologist that do SBRT say it is more effective because the higher dose kills the cancer cells quicker. There was a Radiation oncologist at the latest PCRI conference that discussed this. You could actually watch the video, skip through till you find the radiation section.

The five sessions are a lot more convenient. Too bad they can’t do it in less time.

I had 5 treatments with the Mridian machine with a built in MRI. What the doctor could see, in real time not fused images, they could treat. The exposed healthy tissue was 2mm vs 3-5 mm for other types of machines. I had slight urination issues after the third treatment but that was handled overnight with Flomax. In terms of side effects, you might want to consider this in your "calculation" of SBRT radiation machine choices and the amount of healthy tissue exposure from a built in MRI machine vs fused images. The Mirage trial demonstrated that MRI-guided SBRT significantly reduced acute grade ≥2 genitourinary (GU) and gastrointestinal (GI) toxicity compared to CT-guided SBRT. The trial showed a 60% reduction in odds of grade ≥2 GU toxicity with MRI guidance and hence, far fewer side effects.

I’ve never heard of a single weekly dose for SBRT. I’ve heard of SBRT given a dose every day or even every other day.
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I chose the 28 sessions of proton radiation rather than the 5 session SBRT. Though the biologic effective dose is probably similar, I wanted to avoid the higher per-session radiation dose.

At the mid-year PCRI conference in 2023, Dr. Rossi talks about this during a Q&A session at https://www.youtube.com/live/WTqPnSRYtW4
—> Starting around timestamp 4:30:45.

That is really odd since most SBRT to the prostate is done in 5 sessions in about 2 weeks.
Did your RO mention anything about you having issues with your bladder if you did a regular regimen? I’ve seen protocols of having SBRT once per week for 5 weeks to alleviate SE’s. 20 treatments sounds more like IMRT, which is always a lower dose than SBRT…
Phil

@jeffmarc
Anyone with experience in EBRT 5days/week over4-6 weeks….can you tell me how you feel after the daily treatments? Tired, exhausted, or ready to go out to dinner or to pool league that night?

Hmmm

Odd, I had SBRT in April 2023.

It was five treatments, 8 Gya each one, every other day.

M-W-F
M-W

As to the side effects of SBRT vs standard IMRT, the literature I've seen says not an issue.

Kevin

Kevin

I had SBRT every other day for 5 days on my prostate and then three sessions every day for my pelvis. I had a little burning in my taint the first day and then it subsided. I couldn't imagine doing 40 days, but I would if I had to. It was more phycological for me than anything else while it was happening. Each event on my prostate was about 4-5 songs long, and for the hip was more like three songs long.
I really didn't have any other effects than the slight burning sensation that went away. Like others have said, ask your doctors why you can't have all your treatments as fast as possible.
From what I've heard or read, the SBRT is the best way to go.
MAybe get a second opinion.

It would be a much higher, but not x5 for SBRT since the higher dose has a more than linear stronger effect.

SBRT would be harder on your body, but as others have pointed out, from what I've read the studies claim the long term side effects are the same and the short term differences are very minor. It may be more of a concern if you have existing conditions that make the short term side effects more worrisome. Though I'd hope your doctor would point those out.

My RO submitted this Prostox test ( https://mirakind.org/prostox-testing/) that uses genetics to help inform if you might be a better candidate for one or the other. It cost me about $400 since my insurance doesn't cover it. I'm not so sure I buy the science of it, but it suggested I'd have a lot of trouble with traditional fractions and do very well with SBRT. If you've still got time, you might reach out to your doctor about it.

I'm not sure about the differences in MRI-guided vs CT SBRT are that great. I was given 5 sessions on a new, adaptive CT-guided machine (Varian Ethos). It scanned the pelvis prior to each session and adjusted the plan if the prostate and other organs had moved slightly. My SEs improved quickly and were similar to what I've read from those who had MRI-guided SBRT. If SBRT is available on any new machine, I would select that over the standard IMRT dosing .

@tk192 The entire process will make you a bit more tired (even more with ADT) but nothing an afternoon nap won’t help.
I think it’s important to continue whatever daily activities you normally - including exercise, dining out or going to work…
Phil