What was radiated during SBRT and other types of radiation

They radiated me with 2mm margins with the mridian radiation machine. I have heard that the shape of the radiation is more of an oval with a flat edge because of the attention to the rectum area and also the slight movement of the prostate even when we hold our breath. Not sure if this is accurate shape wise but it makes sense.

I believe my first 25 (ish) visits were prostate bed and wider including the lymph node area(s). The last batch were just the prostate bed.

For me, they administered 2.5 Grays of proton radiation to the entire prostate at each of my 28 sessions.

Depending on the nature of your diagnosis, they very likely treated your entire prostate with the same amount of radiation each session.

(There is a protocol called the FLAME Protocol where they use mpMRI to precisely identify the dominant tumor(s) within the prostate, deliver a standard dose to the whole prostate, plus an extra boost specifically to the visible tumor(s). My brother recently had his IMRT radiation treatments using this protocol.)

@brianjarvis , thanks for that information. I didn't ask about that until I was pretty much done with my sessions. Keep blasting it day after day then give it a booster shot at the end!😁

I had five SBRT sessions early this year. In each session they treated bone mets in the L2, T3, and T4 vertebrae as well as the prostate. It was very effective in reducing my tumors and greatly reducing the bone pain, with basically no side effects.

Great, I asked for them to do my prostate and my pelvis during the same session, but they wouldn't. Except for a little burning sensation in the taint during the first day of radiation, I haven't had any side effects either. My dad had radiation back in the 90's for PC and he was partially incontinent for both 1 and 2. I think they got the cancer as he died at 92 in 2015 of we're not sure. He had a few things going on.

@bonanzaman Actually, in his case (per the protocol) at each session they did 2.0 Grays to the entire prostate but, 2.5 Grays to the visible tumors.

There are other combinations they can do with radiation these days, even “cooling” the radiation as they approach an area they want to avoid as well as shutting off the radiation entirely if the prostate moves.

Many things they can do beyond simply zapping each day.

@bonanzaman
Surprising so many of us have the same questions.

Will give you my experience on this. I had the MRI with contrast and found suspicious areas. Biopsies done and had two different opinions on diagnosis and treatment plan.

I chose to have 30 rounds of pencil beam proton radiation at UFHPTI. There you meet every week with your R/O to discuss treatments, side affects, questions etc.. One of the questions I asked was: "Do you treat the areas identified by the biopsies or entire prostate?"

Answer I treat the entire prostate. We want to make sure we did not miss something on the MRI, the biopsies, CTs. He went on to explain that in early stages of PC it is at cellular level and very easy to miss something with a biopsy.

You know it means healthy tissue will get radiate but I agreed with R/O best to treat all in case missed something. So my experience with this mirrors yours.

My oncologist said he radiated the whole prostate just to be safe. I had 2 small lesions right next to each other. He did 5 treatments on the Radixact machine, which does microbursts of radiation while rotating 360 degrees around you. Supposedly that lets them radiate the prostate from all angles. PSMA PET was clear, only showed the prostate involvement.

@bellasdad
I was also curious about the same questions. I was treated on the MRIdian platform and at the end of my final treatment I asked the nuclear physicist that was there for each of my five treatments if she could tell me the answers to some of the items you questioned. So she was very interested in telling me all about it, I think she was happy that a patient was interested. So, yes in my case they treat the whole prostate each session. I had five and in each 5 they used 17 different scan angles to achieve their goal. When I did mine I asked from the very beginning if I could watch the imaging live on the TV monitor in the scan room instead of the nice soothing nature images displayed to relax you during the treatments and they said sure no problem, so what they were seeing I got to see each time. What it showed me was my prostate with the 2mm border live and I could witness my prostate move at times, but the movement never went outside of the border. The physicist then showed me on her monitor each of the 17 beams were rectangular and the program broke down the coverage area. She explained how that beams were also adjusted in intensity to be of higher concentration over lesions and lesser of my urethra and other non cancerous areas.. etc. But she made the point to say that all of the prostate is treated but in a very specific and controlled way. I wish I had more to spend with her, it was very interesting and I could have learned more. My total at the end was 42.5 gy. Hope that helps, but were all different.