SpaceOAR causing issues

Well, I had my two-year PSA test about 4 weeks ago, and I'm happy to report that it is behaving itself, as I am still in the undetectable range (< 0.02). After about a year, all of the minor side effects have gone away. I was remarking to my wife some time ago that I actually have trouble remembering all of the tumult and anxiety I went through at the time. The human memory works in mysterious ways!

My journey still goes on, and I'm having a chance to pay it forward first hand at the Cancer Center where I was treated in 2023. A tumor in my head that was operated on in 2021 is beginning to grow a little, so my Neurosurgeon, who follows my annual MRIs, suggested that I do a 30-session radiation treatment on the spot to shrink it down, hopefully on a permanent basis (hey, I'm 70. 10-15 years is "permanent" in my book!).

Anyhow, I'm now back to the same location for this round of radiation as I was 2 years ago, with 24 of the 30 sessions now behind me. I've gotten to meet and talk with some other patients waiting for their treatment, mostly for Prostate Cancer. I'm always happy to put myself forward as someone who went through what they are now facing, stressing the positive recovery that I've had. Even more so, I have shown little or no side effects of this round of treatment, even though the location of the beam is in a much more precarious location this time. Maybe it's genetics, or a very positive attitude towards the Prostate and now Brain "problems" as eminently "fixable" with little upheaval to my life.

I guess you are now past the SBRT sessions and are getting back to a normal life. It's not exactly like it was before all this started, but close enough to what a guy moving through his late 60s would have expected.

Vircet, I did not have SBRT but everyone I know or met in the hospital who did have a 5 session protocol, had a gel spacer.
Fiducials only help the machine track the prostate - they do not block any radiation from getting to the rectum.
Beams pass right thru the prostate and hit everything before passing thru the body - the rectum and bladder being the most susceptible to damage.
I had 25 salvage treatments and could not have a spacer and even though the radiation per session is less than that of SBRT, the damage is still cumulative. So I could still have proctitis down the road, even though you are experiencing it now. No one is unscathed! Best of luck to you,
Phil

I haven't had any negative surprises as of this date. (fingers crossed) Keep in mind, my radiation was salvage in nature, likely less than primary treatment type radiation.

Thanks, Phil. I had 8 Gy per treatment x 5 = 40 Gy cumulative. If this is too private for you, can you reply by private message how many Gy cumulative you had over 2 treatments?
I appreciate your putting into perspective, the fact that radiation passes through the body. All along I thought it stops at the target -- the beams came from many directions and meet at the target point. so I thought the "focus beams" stop where they met, now I got to think they disperse again beyond the target and out to the other side of the body. May b e I will do some more reading about how Elekta Versa HD works. Before my treatments began, I discussed MR-Linac with my oncologist, but it was after my second treatment that MR-Linac wasn't the one used for me. The cancer center has many other Elektas but only one MR-Linac which alone cannot treat all patients. I was told that some patients could not have fiducial markers implanted, in those cases they get treated with with MR-Linac. (I got the impression that if the prostate moves out of target position, the machine stops and adjusts before resuming radiation. If so, I wonder if after hitting the target, do the beams scatter on the way out of the body? I would not be asking my oncologist anymore about this -- too late now, maybe I should have asked before my treatment began?)

Hey Vircet, the Linac doesn’t need fiducials because it tracks the prostate in 3D with realtime MRI. Cyberknife uses tomography to track the fiducials which are placed at 3 points on the gland - but it follows the fiducials regardless of gas bubbles or peristalsis moving delicate structures into the path of the beam.
The Linac shuts off if the gland/margin moves out of the target area but the CAT doesn’t - very clear advantage to avoiding tissue damage.
Also, MRI is not - as far as I know - compatible with metal so if you had fiducials placed I cannot imagine that they used an MRI based machine.
Only proton radiation has beams which STOP at the target - all photonic technologies use electrons that pass thru the target. When I first consulted with an RO who used MRIdian he said I would need a spacer.
As far as my radiation I would have to check but I saw a post treatment report which said 6000 to prostate bed and 4500 to pelvic nodes. Don’t think it was expressed in Gy, however.
Phil

Hi Phil,
I believe the values in your post-treatment report are in "centigray (1/100th of a gray)."
If I am correct, this means you had 45 Gy to the pelvic nodes and 60 Gy to the prostate bed.
I read in another literature that 60 Gy is maximum (I am not sure if this information is current).
It appears that Elekta MR-Linac is similar to the MRidian machine.
After my 5th treatment, I told my oncologist that, "You told me the MR-Linac is used only for patients without the fiducial markers. But the radiation team told me they used Elekta linear accelator to treat me."
The oncologist replied, "Our Elektas are linear accelerators. MRI-guided for radio planning. The MR-Linac is real-time MRI, for patients without fiducials. don't worry, all our Elektas are good."
Perhaps, it can't get better than that. Before my cancer center got the MR-Linac, all their prostate RT patients were treated with the older machines, MRI-Guided for radio planning but not real-time MRI during treatment. Based on machine loading and machine capacity, I understand that the lone MRI-guided-real-time machine cannot replace all the other machines in the cancer center -- if I heard correctly, a thousand patients a year. (If I was paying with my own money or my private insurer's money, perhaps I could have insisted on the Elekta MR-Linac. As it is, our taxpayer-funded medical care cannot accommodate all who prefer MRI-Guided treatment, with "MRI-guided for planning" as the second best choice for many.
Thanks for your comments. I am learning. and I hope our discussion can help others still researching on what linear accelerator machine they will be treated.

Hi Vircet, I don’t think you should worry too much about the different machines; you basically had Cyberknife, which is extremely successful with low long term SE’s.
It seems that I myself got more radiation (acc. To your estimates) and I had no Spacer either - we’re either both fine or both screwed😩
But if you rigorously followed the bowel and bladder prep I think we should be OK. All in all I think a gel spacer is a good extra layer of protection for the rectum, but my RO told me that his machine was able to shape the beam around the rectum, since everyday I had a cone-beam Xray as part of the protocol prior to active radiation. It ensured that all the structures matched up with the simulation. Yours used MRI mapping so you had the same thing.
Take it easy and enjoy that cruise you were planning - you deserve it! Best,
Phil

Thanks as usual, Phil. Your feedbacks are most helpful. Yes, our treatments are similar. Even the fact that you had an X-ray before each radiation , and I had a mini-CT scan before each treatment, our respective radiation teams had the same goal of protecting the organs at risk. Best regards,🌄

My radiologist told me regarding spaceor that there is a small percent of people that have problems with the procedure, and there is a small percentage of people that have rectum issues without it, so he doesn't use it since he feels the odds are similar, and the procedure in his office is done under anesthesia. I'm finishing up photon radiation without it and while I have experienced some diarrhea, I'm told this is normal.