SBRT Late Stage Radiation Toxicity-Anyone Experienced These?

Thanks Phil. I’ll look forward to the answer. It would be a shame to lose the gated technology!

This is the first MRI-Linac Elektra machine in Canada (one of the "first few in the world").

Strange situation there with MRIdian systems still working. Bankruptcy was filed in July 2023 on October 25, 2023 they said that they would cease operations and that the MRI machines would become non-functional that day.

I can’t find any reason they are still working. Searching hasn’t shown new owners and ViewRay seems to be functioning.

I believe interstitial radiotherapy (f/k/a [permanent] 'seeds') should be considered. Brachytherapy is another term. There is low dose permanent seeds or the temporary HDR high dose. I recommend seeing You-Tube videos produced by the Prostate Cancer Research Institute (pcri.org) When I asked my surgeon he said "Good luck finding one!" Few of the oncological surgeons even get training in the procedure. SBRT >27K$, IMRT >35 K$. 'Seeds' one and done 5K$?

Oddly the radiation oncologist on the team commented that 'boost brachytherapy' might be done after 'IMRT'
(I guess a member of the team found one somewhere else in the USA as it is unlikely the team surgeon would not have known about an in house option to my question!)

The Mridian is still being used by a number of hospitals and a new institution has bought them. The new institution hired original employees from Viewray in order to make sure that they were supported correctly. Those that are still using the Viewray are paying $1 million a year for their support. So far so good. It was not Elekta who bought them. Elekta Unity Is another machine that has built-in Mri and similar functionality to the Mridian. They are owned by a large institution.

This is the Elektra MR-Linac. The list of cancer centers who helped develop the Elekta is incomple (missing one in the screen shot).

@vircet
The Elekta came out after the Mridian and it was good to have an alternative MRI Linac. The Elekta started out with fewer capabilities than the Mridian, such as auto shutoff when the patient moves. They may have added that and other benefits since I looked at it and MIM Software has partnered with GE since then and they provide the software for the Elekta so there is a lot going on with that machine which is positive but they both have real time/built in MRI, which is most important, as it reduces the margins so less healthy tissue is exposed.

....G3/4 you should consider 'interstitial radiotherapy' (a/k/a permanent seeds).

First, thank you to @heavyphil, @jeffmarc, @vircet, and @bens1 for contributing information about the somewhat confusing availability (or lack thereof) of gated SBRT treatment centers. This is an example of the tangible benefits of this portal and the incredible knowledge of the men who participate in it. @bens1's comment about some treatment centers hiring former Viewray employees to maintain their existing systems and preserve their investment makes sense and would explain why some centers no longer use MRIdian, while others continue to do so.

Here is some additional information I found this morning:

"ViewRay Systems, Inc. (formerly known as ViewRay, Inc.) was a company that designed, manufactured, and marketed the MRIdian MRI-guided radiation therapy system. The company ceased operations and filed for Chapter 11 bankruptcy in October 2023, and its assets were acquired by Chindex Medical Limited (a subsidiary of Shanghai Fosun Pharmaceutical (Group) Co., Ltd.). " At least one site that had ceased MRIdian operation in 2023, the Siteman Cancer Institute at Washington University Medical Center in St. Louis, resumed delivering MRIdian treatment in February of this year.

@thmssllvn, thank you for your suggestion! You are right! Brachytherapy is an attractive alternative and was my first considered alternative to gated SBRT because the seeds are placed in the prostate and travel with it as it moves. Exposure of OAR to radiation toxicity due to prostate movement isn't an issue. I discussed brachytherapy as an option with two radiation oncologists at Mayo Rochester and got mixed recommendations because of my history of moderate LUTS (lower urinary tract symptoms). One didn't think brachytherapy would be a problem with my level of LUTS (14-15 on AUA / IPSS Urinary Symptom Score). One expressed concern. A 2023 study (https://doi.org/10.3390/curroncol30060426) demonstrated an average increase in IPSS scores of 7-13 points for months 3-9 after brachytherapy, gradually reducing to +3-7 points above baseline at 18-24 months. During that period, a patient with pre-treatment moderate to high-moderate lower urinary tract symptoms (LUTS) would have an International Prostate Symptom Score (IPSS) score in the low to upper 20s (Severe) and be at moderate risk for prolonged catheterization. My understanding is that patients with pre-treatment severe LUTS (IPSS scores > 20) are not candidates for brachytherapy without first addressing LUTS. Additionally, my understanding is that the surgical address for LUTS (TURP, HOLEP, TULSA) often precludes brachytherapy in prostates less than 60-70 g because there is not enough remaining prostate tissue to place brachy seeds safely. I may revisit brachytherapy, pending my investigation into gated EBRT.

For others reading this, I am not a doctor. I am educating myself as a patient about treatment options so that I can make the best choice, given my diagnostic classification (Gleason 3/4, grade 2, with no apparent extracapsular involvement) and quality of life (QOL) considerations.