Final decision on treatment: Viewray or Truebeam?

rockin2047: one of the great benefits of the Mridian is real time MRI mapping and dynamic mapping capabilities. I had an MRI and a CAT scan used for preliminary mapping. They were used as a guideline for the initial set up and the real time Mri in the Mridian was used to finalize the mapping. They did not have to use the dynamic planning capabilities of the Mridian as my body did not move internally or externally in a way that required it but it was there if needed. In other types of cancer, where the organs move more, the dynamic planning capabilities of the MRIDian become more important.

Great summary. Although I chose 5 treatment proton at Mayo Rochester where they use Hitachi kit, the statement, "There are no well designed randomized studies comparing proton with photon" is consistent with all I have read and been told by urologists and radiologists. The one statement made by those perfming the procedure that I question is whether Radical Prostectomy is still the "Gold Standard". Photon and Proton have been shown to have equal long term outcomes.

I think men are finding better information regarding the risks of surgery that occur immediately. They are learning about penile shortening, ED and incontinence. The advances in RT have been non stop. ROs are learning how to reduce side effects. Hopefully we will soon see adaptive radiotherapy and automatic gating which will improve safety and side effects profiles to all delivery systems.

I think you intended to say "Proton has all the energy through only two paths." What I want to know is whether the Photon radiation is controlled by MRIdian so that it does not escape outside of the prostate when the beams are turned ON? From what I've read, Photons (xrays) pass right thru tissue and don't stop until they leave the body. What is your understanding as to what is going on when treatment is being applied ?

With all the protons passing through opposing paths 180 degrees, You get more concentrated energy along the path. The role of the Bragg effect is negated when the two beams contribute on both sides. With automatic gating, smaller margins & adaptive planning the dose received by OAR is likely less than with the proton. We can't know the actual dose with proton as structures move and can move OAR into the beam depositing more energy in the bladder or rectum.

Although we can theorize that one method is better than another, the only randomized data we have shows reduced side effects with MRIdian. Until there is real evidence as opposed to marketing hype, I'd lean to MRI guided 5 treatment SBRT, than 45 CT guided proton with larger PTV margins and no protection during movement.

WOW, a Decipher low risk of 0.26 ? That's better than mine at 0.37. According to Decipher, Low Risk means you and I are perfect candidates for Active Surveillance (AS). I just had a consult with a medical oncologist for a second opinion at a major hospital in Wash, DC. He said I was at such a low risk that I should not even consider any treatment options for now and concentrate on closely monitoring my PSA which is at 3. The schedule for PSA tests would be a minimum every 6 mos and a maximum of every 3 mos. If the PSA were to get up to say 8 or higher, then he would take a closer look at things. Be sure to read this article on the internet using the following Search terms "Study finds prostate cancer treatment can wait for most men". Keep in mind that prostate cancer cells grow VERY slowly in about 80% of men so time is on our side. I hope you read this before you go under THE BEAM !

Your case is interesting. On the one hand you say "to get a PET scan which showed involvement just outside the gland in the seminal vesicle which didn't show up on MRI or CT scan." However, on the site health dot costhelper dot com it says "PET scans do not show images as detailed as those produced by a CT scan or MRI, but can show chemical activity and blood flow as other scans cannot." So was the involvement detected as a result of the chemical activity/ blood flow only? Please say what your PSA was at that time. I've read that there are 2 things that would require a PET scan: a PSA blood level of 20 or higher or a Gleason grade of 7 (3+4) or higher puts you at higher risk of metastatic prostate cancer. So was your PET scan because of a Gleason 7 and/or a PSA of 20 or higher or both?"
My PSA is only 3 but have one Gleason 7 (3+4) along with a Decipher Low Risk of 0.37. Thus I wonder if a PET might be done since my Gleason is a 7. Any thoughts?

PSA was 0.3 when PET was positive. It is CT so yes the resolution is much greater with MRI, but the PET is far more sensitive because the radioactive tracer binds to PSMA on the cancer cells surface.

Do you recall what your Gleason number was? Perhaps 20 or higher which caused a PET to be done for you?

GL 4+3 is intermediate unfavorable which gets the PET ordered or should. Not sure what you mean by Gleason 20??

I was part of a PSMA PET study at UCLA and chose to push for it.