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MRI linac at U Virginia or Philadelphia and my Florida experience

Posted by erbill @erbill, Jun 22, 2025

wondering if anyone has had sbrt with mri linac in Philadelphia or at university of Virginia. mridian or elekta unity? Were you pleased with the RO? spaceoar?
my experience lately is that even though a facilities website indicates they use the mridian viewray on prostate cancer doesn't mean they are.
i have had appointments at both moffit and Orlando health and found out the machines were taken off line recently. they don't want to pay the exhorbitant maintenance contract.

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beachguy | @beachguy | Jun 25, 2025
In reply to @bens1 "@beachguy It sounds as if you are saying the images from a higher Tesla is not..." + (show)
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@beachguy
It sounds as if you are saying the images from a higher Tesla is not as good as a lower Tesla?

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I’m not saying or implying that. I did have the same question and what I posted was information that i found. I’m sure there is more information available if you want to research it.

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erbill | @erbill | Jun 28, 2025
In reply to @beachguy "I wondered the same regarding the magnet strength of the MRIdian and this what found when..." + (show)
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I wondered the same regarding the magnet strength of the MRIdian and this what found when I was going for my 5 treatments….. The ViewRay MRIdian system uses a 0.35 Tesla (T) magnet to achieve high-quality images and specific advantages for radiation therapy.
Here's why ViewRay opted for this field strength:
Optimal field strength for radiation therapy: The 0.35 T magnet allows the system to avoid image artifacts and distortions in the dose distribution that can occur with high field strength magnets.
Geometrically precise images: This low field strength leads to geometrically precise images, without susceptibility distortions or chemical-shift artifacts.
Accurate dose distributions: The precise images enable accurate dose distributions for treatment.
Reduced tissue heating: The lower radiofrequency (RF) excitation frequency at 0.35 T minimizes RF induced tissue heating, allowing for uninterrupted MR imaging during treatment.
Split superconducting magnet design: The split superconducting magnet at 0.35 T allows for an unobstructed beam path, addressing technical complexities of combining an MRI with a linear accelerator.
Reduced magnetic susceptibility artifact: This low field strength reduces artifacts caused by spinal hardware and other materials, improving visualization of targets and organs at risk (OARs).
In essence, the 0.35 T magnet on the MRIdian is chosen to optimize image quality and treatment delivery in the context of MR-guided radiation therapy.

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I have been reading about the mri linac systems. The viewray does offer
imaging with fewer artifacts.
Also, My research indicates that the ViewRay system features automatic beam gating—if the prostate moves outside the target boundary, the beam pauses and automatically restarts when the target returns, making the process seamless for the patient. In contrast, the Elekta Unity also stops the beam if the target moves, but may require manual intervention to resume, which can be less seamless.
I have found no evidence that clinical outcomes differ between these two systems.
I have chosen SBRT MRI-Linac treatment after considering the options offered to me.
While both Dr. Nagar and Dr. Zelefsky use the Elekta Unity, there is no evidence to suggest their outcomes would be worse than those at UCLA using the mridian. Btw I have an appointment with Dr Nagar in July.
Some of these differences rile up my doubting behaviors . They probably don't matter in capable hands. My wife would likely be frustrated etc if I kept revisiting doubts.
Thanks for reading. Writing this helps to alleviate the anxiety.

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tenneyd | @tenneyd | Nov 25, 2025
In reply to @beachguy "I had my MRIdian treatments in Philly at TJUH. My experience was great no complaints. My..." + (show)
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I had my MRIdian treatments in Philly at TJUH. My experience was great no complaints. My RO used the Barrigel and not the SpaceOAR. Both my RO and the Nuclear Physicist were happy to answer all my questions about planning and show me on the control system how my radiation was directed and placed for all my individual beams. The technicians for the MRIdian that cared for me during my treatments were awesome.

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@beachguy Good news! I believe you said in earlier posts that your doctor was Greenberg, and Picker has also been noted there. But how did you get an appointment as only other doctors are offerred?

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