Rad Chat Live #22 at the MR Linac Consortium 2026 in Montreal: Dr. Mischa de Ridder - Glottis MR-Linac Treatment

What made you pick this tumour type first?

Because I like head and neck.

So specifically for glottis?

Yeah, so for For the MR-guided treatments, the benefit of MR-guided is that you can see moving targets and the glottis moves during swallowing, speaking.

Of course, we tell patients not to speak, but it moves with breathing, motion.

So the benefit of the MR is that you can see the movement and also we know that the cartilages of the larynx are very vulnerable.

So if you radiate them too much they'll die and then patients get in worst case scenario even lose their larynx because of the toxicity.

With the MR we can see actually where those cartilages move towards so we could track the cartilages and on the same side deliver the high dose to the tumor.

That visibility seems to be something that is influencing practice because of the fact that maybe in standard conventional radiotherapy we'd never have the capability to see just how much things moved and from your perspective what's been the most surprising finding so far from your research

um actually that how much movement there is internally in the larynx so we see that patients lie on the table for like 25 minutes.

Besides of the regular breathing motion we also see that sometimes patients relax their tongue and when relaxing their tongue we see internal movement of the larynx.

Things you cannot see on the outside but you can see on the inside.

If you cannot see it and just irradiate blind, you irradiate cartilages.

so that is a very nice thing that we see and we already knew that and yeah what i think is really cool is that yeah we have treated 10 patients so far and those 10 patients all are doing very well yeah with only limited toxicity of course yeah the trial is still running so we do not have very long-term toxicity but in the acute setting yeah patients just go to work

What made you pick this tumour type first?

Because I like head and neck.

So specifically for glottis?

Yeah, so for For the MR-guided treatments, the benefit of MR-guided is that you can see moving targets and the glottis moves during swallowing, speaking.

Of course, we tell patients not to speak, but it moves with breathing, motion.

So the benefit of the MR is that you can see the movement and also we know that the cartilages of the larynx are very vulnerable.

So if you radiate them too much they'll die and then patients get in worst case scenario even lose their larynx because of the toxicity.

With the MR we can see actually where those cartilages move towards so we could track the cartilages and on the same side deliver the high dose to the tumor.

That visibility seems to be something that is influencing practice because of the fact that maybe in standard conventional radiotherapy we'd never have the capability to see just how much things moved and from your perspective what's been the most surprising finding so far from your research

um actually that how much movement there is internally in the larynx so we see that patients lie on the table for like 25 minutes.

Besides of the regular breathing motion we also see that sometimes patients relax their tongue and when relaxing their tongue we see internal movement of the larynx.

Things you cannot see on the outside but you can see on the inside.

If you cannot see it and just irradiate blind, you irradiate cartilages.

so that is a very nice thing that we see and we already knew that and yeah what i think is really cool is that yeah we have treated 10 patients so far and those 10 patients all are doing very well yeah with only limited toxicity of course yeah the trial is still running so we do not have very long-term toxicity but in the acute setting yeah patients just go to work