Transcript
After these fantastic talks, I will try to be as sharp to the point as possible. "Standardizing Radiosurgical Treatment with New Automatic Software for Cranial SRS." You already heard this morning by Dr. Rogers, and [inaudible 00:00:20] something about the elements. And, I'm talking now about cranial SRS elements, which is similar to multiple metastases SRS. It's a little bit different approach. And we have, for several weeks now, the version 1.5 available, which changed also almost completely treatment planning. That means, contouring on elements, and also the treatment planning, and gives you more degrees of freedom than you had before. For that, I'd like to show you some examples. Yeah. And, we did, for instance, this vestibular schwannoma. All right, so the vestibular schwannoma we did treatment planning, that was the actual treatment plan, with Elements Cranial SRS 1. And, in order to get a fine tuning of the isodose as close as possible to the margin of the tumor, we had to introduce so-called tuning structures to achieve the desired heterogeneity. With the new Elements SRS, if you look at the kind of situation here, the slide has changed. The Isodose Line prescription automation achieves the desired heterogeneity. If we look at the initial situation, I'll have to get familiar. Laptop works like this, but I've never used this. Yeah. Okay. When we look at the weighting, normal tissue sparing, and the modulation. And then, you have protocols, we had to go back to write these, rewrite these protocols to set the constraints. That's no longer necessary. You can do that on the fly in the program. You can just slide, you can edit everything. You can even edit the arc if you want. You can edit the dose, and you can do complete dose prescription again like we used to do.
Another thing for me, is quite a situation. I'm out of the generation of brain scan, then I plan, and now elements. But, this is done simply, the triple plan on this [inaudible 00:02:44] vestibular schwannoma. This is another example. These are four tumors that we had, and one is the vestibular schwannoma, the other one is a cavernoma, brain stem. The other one is the small meningioma right down here, and this is another meningioma. You now can put in, like, simply for your dose normalization, your desired volume, tolerated volume, the dose, isodose line, 5%, volume 5%, and the dose. And we look then at the so-called conformity index, the [inaudible 00:03:28] index, which is in elements, and compare those with the elements cranial SRS 1 and 1.5. In all cases of these tumors, we did see an improvement of the conformity index.
Now, we look for the gradient index, which gives you an expression how much dose has spilled outside, and how much the dose, the gradient index, that means the dose [inaudible 00:03:54]. And, we did also see in all these cases an improvement of the gradient index. And, what we have in this kind of situation, we now can make full use of the so-called 4Pi Arc Optimization, and that provides automatic Cochlea Sparing. And, we don't need no longer to put in the so-called special structures to help on Cochlea Sparing. And, when we look at the Cochlea Sparing, there is full trajectory optimization, automation, the 4Pi, and you see that the cochlea dose can be brought down quite considerably, the mean dose, and the maximum dose. And, we are there now in the desired area that we want to have even on the, sort of, relatively complex cases close to the cochlea with the new element versions.
The brainstem sparing with the 4Pi optimization also helps us quite considerably on the conformity index in this kind of situation. When we look at the mean dose and the maximum dose, we also have been able to bring that down. But, here in this kind of situation, if you just go back, we aim, for instance, for maximum Cochlea Sparing in this kind of situation, and then the brainstem sparing is obviously not quite as good. But, if we deliver only 12 gray, this is not a problem. And, the Cochlea Sparing with the full trajectory optimization with the 4Pi, we have the cochlea mean dose, and the cochlea maximum dose for the brainstem as showed. So, we also did find that with this new way, this sort of treatment planning, we had a monitor unit reduction with the full trajectory optimization. And, we were able to avoid OARs, objects of risk in this, and for more complex structures. When we look at the V12 improvement in this kind of situation, the normal tissue sparing was even more important.
So, with the new prescription strategy in Elements 1.5, you can now define your personal user specified heterogeneity. The need for tuning structures to introduce heterogeneity is eliminated. And, these four cases should show you that you can get better conformity index, a better gradient index, reduce the dose to immediate risk organs, lower monitor units and treatment plan complexity, and you have an improved V12. Thank you.
Another thing for me, is quite a situation. I'm out of the generation of brain scan, then I plan, and now elements. But, this is done simply, the triple plan on this [inaudible 00:02:44] vestibular schwannoma. This is another example. These are four tumors that we had, and one is the vestibular schwannoma, the other one is a cavernoma, brain stem. The other one is the small meningioma right down here, and this is another meningioma. You now can put in, like, simply for your dose normalization, your desired volume, tolerated volume, the dose, isodose line, 5%, volume 5%, and the dose. And we look then at the so-called conformity index, the [inaudible 00:03:28] index, which is in elements, and compare those with the elements cranial SRS 1 and 1.5. In all cases of these tumors, we did see an improvement of the conformity index.
Now, we look for the gradient index, which gives you an expression how much dose has spilled outside, and how much the dose, the gradient index, that means the dose [inaudible 00:03:54]. And, we did also see in all these cases an improvement of the gradient index. And, what we have in this kind of situation, we now can make full use of the so-called 4Pi Arc Optimization, and that provides automatic Cochlea Sparing. And, we don't need no longer to put in the so-called special structures to help on Cochlea Sparing. And, when we look at the Cochlea Sparing, there is full trajectory optimization, automation, the 4Pi, and you see that the cochlea dose can be brought down quite considerably, the mean dose, and the maximum dose. And, we are there now in the desired area that we want to have even on the, sort of, relatively complex cases close to the cochlea with the new element versions.
The brainstem sparing with the 4Pi optimization also helps us quite considerably on the conformity index in this kind of situation. When we look at the mean dose and the maximum dose, we also have been able to bring that down. But, here in this kind of situation, if you just go back, we aim, for instance, for maximum Cochlea Sparing in this kind of situation, and then the brainstem sparing is obviously not quite as good. But, if we deliver only 12 gray, this is not a problem. And, the Cochlea Sparing with the full trajectory optimization with the 4Pi, we have the cochlea mean dose, and the cochlea maximum dose for the brainstem as showed. So, we also did find that with this new way, this sort of treatment planning, we had a monitor unit reduction with the full trajectory optimization. And, we were able to avoid OARs, objects of risk in this, and for more complex structures. When we look at the V12 improvement in this kind of situation, the normal tissue sparing was even more important.
So, with the new prescription strategy in Elements 1.5, you can now define your personal user specified heterogeneity. The need for tuning structures to introduce heterogeneity is eliminated. And, these four cases should show you that you can get better conformity index, a better gradient index, reduce the dose to immediate risk organs, lower monitor units and treatment plan complexity, and you have an improved V12. Thank you.