Lauren A. Dalvin, M.D. , an ophthalmologist with subspecialty training in ocular oncology at Mayo Clinic in Rochester, Minnesota, performs a placement of a plaque radiation device for a patient with a newly diagnosed choroidal melanoma.
So today we're treating a steroidal melanoma using plaque radiotherapy. The first step of our surgery is to do a content type of polygamy. And because the tumors infra temporal, we're going to try to expose just our lateral and inferior rectus muscles. And I like to keep my parada me nice and tight to the limb bas that makes for an easy closure down the road at the end of the case. So now we're going to give ourselves some nice exposure by spreading in the quadrants between the muscles with our curved stevens scissors. And we want to make sure we get nice and deep so that we dissect the teen ins away from the globe. This will again give us a nice working space and we're dissecting on both sides of both the lateral and the inferior rectus muscles. So now we're going to be hooking each of those muscles using our gas muscle hook. And this allows us to manipulate the eye during our surgery to get adequate exposure to see where tumor is. We use a silk suture to implicate each of our muscles here and this is going to give us a nice control over the globe during our case. So the next thing we're gonna be doing is we're going to be inspecting this infra temporal quadrant. We'll use our escape ins to make sure again that we have good exposure in this area. So as you can see we have good visualization of the square in this area and this is where our tumor should be located. So the next step we're going to do is called trans illumination. And this we use a light pipe and shine it through the eye. And when we have a large anti really located pigmented tumor, we should be able to see a tumor shadow that helps us mark out the tumor borders. Okay, so as you can see, we actually get a really nice shadow here. So we see a dark shadow. So the white school era allows light to shine through it. But the pigmented tumor is dark so no light passes through. We actually get a shadow in that area. So we're going to dry off this area and we're going to be marking the borders of our tumor. This tells us where to place the plaque. And generally I mark the anterior tumor border and the lateral margins of the tumor. It's pretty hard to get to the posterior margin of the tumor. But this will be sufficient to let us know that our plaque is going to be in good position. We're done with our trans illumination steps. So now we're gonna be using our dummy plaques. So this is actually clear and allows us to see through the plaque. And that's going to be very useful since we've been able to mark out our tumor borders. And you can see that we can see our marks that we made around that tumor shadow within this clear plastic dummy plaque. That lets us know that we're covering all of our margins of the tumor that we saw from our shadow. So our eyelids are where we actually aim to suture our plaque to the square so that we hold it in place during treatment. So I like to use three stabilization points. So we have six eyelets, total suture to three. So we've made nice tiny marks there. So now we'll remove our plastic dummy plaque and we're going to be placing our sutures that will be used to hold our plaque in place. And when I'm coming out with my needle, I'm always staying parallel to the globe. That's very important. If you sort of round up and dig the tail of your needle into the square, you can actually perforate the square that way. So I'm very cautious. So now we have all three of our sutures in place and we're gonna take our metal dummy plaques are metal dummy plaque is used because this is opaque on our ultrasound. So when we do ultrasound will actually be able to see our metal dummy plaque slide this back into that infra temporal quadrant there and we're going to align our islets again. We're going to touch this only with our instruments were not going to touch this with our hands because it's radioactive. And my assistant is going to be ready with a nice exposure for me to place this exactly in that infra temporal quadrant. That's going to be an excellent position. We're gonna take our needle driver and we're just gonna put each of these sutures in place. Here's our third and final suture. So we're gonna go ahead and start tying these down nicely. So once we've got this tied down last needle back and we're going to again rotate the eye infra temporarily. Now we're going to place some gel on the surface of the eye. So now we're done using our muscles to manipulate the I we can go ahead and cut our implications sutures there. So on monday we placed this radioactive iodine plaque infra temporarily to treat a Kuroyedov melanoma. And it's been in place with a big patch over the eye since then. So here we are on friday. And all we get to do today is cut this plaque off so that this gentleman is free from radio activity. And then we're going to watch the tumor shrink down into a flat scar over the next several months. Okay. Yeah. Yeah.
