Our Experience with V8.0 (Varian)

So I’ll go through a little bit about Beam Guide and then some case studies that we’ve found it useful on.

We had the system upgraded on the 6th of March. Our previous version was 6.3.2, and we went to version 8.0, so we were an early test site for this release. It was a major release where we had a lot more data and patient information that needed to be transferred across, so it took a two-day process over the weekend.

The main features were Beam Guide and Auto ROI, but as I said, we’ll focus on the Beam Guide part today in the session. We then had more of an update, really, to version—we’re now on version 8.1.1. This was more about listening to the feedback from the early implemented sites and doing some minor software changes.

So Beam Guide, it’s using an overlay of the planned radiation field, so the MLC position. It merges that whilst you’re in Postural Video mode. So it kind of is complementing a setup. It doesn’t replace your imaging; it’s giving you that virtual light field. The huge benefit that we’ve found for other patients is that you can see that exit dose, which you wouldn’t be able to see on a light field necessarily. So there’s a nice case example coming up where that was incredibly useful for us. But yeah, so it’s something to complement setup, and it’s much easier on things.

VMAT plans can be a little bit tricky because you see the whole of the irradiated area. So we’ve found it most useful on things like tangential breast, but it is really helpful to look at chin position on an IMC VMAT plan, too.

How we integrated it within our workflow: we weren’t quite sure how exactly it was going to fit within our workflow, but we use it during the initial setup phase, just checking that’s… and you can toggle it on and off. You can select various fields that you’d like to look at. It can help you make those real-time decisions before you deliver any verification imaging, so it can help support problem-solving prior to imaging. Again, we’ve got some nice examples of that where repeat images and things have been saved by using the Beam Guide.

After acquisition, the white lines still remain at the isocenter position. So for the majority of patients, because we’ve applied a shift based on the soft tissue, we toggle the Beam Guide off. There’s been a couple of patients where we have checked field with the understanding that the patient’s in a slightly different position, but it can give you that gross check.

So I’m just going to press play on here. This is our first example of a breast patient where, during the setup stage, we noticed that the patient had swelling. So I will just pause it when we zoom in slightly. I don’t know if you could see that the swelling was outside of the Postural Video outline. You can see the breast tissue just under here is much clearer, obviously, when you’re actually using it in the room, but you can see on this white line that we were coming much closer to that border. This is something that you can obviously check on your field borders as well, but at the time when you’re making small adjustments to the patient’s position, you don’t want to have to keep moving the gantry to the medial and the lateral field to check. So it speeds that process up slightly, so you can make a decision and then do your final checks if you want to using your actual treatment field light.

The patient did have some roll as well, so we tried to roll the patient slightly to improve position. This patient then did get assessed by the dosimetry team just to make sure the coverage wasn’t impacted, but we wouldn’t have seen that coverage was so tight just based off a verification image. So it does give you that confidence, really, before you start delivering treatment that any swelling or any changes to the breast tissue, that it’s still covered.

This is another really interesting case. We had a palliative breast fungating patient. She had a fungating breast tumor. She came for her CT scan. She was in a VAC bag with limited arm movement at that point. But come day one, when she came to start, how the tumor had progressed, it meant that her arm position was even poorer than it was at the scan. We used Beam Guide because we knew that she couldn’t maintain—she couldn’t put her arms in the same planned position. We used Beam Guide to position the arms to make sure that the hand was out of the treatment field.

We could see the exit dose, which we wouldn’t have been able to see using the field light. We could see there was exit dose on the fingertips, and we were able to reposition her arm to get that out. On this particular fraction, whilst in between us setting up and imaging, she relaxed her hand down. So what you can see in the top corner here is her fingertips from where that had dropped into the treatment field. We saw the image, we saw there was something odd at the top of the image. We then switched Beam Guide on and could see that her fingers were receiving exit dose. Then we used the Beam Guide to reposition her hand out of the way of the exit dose. We didn’t then need to do any repeat images to confirm that it was out of the way, because we were confident that that was demonstrating the position that was needed for treatment.

We then, for this patient, did toggle it on during treatment just to confirm that her hand didn’t drop in again. This is one of the only times where we would use it during treatment. Even though we’d done slight shifts, we were confident at this point for this patient just to confirm that the hand wasn’t in the way of the treatment field.

This saved this patient going back to be replanned because we were able to use SGRT and Beam Guide to optimize her treatment and make sure that we were still delivering it. But it also meant that she wasn’t on the bed for too long, because we could make these decisions with the click of a button rather than having to go in and check field lights. And as I say, you wouldn’t have seen that her fingers were receiving exit dose anyway with the field light.

We had another palliative patient where they were in abdo, but what was scanned all looked exactly the same. It was just like one column almost when you’re looking at Postural Video. Day one, when you have no tattoos, these patients can be quite tricky because you don’t necessarily know where they are on the bed. AlignRT was struggling to detect the patient’s contour; it wasn’t giving them any numbers. It knew the patient wasn’t quite in the right position.

So what the radiographers did is they opened up external beam planning. They could see where the beams were supposed to be going on the patient’s abdomen. They switched on the Beam Guide and could see that they were currently in the wrong position for the patient. So they adjusted the long so that it looked sensible. By this point, SGRT had detected the patient and picked them up, so then they were able to continue on with treatment.

It reduced an error in us setting up to the wrong position and reduced any kind of repeat imaging, because we were able to make these assessments prior to delivering treatment. So it can be a really good value tool to give you that confidence when you’re unsure about your beam geometry and where that dose is going, particularly for those patients where it almost looks like one column and you’re not sure what the long position is.

We found additional applications for clinical value for Beam Guide. One is that you can check your breath hold, and you can visually confirm that your field is covering to make sure that they’re still breathing within that… we’ve got a little margin around. I can’t think what it is off the top of my head right now, sorry.

The other thing is that it gives you that visual feedback to be able to perform corrections on setups before taking that image. It can help improve the patient experience, particularly that patient where it prevented her having a rescan—with a palliative breast patient, where we were able to get her treatment in as soon as possible, and we weren’t having to repeat image. Her setup was incredibly quick compared to what it can be for that group of patients at times.

This is a little video of us doing a setup on a breast patient and using Beam Guide. At the moment, setup with patients in free breathing. You can see a little bit of flash on the chin, so just lifting that up and out of the way. We’re now flicking to the breath hold surface. We’re getting the patient to breathe in. Once we’re in breath hold, we then send everything except overt across.

This is our real-time setup with the use of the Beam Guide. They’re just going to optimize the arm position better there, because you can see there’s a bit of a gap on Postural Video. Getting in one last time just to double check everything, lifting that chin again up out of the way. Then we check FSDs daily and the deformation.

We can see a lot of potential with this technology. What we’re hoping to do—and we’ve had a good thought about how we could use it—is to optimize bolus positioning. Our center uses bolus a lot, so anything we can do to simplify that workflow is going to be to everybody’s benefit. So we’re in the process of thinking about how we could use Beam Guide to help with placement of bolus or checking bolus position during the setup stage.

It’s also about how we can integrate it into our clinical workflows. How do we embed it more within our current processes? Because we’re just getting our heads around it, really, and seeing its clinical uses, but it’s then how do you make it more of an official format for staff?

We’re also expanding our case study library, so the staff will let us know if they’ve found an interesting case where they’ve found it useful or they’ve not, and we can have a look at that. Again, we’re hoping that we can use Beam Guide to strengthen our workflows and improve that consistency, and then reproducibility in setups.

So it’s all about identifying our future development needs and capturing that user feedback to refine how we’re going to use it in the future.

*This transcript has been AI-generated. Contact us at secretary@sgrt.org if there are any issues.