Streamlining Precision- The SGRT Direct-to-Unit Workflow

Today, we’ll be discussing how we’ve implemented a direct-to-unit workflow using SGRT on Ethos and how it improves efficiency and reduces treatment delays.

My name is Chinasa. I’ve been a therapist for about 11 years and joined UT Southwestern back in 2021. I’ve been on Ethos for over four years.

Hi, I’m Cherilyn. I’ve been a therapist for about seven years, and I joined UT Southwestern in 2024. I’ve been part of the Ethos team for only about a year and a half.

Just a little bit about UT Southwestern: we have two buildings, our E-Rock building and our A-Rock building. Our therapy team consists of about 60 therapists overall. Our E-Rock building houses our conventional machines, which includes VitalBeam and our Versas, and our A-Rock building includes more of our newer equipment, which is our Halcyon, Ethos, Unity, and Reflection machines. We also have CT, MRI, and PET imaging on-site, as well as CyberKnife, GammaPod, Gamma Knife, and HDR. We have a lot of “toys,” as you can see.

Today, we’re going to walk through how Ethos works, how SGRT integrates into our workflow, and then we’ll focus on the direct-to-unit approach, why we use it, and how it improves patient care.

Traditionally, patients go through simulation, then planning, and then treatment. However, in that workflow, there are a few challenges that cause delays between simulation and treatment, such as CT simulation availability, the need for re-simulation (if a patient had a procedure affecting their anatomy or mobility), insurance issues, equipment problems like a deflated Vac-Bag, machine availability, or doctor scheduling. All these challenges can lead to increased patient wait times. So, the question we’re trying to answer is: how can we reduce that wait time and lead to a better patient experience?

The solution at UT Southwestern is a workflow we call “direct-to-unit,” which means we are taking simulation and treatment and compacting them into one session at the treatment machine. We take that workflow and combine it with our adaptive therapy and SGRT. We are simulating, imaging, planning, and treating all in a single session, and SGRT helps us accurately guide that positioning.

The appeal of adaptive therapy is the technology behind it. Ethos brings imaging, planning, and treatment into one workflow, and what makes it unique is that therapists are actively contouring and making decisions in real-time. At UT Southwestern, each therapist that starts on Ethos goes through training with a credentialed adaptive therapist, our physics team, and MDs.

From a dosimetry standpoint, Ethos changes how we deliver treatment by bringing planning directly into the workflow. As adaptive therapists, one of our main roles is contouring OARs and some target volumes alongside our physicists. We have a variety of tools that help us refine structures, supported by AI features. For imaging, our Ethos was updated with HyperSight technology, which gives us CT-like image quality with scan times of about six seconds, along with features like metal artifact reduction.

At its core, what makes an adaptive machine unique is the ability to create treatment plans in real-time. During a treatment session, the system utilizes prior MRI or CT scans as supporting data to inform real-time planning. Once a plan is generated, typically in 10 minutes or less, we can use a “scheduled plan” (the original plan recalculated with the patient’s current anatomy) or an “adaptive plan” (a new plan re-optimized with current anatomy).

Moving on to the SGRT workflow on Ethos: SGRT guides alignment both outside and inside the bore. Once aligned, we scan, adapt, and proceed with treatment. The current workflow at UT with simulation involvement includes pre-treatment tasks: physics exports the patient’s DICOM from simulation into the Vision RT database. Next, the therapist and physics team work together to prepare the patient in AlignRT, verifying the patient’s name, MRN, birthdate, plan ID, protocol, and structure set. We also address whether the patient is free-breathing or in breath-hold and verify iso-coordinates. Lastly, we draw the ROI on the body while focusing on the target and stable areas around it.

On treatment day, if the patient has marks from simulation, we initially align to those marks. Vision RT is then used to verify positioning and make minor adjustments. This is also helpful if a patient has been treated for some time and lost their marks. If the patient is marker-less, Vision RT is our primary guide for alignment. All parameters—long, vert, pitch, roll, and rotation—are manually adjusted, and we utilize the postural video to confirm that alignment is correct. At UT, all of our breast patients are marker-less.

Once aligned, we send the patient into the bore to the iso-center. Using the in-bore camera, we verify that patient alignment is still correct. If the patient is in breath-hold, we check for reproducibility of that breath-hold. Once in-room setup is finished, we scan, adapt, choose our plan, scan one more time for verification, and then we treat. This whole process can take anywhere between 25 minutes to an hour, depending on the complexity.

Now, how do we include the direct-to-unit workflow? The first difference is that we determine which patients are eligible because they aren’t going through a separate simulation appointment. Usually, eligible patients are emergent cases, or those with deflated Vac-Bags, travel conflicts, or all breast patients at UT Southwestern. Once determined, the therapy team performs pre-checks, including verifying consent and insurance approval, ensuring we have the appropriate devices, and checking that our base treatment plan—which is a reference designed from a previous scan—is good.

Then, physics imports a previous scan from the patient into AlignRT for us. We verify the information in AlignRT and Ethos and draw our ROI. On treatment day, the biggest difference is that we are actually doing simulation at the machine. Patients have no marks, no devices. Vision RT is our main guide for getting to iso.

Using the example of a whole brain case: we use Vision RT to get to approximate iso based on the previous CT. Then, we use Vision RT again to ensure positioning is good, looking at pitch, rotation, and roll, then we draw our dots on their face and make the mask. For a pelvis case, we use Vision RT to get to iso and make pitch adjustments to the pelvis by adjusting elevation in the legs. For a breath-hold breast case, we can get that Vision RT reference in that moment by having the patient do three practice breath-holds.

What are the benefits? The biggest impact is patient wait time. We are reducing the time between simulation and treatment from days to just an hour. Typically, emergent cases can be scheduled within three days, but this direct-to-unit process can be done in an hour on our machine, allowing us to do it all in the same day. This also helps if a Vac-Bag becomes deflated; instead of a new simulation appointment, we can fix it right then and there. During a recent downtime of our CT scanners, using Ethos helped us keep our patient volume and throughput stable.

Early results are encouraging. Direct-to-unit treatments are averaging under an hour, with brain cases and free-breathing breast cases being the fastest. We have seen clear improvements in workflow efficiency and meaningful reductions in patient wait times.

Although our sample size is limited, the early results are encouraging. We are creating a better patient experience with fewer appointments and less waiting. As we continue to grow this process, our focus will be on expanding patient selection and incorporating more data-driven decision-making.

 

 

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