Mindy Joo (00:04):

Good morning. Today I’m going to be presenting our initial clinical experiences with SGRT system. I’ll first give a brief background about our department at Innova Health and about the InBore SGRT system. I’ll talk about our SGRT workflow from CT simulation to treatment and finish with a couple patient treatment examples. So Inova is a health system located in Northern Virginia outside of DC. We have several hospital locations spread across the region. The Department of Radiation Oncology is part of the Schar Cancer Institute and has about five hospital locations across the system. We have 10 Linacs total. So that’s the C-arm as well as the ring Linacs. We also have speciality machines like CyberKnife, proton therapy, and extensive brachytherapy program. Currently, we have about 10 AlignRT systems, including eight C-arm systems for our photon therapy and proton therapy, or C Linacs and the proton therapy and to InBore SGRT systems for our health down and Ethos. So last year our Fairfax Medical campus got our Ethos. After all the commissioning and training, we went live treating patients in December of last year. We started with treating sites like the abdomen, pelvis, CNS, and extremities. Later on this year, we’ll be extending to other sites like the head and neck and lung. Within about one month of going live, we were treating more than 40 patients a day on that machine.

Mindy Joo (01:55):

So this is the InBore SGRT system for our Ethos, there are two sets of cameras. There are the ceiling mounting cameras you can see here, as well as the InBore ring cameras that you can’t really see in this from this picture. So the three external cameras are mounted on the ceiling, just like the c camera system. Those cameras point at the same Isocenter. And they’re usually used for initial patient setup. So once the therapist bring the patient in and put them on the couch, those cameras are used to position do the initial positioning for the patient. After that is done, the patient will be moved InBore for treatment positioning, and that’s where the InBore cameras come into play.

Mindy Joo (02:38):

So there are two cameras on the InBore ring and this ring can be removed using the knob on the bottom of the, the ring there. And those rings are used for patient monitoring during treatment delivery. I won’t be talking too much about the QA for the SGRT system.

Mindy Joo (02:55):

I just want to talk about bring up that the QA devices for the InBore system are the same as for the C-arm system. So there’s the play for daily QA and physics calibration, as well as the cube phantom. If you want to calibrate your MV Isocenter to the SGRT Isocenter.

Mindy Joo (03:18):

In terms of software interface, the invoice SGRT looks pretty much the same as the C-arm ones. So in the preparation page where a therapist usually import the patient, you can see like the plan, how the protocol and surface sets are laid out. It’s pretty much the same. In terms of treatment interface, the deltas are still displayed the same way. And on the top you can see what the plan and structures that you have there. One thing that is slightly different is on the bottom that you can see the setup and treatment options. So those are referring to the two sets of cameras for the InBore system. So the setup would be referring to the external three cameras in the ceiling for initial setup and the treatment are the ones inside the bore when the patient’s actually ready for treatment. Sothis allows the therapist to toggle between the two, depends on where the patient is and what you want to look at. Another difference with the InBore system is that it displays two sets. One is a set up Isocenter and one is a treatment Isocenter.

Mindy Joo (04:22):

And as I mentioned before, because of the two sets of cameras, the external ones are used for setup. So it looks at the setup Isocenter, and once the patient’s inside the bore, the InBore cameras will look at the uses, the treatment Isocenter.

Mindy Joo (04:37):

So our therapists have been active SGRT users for years. We use SGRT for about 90% of our patients from initial setup, DIBH to treatment monitoring. However, even with all these years of experience before our went live, our therapists were just having all these questions, like how are we going to deal with the two sets of cameras? How are they correlated? How are we going to set the patient up? Which one do we use? How do we move the patient while the patients are in the bore? I guess one of the most important question is like, do we need to change our workflow or make a special adjustment just because we have this import system?

Mindy Joo (05:21):

SoI wanted to talk about what our general workflow already is witchlike a TrueBeam SGRT system. So starting at CT simulation, patients are set up in a standardized setup with immobilization devices. At least one of the devices is indexed to the couch. Currently we still mark or tattoo our patients, so that would be done during CMT simulation. And then once the images are transferred to the treatment planning system dosimetrist will mark where those bb’s are. Set of localization point, we do have several TPSs. So we use RayStation and Eclipse. And now that we have Ethos, we also have the Ethos TPS. After the plan is complete and approved, we’ll be imported into the SGRT system and therapists will, you know, select their services and delineate their ROIs appropriately. And then at treatment delivery, patients will first be set up using the same devices, using the CT sim therapist will align the patient or the marks on the patient to the room laser. They’ll turn on the SGRT system, make any fine adjustments just according to what the SGRT system is telling them. And then once they’ll step out the room, make their imaging if needed and shifts and all that.

Mindy Joo (06:45):

So if we look at what our InBore workflow is like in terms of city simulation everything’s pretty much the same. We use the same devices set up positioning. Not much has changed per se. So therapists continue to place marks or tattoos andCT simulation. Once those are set during treatment planning, those dosimetrists will continue to set those localisation points. One thing is that localization point is going to be the setup Isocenter in SGRT. And once the dosimetrist make their plan, it depends on how, if there’s any delta shift between the bb’s and the fields. The field where the fields are, it’s going to be the treatment Isocenter. So once the plans are done, they’re exported from TPS to SGRT. Like I mentioned before, we do use multiple TPSs. So physics, we kind of check that all that information didn’t get lost while we’re doing all these transfers.

Mindy Joo (07:45):

And in terms of plan import into the SGRT system, it stays the same on the interface, is all pretty much the same. So we select which plans, which protocols and the structure set that the therapist would like to use. They will also draw the ROIs and the bottom image. I know I keep repeating this, but the main difference with the invoice SGRT system is that you will see the two Isocenters. So the gray one is the set up isocenter and the color of four one is the treatment Isocenter.

Mindy Joo (08:18):

For our InBore treatment workflow, therapists will first serve the patient using the marks and align those marks to the InBore laser. They will really focus on adjusting the pitch roll and rotation using the SGRT mainly because Ethos Couch has only three degrees of freedom. So the rest three degrees of freedom really rely on the therapist to manually adjust them before the patients send into the bore for treatment. So after that, they will move on to the translational deviations using SGRT and make adjustments. After all that is done outside the bore, the patient will be moved into the bore ready for imaging and treatment. And then at this time, therapists will change the SGRT camera from setup to treatment. The step out of the room acquire cone beam CT and make any imaging shifts accordingly. After that’s all done, they will take a new reference for this treatment session while the patient’s inside the bore.

Mindy Joo (09:23):

And now I’m going to just give a couple patient examples that we’ve encountered. So first one is a prostate patient here. Like many clinics out there, our therapists love the postural alignment feature of the SGRT system. So that’s like the first thing they turn on after patient’s on the couch. So first they use those three different cameras to get the patient to within those outline they will focus on the rotation role and pitch deviations first and really get those two as close to zero as possible. And then they’ll move on to the translational deviations.

Mindy Joo (09:58):

Another feature they like is this deformation. So it tells them exactly which part of the ROI they need to focus on to get that delta route close to zero. So instead of guessing like, oh, maybe patient needs to roll to the left, maybe the right hand needs to be up, you know, they can just look at this and be like, okay, mostly most of the deviations coming from the stomach, maybe patient’s a heavy belly breather and maybe we need to adjust the ROI. So it’s not just recording that.

Mindy Joo (10:28):

After all that adjustment is done outside the bore, patient is moving to the bore. And then on the bottom therapist will select the treatment cameras. So now we’re monitoring the patient inside the camera with those two cameras. One thing that is nice about the SGRT is that it gives the six degrees of motion while the patient’s inside the bore. Ethos does have a camera that will monitor the patient during treatment. However, that camera only gives us one directional shift. I think it’s lateral, so it doesn’t really give us that much information that helpful to us. So we actually have that turn off for our Ethos machine and we really use the InBore cameras to monitor the patient.

Mindy Joo (11:14):

After a cone beam CT is done for this patient and shifts were made, therapists took a new reference capture for this treatment while the patient’s inside the bore.

Mindy Joo (11:27):

One thing I wanted to talk about is the ROI selection. So, especially for pelvis and breast patients, there’s been different versions of ROIs out there. Currently, our patient’s therapists favorite one is the one in the middle. So that’s pretty much a similar ROI they draw for our C-arm TrueBeam patients. There will be other examples like the one on the left where the abdominal belt is like removed, so they were just focusing on the lateral hips. Sometimes for like patients who breathe really fast or something, that’s something that they might use to monitor patients then. Another variation is the one on the right where they really expand the ROI laterally and up around the hip. This one hasn’t been working for us as well because sometimes our hip patients or pelvis patient has fat lock backs around them in the pelvis region and the back actually goes high enough laterally to cover those parts of the body. So monitoring those parts not don’t really help us with setup or anything.

Mindy Joo (12:38):

So for this case the SGRT really helps us with pitch roll and rotation management. Since Ethos only has three good degrees of freedom, so this not only will reduce reimaging or any readjustment after a patient is like in the bore already and just hard for anyone to reach in and move the patient. ROI does play a very important role. So our therapists have like a preferred ROI, they like to draw that might work better for them or it might be patient specific that will really help them to position the patient. SGRT reduces overall setup time and also allows better patient monitoring during treatment delivery.

Mindy Joo (13:24):

The next example is a brain patient that we have. So for CNS and hand and neck patients, we use closed masks. And that kind of raises some questions because with closed masks, why are you really monitoring, why are you positioning, you’re the cameras are just looking at the mask. So then while we had our dosimetrist do is to ask them to control the patient without the mask so that when the therapists import all the DICOM info, we’ll have the surface with just the patient only without the mask on. So in this picture here, the patient was first set up on the table without any mask on. Therapists will select this patient only contour outline and use that to do initial adjustment. So they’ll use that to again, focus on the rotation roll and pitch like they will look at the screen and make sure that the chin is in the right, up or down or if the head is real to the left or right. And then after that, after the rotational, they will move on to the translational. And then at, at that point you’ll tell the patients, okay, we’re like, you’re aware, we want you to be, we’re going to put a mask on now.

Mindy Joo (14:41):

So that’s about the time when they put the mask on and translate the couch into the bore. Also, at this time they will change the treatment camera to change the camera to the treatment ones inside the bore. So with our hand and neck patients, the use of SGRT the use of multiple surfaces really help with initial patient setup because it allows us to use patient-only surfaces without any masks. SGRT also gives us less patient readjustment and reimaging after they’re in the bore.

Mindy Joo (15:16):

So overall our experience with InBore SGRT system has been a very high therapist satisfaction. There’s a reduction in setup time and reimaging dose. It also gives better patient motion monitoring while the beam is on. And that’s about it. Thank you.