Ella Horgan
Radiation Therapist
Prince of Wales, Sydney, Australia

Ella Horgan (00:04):

Hi everyone. My name is Ella. I’m a radiation therapist working in the Prince of Wales Hospital in Sydney. Today, I’ll discuss with you a case study titled Adapting to Patients’ Limitations. This case study discusses a head and neck cancer patient with multiple limitations, making his treatment a little bit challenging. However, with the use of SGRT along with daily Cone Beam CTs, we were able to treat this man completely massless, all while making very minimal moves with our imaging scans.

Ella Horgan (00:33):

This patient is a 91-year-old man diagnosed with a preauricular metastatic squamous cell carcinoma on the left side. After careful consideration, the radiation oncologist determined the most appropriate treatment approach would be radiation therapy targeting the left parotid bed and upper neck. However, this case presented significant challenges due to the patient’s numerous comorbidities including chronic obstructive pulmonary disease, a high body mass index, and increased risk of falls due to instability and vertigo. These factors made the treatment plan more complex and required careful management. As you know, the standard immobilization for a head and neck cancer patient would be a five point serum plastic mask, a comfortable headrest elevating the chin and a knee block supporting the knees.

Ella Horgan (01:22):

Some departments even use an open face, head and neck mask. However, due to the patient’s comorbidities, a modified immobilization approach was necessary. Given the severe vertigo he experienced, he was unable to lie flat. As a result, the patient was positioned on an elevated breast board with a 20-degree tilt. A VAC bag was utilized to provide head support and a knee rest was placed under the patient’s knees for comfort. Micro port tape was applied as an optional aid in the setup, which the patient agreed to as it had provided additional stability and reassurance, ensuring that he remains still. An IMRT plan was developed for this patient with the Isocenter strategically positioned 10 centimeter inferior to the planning target volume to avoid the risk of collision. The dose constraints for the organs at risk were all within the specified tolerances outlined by the EVQ guidelines. A 0.5 CENTIMES meter, CTV-PTV margin was decided by the radiation oncologist. This margin size is in line with the recommended guidelines for standard head and neck treatments using a mask. A study by Eser Al looked at the setup and fractional motion of using SGRT for head and neck cancer patients. The results of this study found the massless setup with SGRT and Cone BEAM CT were just as accurate as treatment with a mask. SGRT showed that inaction motion was gradual during the treatment and the CTV-PTV margin correcting for the inaction motion was 1.7 millimeters per OSUs treatment. This study agrees with our 0.5 centimeter margin being sufficient for accurate PTV coverage.

Ella Horgan (03:09):

After the plan was exported to SGRT, a region of interest was created. This region of interest included the nose, cheeks, chin and neck. After the plan was exported to SGRT, a tolerance of 0.2 centimeters was set across the translations and two degrees per rotations. The setting for beam control was turned on for the treatment to ensure any movement greater than 0.2 would pause the treatment. The patient was prescribed 48 gram and 20 fractions at 2.4 gram per fraction. SGRT was used for the patient set up and during treatment, a Cone Beam CT was created and used daily to ensure accurate patient positioning. A dummy run was performed on the Linac prior to day one to assess if collisions would occur. The result of this determined that HEXA pod could not be utilized, therefore, only translational shifts could be applied during treatment for a patient set up. Translations and rotations on SGRT were corrected for. The video function was also used daily to ensure the patient’s head and shoulders were in the correct position. After the patient was positioned on day one, the gantry was rotated around the treatment couch with imaging panels extended to assess whether the gantry blocked the cameras potentially causing the SGRT to flicker. This dummy run showed us that the cameras were not obstructed.

Ella Horgan (04:48):

Once this was complete, a Cone Beam CT was required. Due to the Isocenter positioning. The superior part of the PTV was caught from our imaging scans. This is another challenge experienced during treatment. However, as you can see from the Cone Beam CT above, there were enough slices to make a good clinical judgment on the patient’s positioning. All translations were then applied. The imaging panels were put away to ensure the SGRT cameras were not blocked during treatment. A new reference capture was taken to monitor the new acquired position and the SGRT response button was turned on. The results from the 20 fractions are shown here on fraction one, three and four. The largest translational ships were 0.6, 0.8 and 0.6, respectively. As you can see from the line graphs, the shift was decreasing. The shifts are decreasing from fraction four onwards. These shifts are 0.5 centimeters and reasons for this could be consistent staff treating him daily, understanding his setup, and altering the region of interest as necessary after the first few fractions. However, with the help of SGRT for set up, these post-imaging shifts were minimal. While the patient’s treatment was ultimately successful, several challenges were encountered throughout the process. As discussed previously, the Isocenter positioning presented some difficulties in reviewing the Cone Beam CT as certain slices of the PTV were missing from the image. Furthermore, due to the inability to use the HEXA pod, rotational shifts could not be made, which added complexity to the treatment setup. Additionally, the patient faces challenges in getting on and off the treatment couch. This issue was overcome by the presence of additional staff members during treatment, ensuring the patient’s safety and comfort.

Ella Horgan (06:44):

After completing the patient’s treatment, it was interesting to evaluate the result of the Cone Beam CT scans and reflect on the advantages and drawbacks of massless treatment. The benefits of massless treatment include enhanced patient comfort, cost savings for the department, reduced time spent on mass creation, alleviated patient anxiety and greater flexibility and positioning. However, the drawbacks include the need for monitor closer monitoring of the patient, specific patient criteria for eligibility such as pediatric cases, and the potential for longer setup times. In conclusion, by using SGRT, we successfully provided effective treatment to a patient with numerous limitations, all while eliminating the need for thermoplastic mass for immobilization. Importantly, the CTV-PTV margin remained consistent between the massless approach and the traditional mass-based method, ensuring the treatment precision was maintained. This approach highlights the potential of SCRT and Cone Beam CTs as a reliable and effective alternative to conventional immobilization techniques, especially with patients with treatment limitations. Thank you.

Karl Jordan
Senior Physicist
St Vincent’s Private Hospital, Dublin, Ireland

Tags: Accuracy, Workflow optimization, Efficiency, Implementation, time saving, clearance mapping, planning , MapRT, coplanar

Wendy Tisue, MBA, RT(R)(T)
Mayo Clinic Cancer Center

Michael Tallhamer
Chief of Radiation Physics
AdventHealth Parker, USA

Hannah Nayee
Project Development Radiographer, Royal Surrey NHS Foundation Trust, UK

Samantha Allison
Lead Pre-Treatment Radiographer, Royal Surrey NHS Foundation Trust, UK

Gail Anastasi
Principal Radiotherapy Physicist, Royal Surrey Cancer Centre, UK

Tags:Deep inspiration Breath hold, Voluntary breath hold, Breath hold, sim

Stephanie Hoff, BS, RT(T) (ARRT)
SSM Health St. Mary’s Hospital-Janesville

Stephanie Hoff (00:04):

Hi everyone, I’m Stephanie. Today I’m going to talk to you about my clinic’s workflows on using electrons for both clinical electrons and planned electrons and some benefits we found to using AlignRT.

Stephanie Hoff (00:19):

So some quick disclaimers before I get started. My center is a center of excellence for AlignRT. All information I provide with you today is just based on our clinical workflows and we did utilize recommendations from AlignRT. These recommendations that we use are available to anyone who uses our systems.

 Stephanie Hoff (00:41):

So our agenda today is first to start talking about our clinical workflow of clinical electrons. Then we’ll move into our CT planned electrons and we’ll finish off with some benefits and advantages. So a little bit about us.

Stephanie Hoff (00:58):

We are located in Janesville, Wisconsin. If you’re not familiar with Wisconsin at all, Janesville is located about 15 miles from the Illinois border. SSM Health is a Catholic-based hospital. We are not-for-profit. We’re a community-based hospital and we have about 50 bed units. We’re on the smaller side.

Stephanie Hoff (01:27):

Our department is one of three radiation oncology departments in the county. We are the newest we opened in 2016. We utilize ovarian TrueBeam linear accelerator, GE CT simulator and the AlignRT camera system. We achieved our center of excellence from AlignRT back in 2020. We’re staffed with one radiation oncologist, one nurse, one physicist, three radiation therapists, and our dosimetry services are actually provided by one of our sister sites in Madison.

Stephanie Hoff (02:03):

So let’s start talking about clinical electron setups. So I’ll have to apologize if you’re familiar with using this. I’m going to take you through, click by, click on how to do this. So bear with me if you’re familiar with it. So if you’re familiar with the system, you know that this is the main screen and when we’re doing a clinical sim, we don’t have that CT data set. So it’s a little bit different with getting that patient imported into the system. So in order to do that we’re going to go to patient browser. Once in your patient browser here at the bottom right hand of the screen, we’re going to select on add patient and a little box is going to click come up here and we’re going to put in all of our patient information. So first name, last name, patient ID, patient ID for us is that ARIA number, gender date of birth, and then we’re going to click save. Once we have all that put in, our patient is now in the patient browser. So we’re going to go back to that patient browser and we’re going to find that patient that we just put in. We’re going to right click on them and we’re going to hit treat without plan. Once we hit treat without plan, it’s going to pull up this box here saying, are you sure you want to do this? You don’t have an imported DICOM plan? Yes, we want to proceed, we’re going to create our own plan. So we’re going to type in plan name for sake of consistency. The plan name that we type in is the exact same plan name that we put in on TrueBeam just for sake of consistency. And that protocol you select is whatever you’re going to be treating. So if you’re treating something in that face area, probably going to want head and neck treating something on the arm or leg. Most likely you’re going to choose extremity. At this point we can now bring that patient that we’re going to be doing into the room because we’re ready for that clinical sim and we’re going to set them up per the MD order.

Stephanie Hoff (03:55):

Once that patient is set up per those instructions and we have all of that necessary information wrote down all the pictures taken of your field light we’re then going to move back to the AlignRT and we’re going to take a reference capture. In order to take a reference capture though we’re going to take that electron cone out. We’re going to take that electron cone out so that we have more surface area of that patient and we’re not blocking anything when we take the reference capture. We want to make sure that we’re clicking on this in future session. Otherwise, when you go back into this patient on that first day of sim, if you don’t click this in future there’s going to be nothing in there for you. Similarly, we also found throughout our workflow with gantry angle, if that gantry is super rotated, we found it best to make sure that gantry is up at zero when we’re taking that reference capture. Same thing, just not blocking any of the surface area needed for that ROI throughout trial and error. We’ve also learned when patients have a couch kick, we’re going to take two reference captures, one at that treatment angle and then again at zero.

Stephanie Hoff (05:04):

Once you have all of those necessary reference captures that you want to use we’re going to go back into preparation. There’s two ways of getting back there. If you’re still in the room doing this, you can click up on that top blue bar back to preparation, otherwise you can go back to patient browser, click on your patient and go into preparation that way. This is where we’re going to add all of those ROIs for our patients. So we’re going to right click on the SGRT we had and we’re going to edit them and add in an ROI. Once we’ve done that, the patient is ready for the first day of treatment.

Stephanie Hoff (05:40):

When we’re importing a clinical sim and patients have couch kick, it’s a little bit different. AlignRT doesn’t recognize that in the couch button. So there when you click on couch it’s just going to give you zero. So in order for us to know which one is at couch zero and which one is at that couch kick, we, when we put in those ROIs, that’s where we type in. If couch is at zero or if couch is kicked, we can keep it clear. So on your left hand side of the screen you can see that reference capture we have there. Gantry is at zero, tables at zero and then on the right hand side of the screen you can see reference capture gantry zero and tables at 353 and then displayed in the middle of the screen is right where you can see where those ROIs are at.

Stephanie Hoff (06:25):

When we bring that patient in for setup our processes to first start setting them up with gantry at zero and table at zero. Once all of those deltas are in the green, we’re then going to rotate that patient to the treatment couch kick and same thing, get all of those deltas to in the green. Once we’re there then we’re going to put in that electron cone and fine tune from there. So make sure your field like looks the same as those pictures you took on the first day. Verify that SSD.

Stephanie Hoff (06:54):

Once we have all of that then we’re going to take a reference capture with that cone in. Backing up a little bit to switch between those two SGRT, you’re just going to click on that middle arrow there to switch between your table at zero and your couch kick.

Stephanie Hoff (07:15):

So when we take those reference captures when that electron cone is in, you can see that it kind of blocks some surface area. So there’s two different options you can do if that’s a consistent ROI that you can be using. You can have two ROI so you can switch back between, you can use your setup ROI that has that full setup, not blocked with the electron cone and then another one that is adjusted for when that electron cone is in. If it’s not consistent, you can just kind of adapt on the fly. So in order to do that you’ll use that right carrot on the side of the screen and you’re going to adjust ROI. If you do use Postural Video, which I do recommend for electrons you will have to toggle back over to surface though in order to edit your ROI.

Stephanie Hoff (08:01):

So now we’re going to transition into CT planned electron setups. The process for CT planned electrons is pretty similar, just a little bit of a different import process. So you’re going to import this patient the same way you do for photons. So same thing here. You’re going to start with your patient browser and you can filter out to new plans received on the left-hand side of the screen, and when you find the appropriate patient that you want to import, we’re going to click preparation.

Stephanie Hoff (08:32):

So this is where it’s a little bit different. So now you’re going to see that DICOM plan and import it just like that photons. So we’re going to select the protocol that we want to use for them and then we’re going to draw our ROIs. As you can see here, I have drawn two ROIs for my patient. The first one that I drew is going to be our first treatment setup. So it’s the main one you see displayed here. So it’s going to be the full face. We’re going to use this one before we put the electron cone in and then I drew another one. I’m assuming that once we put that cone in the left side of that patient’s face is going to be blocked by that cone. So I’ve just drew the ROI on the one side of the face. This patient also utilizes couch kicks, but here you can see since this is a DICOM plan, AlignRT recognizes that. So you can switch through the couch kicks a little bit differently on this one so you can see zero and 320. When we bring this patient in the room, we’re going to first set up to table zero, get all those deltas in the green, then rotate to that couch kick set them up, get all the deltas in the green and then put that cone in.

Stephanie Hoff (09:53):

Once the radiation therapists are satisfied with their setup, we take a reference capture with that cone in and here you can see I’m showing you that we’re going to switch to that other ROA drone that we drew with just one side of their face here and then there’s a good picture comb blocks that side of the face. But the ROI that we drew gives us a good representation of any movement that patient would make.

Stephanie Hoff (10:22):

Breath-hold electrons. Once we gained confidence in our process with using AlignRT, we were then comfortable with using it for breath holds. So the import process is pretty similar with breath hold electrons. Same to like with your DIBH. So when you’re importing that, you’re going to have a free breathe and a breath hold and the process in the room is fairly similar besides once you have them where you want them for with their breath hold, we’re then going to put in the electron cone while they’re in a breath hold we’re going to verify that field light and we’ll verify that we’re at that correct SSD. If we need to make any adjustments slightly, we can make those adjustments there and we’re going to capture a reference with that cone in. You may have to alter your ROI a little bit. Once that cone is in, you do want to make sure that you have enough of that abdomen though so that you’re still reading that accurate breath hold. This patient also utilizes full field bolus, so in addition to making sure they’re in that good breath hold, we then did another extra breath hold, put that bolus on them and then recaptured with bolus so that we could monitor for surface guidance.

Stephanie Hoff (11:37):

So advantages and benefits. At St. Mary’s. Janesville, our team felt that SGRT met our electron setups more simplified. Our team feels that utilizing SGRT setups allows us to see those misalignments much quicker. We actually have a patient on treatment right now we’re treating a nasal ala and AlignRT really helps us get that role really particular before we get that mask on them. And fine-tune role plays a crucial role in her setup. If we don’t have the role accurate then we have flash on the opposite side of her face. It really helps us get that pretty accurate. We can monitor patient movement. I don’t know about you, but I feel like most of my electrons are 85 plus years old. So it’s really nice to know that they don’t move once we’re walking outside of that room. And then we were able to implement breath hold electrons. Lastly, it added additional verification for us. We had an incidence at our center where we had an issue with documentation. The documentation was put in that the patient was set up clinically on that clinical sim day at an extended distance, A 1055 SSD. The patient was in fact not set up at 1055, they were at 100.5. So with our pictures that we took on vSim day and the additional AlignRT, we could see that we gave dosimetry the wrong SSE to plan the patient on. And we were able to kick that plan back to planning.

Innovating with the clinic: SGRT for SIM
Mike Tallhamer DABR, Chief of Medical Physics
Centura Health

Tags: Accuracy, Workflow optimization, Efficiency, motion management, Implementation, SimRT

Ryan Hecox, MS, DABR
Lead Medical Physicist
Intermountain Health – Canyons Region, Provo, UT

Tags: Accuracy, Workflow optimization, Efficiency, motion management, training, time saving, Implementation, AlignRT, DIBH, Markfree,Markerfree, Markerless, tattoo and markfree,tattooless, sim