Transcript
Dr. Tripuraneni: Good morning, thank you Dr. Panchiota [SP]. This is my first trip to Novalis Circle. Is Tim Solbeck [SP] somewhere in the audience somewhere? About six or seven years ago, I was trying to convince Tim, actually, to start to engage here as for practice application, and he was trying to talk me into doing Novalis Circle. And fast-forward eight years, he hasn't done the [inaudible 00:00:20.993] yet, and I'm doing the Novalis Circle. Thank you, Tim.
Male: [inaudible 00:00:25.786]
Dr. Tripuraneni: I want to recognize two of my colleagues who are in the audience, Dr. Faith Barnett and Richard Seier, the neurosurgeon and the physicist that I work very closely with. Dr. Barnett and my team have been working very closely together for almost 20 years. We used to do Gamma Knife almost exclusively for all of our patients, close to 70 to 100 patients a year for close to 10, 12, 13 years. And about six years ago, we got a brand new Linac and then we kind of moved everything, I think it was a matter of practical experience. For Gamma Knife, we were off-site and it takes about the whole day, whereas in the Linac department, it makes my life a whole lot easier, I can do a whole lot more things. And I think that the more software that's coming out, it's actually becoming easier and simpler to use Linac, even though Gamma Knife is equally valid. Two of my other colleagues, radiation oncologists, Dr. Chen and Dr. Lin, also use this equipment.
We had Elements first introduced to our clinic in June 2017. Since that time, approximately 125 contouring sessions were made, about 50 planning sessions, and about 30 multiple mets planning sessions. Probably the number of patients are more in the 20 range, because if somebody has multiple mets, each has 15 or 20, depending on they are located, we may end up using multiple isocenters. And I think in some patients, actually we have used as many as three isocenters.
The software. Elements software could be a standalone treatment planning software. And the particular hardware that we use, a TrueBeam STX. We use the high-definition multi-leaf column, with the 2.5 multileaf. And we use the ExacTrac with the dual generators. And we use the flattening free filter for mode, I think [inaudible 00:02:04.420] typically on 400 to 1400 monitor units per minute.
And one of the things I really like about the Elements software is the Smart Brush. I think it's actually especially useful in the metastasis. When you have a metastasis that has a rounder wall, you can just take three contours, basically axial, sagittal and coronal, and just drawing those and it fills in quite nicely. It works very well. In the past, we had to sit there and draw everything, our slice, 1-millimeter slices. And by the end of 10 mets, you could have spent about, easily, two hours, whereas with the Smart Brush, you can actually do that in 10, 15 minutes.
It doesn't work well with the post-op cases because actually they're irregular and it doesn't...I tried using it for vestibular schwannomas and the minute you have mets that are irregular, it doesn't work that well. But metastases, the normal metastasis, it works very well, so I like it. My physicist really liked it, actually, he uses the automated fusion, automated normal structures, contouring for my partner, Dr. Barkinspatt [SP], and template-based planning and arrangements right in there.
All right, he gave me the comparison. Rich actually gave me the comparison. Compared to the iPlan of the Elements, I think it's faster, it gave the level writing in there. I think probably the times that we spend doing things probably come down to about half. That has a bearing on how many mets we are going to treat. And typically for the ExacTrac, we use tolerances anywhere between 0.5 to 1-millimeter tolerance, and 0.5 to 1 degree. So we always cut 6 degree [inaudible 00:03:31.475] off of the brain. So when we take the ExacTrac measures, we block off the cervical spine and the mandible and use the cranium only as the target image guidance in there. And typically between each arc, we typically repeat the ExacTrac measures, and that's about probably no more than 30 seconds for each arc. And I think that you can give tighter margins.
Interestingly in our group, when I draw a metastasis, I think I draw it, probably I give extra 200, 300 microns per met that I see. My colleagues actually draw tight exactly what they see, and they give 1-millimeter margin for the GDV. So I don't know what is the right mode. And I don't think I have any more recurrences. And I don't think they have any more necrosis than I have right in there. In the imagining, initially we used to do, for ExacTrac, for each arc angle. In the past when we were doing multiple arcs for each metastasis, every time we used an arc planner beam. Now I asked that we move right there, we go ahead and take an ExacTrac, and then after, maybe in about maybe 20%, 30% of the patients here do a correction to get to less than a millimeter, less than a degree.
With the Elements software, what I liked actually, only last week, was that often you have one table angle and you are doing two arcs. You're doing a counterclockwise and a clockwise arc. And as for the old ExacTrac, we are actually using each arc, actually we are taking FIMs [SP]. And one of our techies asked us actually, "Why in hell are you doing the ExacTrac if you don't move the couch there?" And I kind of looked at myself and looked at my colleagues, and I said, "Yeah, it doesn't make sense. There is no need to actually repeat the ExacTrac measures if you don't move the table." So we changed our practice and that. So, you can do two arcs, both clockwise and counter-clockwise without having to take the ExacTrac as lying at the same table angle.
And single ISOs, I think it offers a slightly higher low to mid-dose normal whole brain, but a whole lot better than whole brain. Single ISO has the potential for missing the targets, especially if there are large patient rotations. I don't think that happens because we do the 6-degree frame correction on every single patient. Our treatment times are much faster. I will show you a few examples right in there. These are the typical patients that you see. I have four patients that I'm showing.
First one is a patient right here with the two mets next to each other. Easy plan, they are so close enough that you can go right in there. And we always look at the conformity index, new conformity index, and homogeneity index. I reached the point, at this point, you can almost not have to see the treatment plan, you can just look at the numbers and actually make your decisions. I guess, but you do go through and look at the axial and sagittal and coronal slices, but I depend on the dose-volume constants, and dose-volume numbers, actually, are a whole lot better.
Patient number two, four different mets and in fibular. You can actually see from there to there how the mets are getting smaller. Typical example of these patients is almost always you get a lot of control when you are treating these patients, depending on their primary site, typically when you follow them in three months, six months, nine months, or one year, they present with new metastasis. Having the progression of the metastasis when you have treated with the SRSPRK at a necrosis, a usually uncommon recurrence. It's the new metastasis that you're actually treating more and more.
Another patient with multiple metastasis, you can actually see right there. I think my [inaudible 00:06:46.065] actually has shown these pictures. I guess radiation oncologists love these color pictures. So, I'm going to pass over these quickly. And once again, my point is here that we are going to treat the single isocenter, multiple arcs, basically using a single isocenter. The conformity index and homogeneity index are basically both the same with no significant differences. Again, a comparative plan, you can actually see the metastases treated here are kind of getting smaller, and the metastases treated here, getting smaller right there. That's the usual plan that almost always that's what see in these patients. We are actually following more for actually new metastases that are developing.
This is the third patient I just want to illustrate, this is a patient that was treated in 2015. The patient was treated for seven arcs and each metastasis actually has...seven metastases, four arcs for each metastasis, that is 28 arcs. So the patient was treated in two days, and the first day, the patient was on the table for about one hour and four minutes. And I think second day, he was there for 1 hour and 22 minutes. That's about two-and-a-half hours to treat seven metastases. The patient actually is doing very well, lived long enough...You can see those volume constraints are reasonable. And these are the plans, you can see 28 different arcs.
The patient lived long enough into 2017 and presented with six new metastases. This time, the patient was treated with the single isocenter, with eight arcs, six table couch kicks, which I will show you, about six arcs, eight arcs. And what I want you to notice actually, the same 6 metastases, we were able to treat within 30 minutes and I think that's a major improvement for the patient to be able to look at the times. We don't look at the treatment delivery time, we look at the total time that the patient is on the table. Ultimately, that's what really matters for the patient.
All right, if you look at, again, the conformity index, homogeneity index, I think they're almost comparable. It's the low to mid-dose that you probably treat a little bit higher to the brain. I'm going to pass over these pictures quickly. I love these pictures here. Really nice to show to patients and also if you're doing a fundraising, these are great to show your potential donors to actually raise the money. All right, this is the final patient I want to talk about right in there. I think as the software is getting better, hardware is getting better, cognitively we're able to accept that we don't have to treat the whole brain. This is a patient that actually got treated, 19 metastases, I think with 3 different isocenters. The total time to treat these 19 metastases, about an hour right in there.
And about two weeks ago, three weeks ago, I think we can get out of this treating whole brain versus SRS. One patient, I think with a breast cancer presented I think with 20 or 25 metastases, small ones, in the cerebellum. And four or five metastases in the cerebrum. So, one of my colleagues came with a new idea. He treated a partial brain radiation therapy to the cerebellum. So, he used basically straight [inaudible 00:09:34.600] to treat the cerebellar region to include all the 25 metastases. And the five or six metastases in the cerebrum, he used the SRS right in there. I thought he was crazy, but looking back, I think he was smart, actually. And Dr. Bartlett had some trouble initially, but we all kind of bought into that. So, I think that is something that you could think about using it. Partial brain radiation therapy and also stereotactic radiosurgery, depending upon the number of metastases in the presentation. So the same patient that actually got the 19 metastases, almost 9 months after, the patient is doing very well, with all the metastases well under control, no vasogenic edema, neurovascularly he's functionally doing pretty well.
In summary, I think Elements actually opened up a whole new era of actually treating multiple metastases, faster contouring. For me, instead of spending 2 hours trying to draw 10 metastases, actually I can do, if there are 2 or more metastases, in about 15, 20 minutes I can draw the contouring. So, we spend a lot less time actually, doing the planning. And on the treatment table, they are spending a lot less time, actually, doing things right in there. As with these advances, I think we're able to treat more and more multiple metastases, but we just don't have long enough follow-up and not large enough number of patients are included to see what's going to happen to them. But like I said, in time, in due course, in one or two years, we will know a bit more.
And I always have to put in a plug for San Diego. This is San Juan Cabrio that actually came to San Diego I guess almost 400 years ago, first European. It's a new...what they call a potato chip. It's at Mount Woodson. It's about 500-feet drop. If you fall, you won't make it. And we do have the crazies in San Diego. And this is the [inaudible 00:11:10.824] the great park right in there. It's between my home and my workplace and I've hiked there probably a few thousand times. And if you ever happen to come to San Diego...and these are many good reasons to come to San Diego, to come and install BrainLab software and you can explore all these things. We have great sunsets. Thank you.
Male: [inaudible 00:00:25.786]
Dr. Tripuraneni: I want to recognize two of my colleagues who are in the audience, Dr. Faith Barnett and Richard Seier, the neurosurgeon and the physicist that I work very closely with. Dr. Barnett and my team have been working very closely together for almost 20 years. We used to do Gamma Knife almost exclusively for all of our patients, close to 70 to 100 patients a year for close to 10, 12, 13 years. And about six years ago, we got a brand new Linac and then we kind of moved everything, I think it was a matter of practical experience. For Gamma Knife, we were off-site and it takes about the whole day, whereas in the Linac department, it makes my life a whole lot easier, I can do a whole lot more things. And I think that the more software that's coming out, it's actually becoming easier and simpler to use Linac, even though Gamma Knife is equally valid. Two of my other colleagues, radiation oncologists, Dr. Chen and Dr. Lin, also use this equipment.
We had Elements first introduced to our clinic in June 2017. Since that time, approximately 125 contouring sessions were made, about 50 planning sessions, and about 30 multiple mets planning sessions. Probably the number of patients are more in the 20 range, because if somebody has multiple mets, each has 15 or 20, depending on they are located, we may end up using multiple isocenters. And I think in some patients, actually we have used as many as three isocenters.
The software. Elements software could be a standalone treatment planning software. And the particular hardware that we use, a TrueBeam STX. We use the high-definition multi-leaf column, with the 2.5 multileaf. And we use the ExacTrac with the dual generators. And we use the flattening free filter for mode, I think [inaudible 00:02:04.420] typically on 400 to 1400 monitor units per minute.
And one of the things I really like about the Elements software is the Smart Brush. I think it's actually especially useful in the metastasis. When you have a metastasis that has a rounder wall, you can just take three contours, basically axial, sagittal and coronal, and just drawing those and it fills in quite nicely. It works very well. In the past, we had to sit there and draw everything, our slice, 1-millimeter slices. And by the end of 10 mets, you could have spent about, easily, two hours, whereas with the Smart Brush, you can actually do that in 10, 15 minutes.
It doesn't work well with the post-op cases because actually they're irregular and it doesn't...I tried using it for vestibular schwannomas and the minute you have mets that are irregular, it doesn't work that well. But metastases, the normal metastasis, it works very well, so I like it. My physicist really liked it, actually, he uses the automated fusion, automated normal structures, contouring for my partner, Dr. Barkinspatt [SP], and template-based planning and arrangements right in there.
All right, he gave me the comparison. Rich actually gave me the comparison. Compared to the iPlan of the Elements, I think it's faster, it gave the level writing in there. I think probably the times that we spend doing things probably come down to about half. That has a bearing on how many mets we are going to treat. And typically for the ExacTrac, we use tolerances anywhere between 0.5 to 1-millimeter tolerance, and 0.5 to 1 degree. So we always cut 6 degree [inaudible 00:03:31.475] off of the brain. So when we take the ExacTrac measures, we block off the cervical spine and the mandible and use the cranium only as the target image guidance in there. And typically between each arc, we typically repeat the ExacTrac measures, and that's about probably no more than 30 seconds for each arc. And I think that you can give tighter margins.
Interestingly in our group, when I draw a metastasis, I think I draw it, probably I give extra 200, 300 microns per met that I see. My colleagues actually draw tight exactly what they see, and they give 1-millimeter margin for the GDV. So I don't know what is the right mode. And I don't think I have any more recurrences. And I don't think they have any more necrosis than I have right in there. In the imagining, initially we used to do, for ExacTrac, for each arc angle. In the past when we were doing multiple arcs for each metastasis, every time we used an arc planner beam. Now I asked that we move right there, we go ahead and take an ExacTrac, and then after, maybe in about maybe 20%, 30% of the patients here do a correction to get to less than a millimeter, less than a degree.
With the Elements software, what I liked actually, only last week, was that often you have one table angle and you are doing two arcs. You're doing a counterclockwise and a clockwise arc. And as for the old ExacTrac, we are actually using each arc, actually we are taking FIMs [SP]. And one of our techies asked us actually, "Why in hell are you doing the ExacTrac if you don't move the couch there?" And I kind of looked at myself and looked at my colleagues, and I said, "Yeah, it doesn't make sense. There is no need to actually repeat the ExacTrac measures if you don't move the table." So we changed our practice and that. So, you can do two arcs, both clockwise and counter-clockwise without having to take the ExacTrac as lying at the same table angle.
And single ISOs, I think it offers a slightly higher low to mid-dose normal whole brain, but a whole lot better than whole brain. Single ISO has the potential for missing the targets, especially if there are large patient rotations. I don't think that happens because we do the 6-degree frame correction on every single patient. Our treatment times are much faster. I will show you a few examples right in there. These are the typical patients that you see. I have four patients that I'm showing.
First one is a patient right here with the two mets next to each other. Easy plan, they are so close enough that you can go right in there. And we always look at the conformity index, new conformity index, and homogeneity index. I reached the point, at this point, you can almost not have to see the treatment plan, you can just look at the numbers and actually make your decisions. I guess, but you do go through and look at the axial and sagittal and coronal slices, but I depend on the dose-volume constants, and dose-volume numbers, actually, are a whole lot better.
Patient number two, four different mets and in fibular. You can actually see from there to there how the mets are getting smaller. Typical example of these patients is almost always you get a lot of control when you are treating these patients, depending on their primary site, typically when you follow them in three months, six months, nine months, or one year, they present with new metastasis. Having the progression of the metastasis when you have treated with the SRSPRK at a necrosis, a usually uncommon recurrence. It's the new metastasis that you're actually treating more and more.
Another patient with multiple metastasis, you can actually see right there. I think my [inaudible 00:06:46.065] actually has shown these pictures. I guess radiation oncologists love these color pictures. So, I'm going to pass over these quickly. And once again, my point is here that we are going to treat the single isocenter, multiple arcs, basically using a single isocenter. The conformity index and homogeneity index are basically both the same with no significant differences. Again, a comparative plan, you can actually see the metastases treated here are kind of getting smaller, and the metastases treated here, getting smaller right there. That's the usual plan that almost always that's what see in these patients. We are actually following more for actually new metastases that are developing.
This is the third patient I just want to illustrate, this is a patient that was treated in 2015. The patient was treated for seven arcs and each metastasis actually has...seven metastases, four arcs for each metastasis, that is 28 arcs. So the patient was treated in two days, and the first day, the patient was on the table for about one hour and four minutes. And I think second day, he was there for 1 hour and 22 minutes. That's about two-and-a-half hours to treat seven metastases. The patient actually is doing very well, lived long enough...You can see those volume constraints are reasonable. And these are the plans, you can see 28 different arcs.
The patient lived long enough into 2017 and presented with six new metastases. This time, the patient was treated with the single isocenter, with eight arcs, six table couch kicks, which I will show you, about six arcs, eight arcs. And what I want you to notice actually, the same 6 metastases, we were able to treat within 30 minutes and I think that's a major improvement for the patient to be able to look at the times. We don't look at the treatment delivery time, we look at the total time that the patient is on the table. Ultimately, that's what really matters for the patient.
All right, if you look at, again, the conformity index, homogeneity index, I think they're almost comparable. It's the low to mid-dose that you probably treat a little bit higher to the brain. I'm going to pass over these pictures quickly. I love these pictures here. Really nice to show to patients and also if you're doing a fundraising, these are great to show your potential donors to actually raise the money. All right, this is the final patient I want to talk about right in there. I think as the software is getting better, hardware is getting better, cognitively we're able to accept that we don't have to treat the whole brain. This is a patient that actually got treated, 19 metastases, I think with 3 different isocenters. The total time to treat these 19 metastases, about an hour right in there.
And about two weeks ago, three weeks ago, I think we can get out of this treating whole brain versus SRS. One patient, I think with a breast cancer presented I think with 20 or 25 metastases, small ones, in the cerebellum. And four or five metastases in the cerebrum. So, one of my colleagues came with a new idea. He treated a partial brain radiation therapy to the cerebellum. So, he used basically straight [inaudible 00:09:34.600] to treat the cerebellar region to include all the 25 metastases. And the five or six metastases in the cerebrum, he used the SRS right in there. I thought he was crazy, but looking back, I think he was smart, actually. And Dr. Bartlett had some trouble initially, but we all kind of bought into that. So, I think that is something that you could think about using it. Partial brain radiation therapy and also stereotactic radiosurgery, depending upon the number of metastases in the presentation. So the same patient that actually got the 19 metastases, almost 9 months after, the patient is doing very well, with all the metastases well under control, no vasogenic edema, neurovascularly he's functionally doing pretty well.
In summary, I think Elements actually opened up a whole new era of actually treating multiple metastases, faster contouring. For me, instead of spending 2 hours trying to draw 10 metastases, actually I can do, if there are 2 or more metastases, in about 15, 20 minutes I can draw the contouring. So, we spend a lot less time actually, doing the planning. And on the treatment table, they are spending a lot less time, actually, doing things right in there. As with these advances, I think we're able to treat more and more multiple metastases, but we just don't have long enough follow-up and not large enough number of patients are included to see what's going to happen to them. But like I said, in time, in due course, in one or two years, we will know a bit more.
And I always have to put in a plug for San Diego. This is San Juan Cabrio that actually came to San Diego I guess almost 400 years ago, first European. It's a new...what they call a potato chip. It's at Mount Woodson. It's about 500-feet drop. If you fall, you won't make it. And we do have the crazies in San Diego. And this is the [inaudible 00:11:10.824] the great park right in there. It's between my home and my workplace and I've hiked there probably a few thousand times. And if you ever happen to come to San Diego...and these are many good reasons to come to San Diego, to come and install BrainLab software and you can explore all these things. We have great sunsets. Thank you.