So the next 20 minutes I'll try to talk about integrating interoperative MRI into mapping and most of this was primarily performed by me and a couple of my colleagues so without further ado there's no no disclosures and at MD Anderson we have in 1.5 Tesla it's called brain suite and clearly we've had it now for just under 10 years done a lot of cases what I've been using it more recently is to integrate cortical sub cortical mapping in terms of mapping we clearly have tools which are all platinum based especially for the needles and the and the grid so clearly that becomes a non-issue in the interoperative setting and so when we published our first first set of results these were this was back in I believe 2010 we had about 40 patients we looked at basically more of a proof of concept but also to see see how the workflow worked in the interoperative setting and clearly as you can tell we we had a significant number of patients we got fairly robust function using both SSCP and CME piece and we went on further we published this last year on our on our awake craniotomy series again using multimodal monitoring DTIs sub cortical mapping navigated transcranial magnetic stimulation and so on so this was published a couple of years ago and so this this initial paper which I published in 2011 got me kind of more interested in the utility of interoperative MRI and how we could use it to monitor resections or tailor resections based on DTI images and as you can see there's a lot of papers published on sub cortical mapping based on our results this was a small group but clearly there was a correlation between interoperative what we call cortical spinal tract stimulation and the cavity and this is basically interoperative DTI and as you can see the shifts were fairly you know I don't think there's anything special about the shifts you can have a wide variation but what is important from the study was whenever we came below five millimeters from the point of stimulation to the cortical spinal tract clearly that was a that indicated that we are really close and patients clearly woke up with a deficit and so when we Tal Shahar was a visiting fellow from Tel Aviv he kind of put this paper together in terms of trying to understand how we could look at preoperative imaging and interoperative imaging to predict what we call the spatial resolution of DTI images and conclusions were fairly straightforward but there was one important conclusion which was related to primarily the tumor to CST distance in low-grade tumors and that distance was always it seemed less than a millimeter to two millimeters so clearly when when we think of resection of low-grade tumors in the interoperative setting you really don't see a lot of shift and this was supported by obviously some very nice imaging this is a patient as you can see this is from the paper we we basically the shift was less than a millimeter before and after surgery we in fact we went back and resected a little more of this tumor after after the interoperative MRI and the numbers there basically reflect the distance between the cortical spinal tract and the back of the resection cavity and so we put together the ROC graph which a lot of you are familiar with which basically had a fairly robust correlation and then when when we look at interoperative MRI and this is not new we look at shifts and shifts of the cortical spinal tract in relationship to tumors this was from that paper and we talked about inward shift outward shift and no shift and this was clearly a case where there was a significant inward shift of eight millimeters and I think this is more of a cautionary note for neurosurgeons out you know in the audience and to pay attention to to what we see interoperatively obviously we will be doing sub cortical stimulation all these patients most of these patients get continuous motor evoked potentials but at least it gives you a sense of the shifts which can occur interoperatively and in this case it was a fairly significant shift this was a recurrent glioblastoma in the prefrontal area and so this is what we do when we capture points interoperatively we the you can probably see a yellow probe which is basically my monopolar probe I use it to capture interoperative points which are then stored on the navigation screen which we can import post resection and kind of overlay them fairly precisely and that that sometimes can be a challenge when we look at the post-op imaging and so the next set of my order the next talk I'm just going to talk about some of the some of the work we've been doing using direct electrical stimulation and CST shift in the interoperative MRI so we looked at our first 53 cases and these were patients who had tumors adjacent or close to the motor gyrus all patients had preoperative DTI mapping intraoperative cortical and sub cortical direct electrical stimulation and post-operative DTI as you can see the makeup of the patients there 40 high-grade tumors for low grades we had a mix of metastases in there and off these patients 18 came back for a resection so clearly after the first scan we look at the imaging and then we felt 18 patients which is actually a third of the patients had to have a resection and this is the classification I used basically I group them into four page four groups and the the way I group them was the distance between the cortical spinal tract and the what we call the margin of the mass preoperatively so these were the four groups as you can see there was a good mix of all all types of comers here a third of the patients clearly were within that very narrow range of zero to five millimeters and obviously there's obviously in group four as you can see there's a sizable number of patients were up to 20 millimeters and so this is an example of patient who had a large cystic glioma as you can tell once the tumor is resected you can see the shift back in terms of the tissue basically this compression of the tissue which then expands back to let you know if you want to go and resect more I think this would be an opportunity to do that provided you would do careful sub cortical mapping after the resection and so when we talk about shifts this was a this these are some of the cases which I kind of learned from because you don't appreciate them once you have this technology because this was a small recurrence in the the leg area and as you can see on the the scan on the out the last scan on the right side I mentioned outward shift and the the kind of orange pink blob is basically the tumor for the resection and then the black kind of cavity is the post resection cavity so you can see post resection there was already a shift between the corticospinal tracts pre and post-op and the we have overlaid the pre and post-op corticospinal tracts in kind of gold and and blue indicating they they really don't shift they maintain their position pre and post-op but they they always have this relationship to the wall of the tumor resection and so this is another example large cingulate gyrus tumor which is a glioblastoma and as you can see the shift was minimal but clearly important because if you want to push the resection to the corticospinal tracts you really have to pay attention to that margin and that's what you know we did clearly at this at this juncture we we got a good resection this patient actually did not need to have a re-resection after the interoperative MR and I showed you this scan before again just to make the point that once we understand the shifts and doing subcortical stimulation we can always go back and do a little more of the resection if required and so this was a case where it was an inward shift and this is an inward shift is where the structures that seem come towards the cavity this was a anaplastic oligodendroglioma I ended up doing a subtotal resection the challenge here was the patient as you can see the the pre-op intra-op and inward shift was was was clearly important and and at 10 milliamp milliamps we we got a fairly robust stimulation of the lower extremities and I at this point I was kind of more nervous because I could have probably pushed it a little more but you know I was I was a little nervous because the inward shift of the corticospinal tracts clearly a subcortical mapping helped me to you know kind of understand the distances involved and so you have these situations where there's no shift and this is a glioblastoma you would expect you know some sort of infiltration some shift to the corticospinal tracts in this particular case we got a gross total resection but the point I want to make here is actually it says press probe current of 20 milliamps and these systems can sometimes fail you you know you're using fairly advanced technology for some reason we never got this our probe to work the way we wanted to and in this particular case we actually had to rely on the DTI maps to make that assumption that we got a good resection clearly this patient was not awake but he woke up well he had no deficits post op so when we look at no shift again this is a good example of glioblastoma you know preoperatively had a large kind of this was a necrotic mass again we be interoperably there was no shifts and we were comfortable resecting this tumor after doing very careful subcortical stimulation and so low-grade tumors and this is what we published obviously in the last year or so where you wouldn't expect to have any shift and and these are kind of tumors you can kind of safely assume that you will have a margin of resection like we've heard this afternoon and the in the previous talks you really want to give it a best shot by resecting as much of the margin as possible especially in these low-grade tumors and so when we think of cortical correlation between the CST and the press probe current these are some of my numbers as you can see they're especially when you look at the range between 0 to 10 millimeters there's a very tight clustering between the posterior margin of the resection cavity and the prosper current but once you get past you know 10 15 20 millimeters as you can see the clustering is the it loses that kind of clustering and I think part of the challenge then becomes where are you in this kind of three-dimensional space while you put your press probe or any other stimulation probe and so when we look at our results from the neurological standpoint in the immediate post-operative period in these 50 patients you can see we had 55% of patients had a mild neurological deficit and clearly you'll see as we go on further at three months however only 14 that is 26% had a neurological deficit but when you break that number up really the number of patients who had a new deficit was 11% so clearly this falls in line with a number of previous publications might be a little higher and clearly at one and three months the patients in group four and this is a group where you know the the margin was clearly larger in terms of distance between the corticospinal tract and the and the posterior resection margin which allowed us obviously fewer or patients had fewer neurological deficits and so when we look at our gross total resection in this group 77% had a gross total resection and among the patients who had a gross total resection obviously you know most of them were metastases we had a number of you know infiltrated gliomas but clearly this number is when I think of all the all the talks in the previous sessions you know we have to pay attention this is not a tumor you can go in and assume you can get hundred percent of the tumor out so you have to pay attention to the anatomy the function and so on and so forth and among the patients who had a re-resection clearly the intraoperative MRI helped us as you can see the resection the volume of resection increased from 84 to 95 percent and when we broke up the cases of these rear sections into what we call inward shift outward shift and no shift clearly most patients and this this was a small number I I should admit clearly there was an advantage to resecting more tumor in patients who had an outward shift and this was obviously a very modest p-value there and so when we come in conclusions I think combining information about intraoperative CST shift and DS or direct electrical stimulation in the intraoperative MRI enhances resection relationship between position of the CST which is the corticospinal tract and the post resection cavity can be altered which could affect stimulation parameters and one thing you know my understanding of CST it really maintains its same position irrespective of the mass and the volume so when I look at the gliomas and eloquent motor and sensory areas these are some of the previous publications and as you can see in the last two two columns early deficits and late deficits and that's important when you look at the numbers they are pretty high to begin with and you know the last two are unpublished which is our data from MD Anderson which we are in the process of putting together but you can see this is a fairly high number of patients who have an immediate post-op deficit and as we push the boundaries using a lot of multimodal monitoring I think in my hands anyway we are trying to push the limits of resection and so when I think of gliomas and eloquent motor and sensory areas there's significant challenge goals of surgery still remain safe maximal resection and there can be significant surgical morbidity and I can tell you when we looked at our data at MD Anderson a third of the patients really did not reach that point where they could get chemotherapy and radiation you know you know you know kind of in that four four week time point you really have to be careful when you when you give these patients any type of morbidity and and clearly as we have heard from many speakers you really have to have a good anatomical and functional knowledge at least in these even in these locations so when I just to conclude intraoperative mapping in the IMRI of eloquent motor brain provides the surgeon with real-time anatomical and functional data guides the surgeon to perform a safe maximal resection especially in tumors proximal to motor eloquent areas and mapping tools can be seamlessly integrated in the workflow thank you

interoperative MRI

mapping

cortical subcortical mapping

DTI images

surgical morbidity