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75. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie

Prof. Dr. med.

Vorsitz

Professer

Dr. med.

Prof. Dr.

Predictability of lesion locations in left-sided brain tumor patients with impaired proper name retrieval

Tumor

Prädiktivität von Läsionslokalisationen bei Patient*innen mit Benennstörung bekannter Personen und Orte und linksseitigen Hirntumoren

Proper name retrieval is often not a primary focus for neurosurgeons. However, the ability to name familiar people and places plays a vital role in social interactions. This study examines the incidence of this issue in patients with left-sided brain tumors.We assessed the incidence of impaired proper name retrieval in 55 patients with left-sided brain tumors. They underwent 107 perioperative examinations using the Anatomical Functional Aphasia Screening (AFAS). The proper name retrieval deficits were correlated with cortical and subcortical lesion locations identified by MRI/DTI tractography. A combined functional severity score (CFS) was calculated as the relative number of correctly named people and places. The CFS was compared with the overall AFAS score, which describes the general AFAS language ability (GLA).30 of 55 patients showed an impairment of proper name retrieval perioperatively (13/55 pre- and 17/55 postoperatively) with 3 patients showing an impairment in naming familiar people, 6 in naming familiar places, and 21 with a combined deficit. Primary lesion locations were temporal (disruption of UF, ILF, and MdLF; n=10; mean CFS 43.9%; mean GLA 73.7%), temporoparietooccipital (TPO) junction (IFOF, ILF, MdLF, AF; n=9; mean CFS 34.8%; mean GLA 78.6%), frontal (FAT, AF, SLF; n=5; mean CFS 64.8%; mean GLA 85%), and insular (IFOF, UF; n=7; mean CFS 26.4%; mean GLA 72%). Among the 7 patients who underwent a 3-month follow-up only 2 showed a considerable improvement of CFS (patient 1, frontal, 56% to 100%; patient 2, insular, 33.5% to 78%). No improvement was observed in the remaining 5 patients (temporal n=3; TPO n=1; insular n=1).Given its frequent occurrence, the poor recovery rate, and significant impact on daily life, proper name retrieval should be tested perioperatively in patients with relevant lesion locations. In addition, awake surgery with an intraoperative testing should be considered. (UF: uncinate fascicle; FAT: frontal aslant tract; AF: arcuate fascicle; IFOF: inf. frontooccipital fascicle; ILF/MdLF: inf./mid. longitudinal fascicles)

Abstractvortrag | Abstract talk

PD Dr.

Streamlined intraoperative Stereotactic-guided biopsy analysis: Brain tumor detection, classification and molecular subtyping with stimulated raman histology and deep learning

Prozessoptimierte intraoperative Gewebeanalyse von stereotaktischen Biopsien: Detektion, Klassifikation und molekulare Subtypisierung von Hirntumoren mit stimulierter Raman-Histologie und Deep Learning

Deep-learning-based algorithms leveraged intraoperative decision-making via stimulated Raman histology (SRH) during microsurgical resection. This study evaluates this technique for fast diagnosis during stereotactic-guided brain biopsies and defines a minimum tissue sample size, ensuring diagnostic accuracy.A prospective single-center study evaluated 121 SRH images from 84 patients with suspected intracranial lesions undergoing stereotactic-guided biopsy. Fresh, label-free tissue samples were squeezed on a slide and imaged with a portable fiber-laser Raman scattering microscope. Deep-learning-based models were tested to (1) identify tumorous/non-tumorous tissue for qualitative biopsy control, then (2) classify it into malignant glioma, diffuse low-grade glioma, metastases, lymphoma, or gliosis, and then (3) molecularly subtype the IDH- and 1p/19q-status of adult-type diffuse gliomas. Model predictions were compared to frozen section analyses and final neuropathological diagnoses.The first model identified tumorous/non-tumorous tissue with 91.5% accuracy. Tissue sample size influenced brain tumor subclassification accuracy (81.6%, κ=0.72 frozen section; 73.9%, κ=0.61 second model). SRH slide images >140 high-quality patches with a mean squeezed sample of 5.26mm2 yielded 89.5% accuracy in brain tumor subclassification comparable to conventional frozen section diagnostics and 93.9% accuracy in molecular subtyping of adult-type diffuse gliomas outperforming the limits of conventional rapid section histopathological review. Of note, the tissue sample size subject to SRH was still significantly smaller (4.1±2.5mm2) than H&E frozen sections (16.7±8.2mm2, p<0.001).AI-based image analysis is non-inferior to frozen section analysis in detecting and classifying brain tumors during small stereotactic-guided biopsies once a critically squeezed sample size is reached. It also allows for valid molecular glioma subtyping, potentially leading to faster treatment decisions in the future. Further refinement is needed for long-term clinical routine use.

Univ.-Prof. Dr. med.

Structural connectivity alterations in patients with tumor lesions in the supplementary motor area (SMA)

Veränderungen der strukturellen Konnektivität bei Patienten mit Tumoren in der supplementär-motorischen Area (SMA)

SMA tumor patients typically develop postoperatively a contralateral akinesia with or without speech deficit ("SMA syndrome"), which often regresses within the first three months. The time to recovery however varies, and has previously been related to structural integrity of transcallosal connectivity of the SMA and of the Frontal Aslant Tract (FAT). Whether SMA tumor patients differ in structural connectivity (SC) already prior to surgical intervention is however unclear. We investigated diffusion-MRI based SC in SMA tumor patients preoperatively compared to healthy controls. 13 SMA tumor patients (10 gliomas/2 metastases/1 meningioma; 5 right-hemispheric; mean age 49±21 yrs), and 13 matched healthy controls (49±16 yrs) underwent diffusion-MRI preoperatively. Applying deterministic diffusion tractography, SC of the FAT, and of transcallosal SMA connectivity to the contralateral SMA (SMA-SMA), and to the contralateral primary motor cortex (SMA-M1) was analyzed. Normalized parameters evaluated for each tract were tract volume, number of fibers, tract length, as well as mean fractional anisotropy (FA), and mean-, radial-, and axial-diffusivity (MD, RD, AD), which were compared between patients and controls.For FAT connectivity, patients showed a trend towards smaller tract volumes, with MD (p<.012) and AD (p<.010) being ipsilesionally increased only in patients. Transcallosal SMA-SMA connectivity did not significantly differ between groups, although the mean number of fibers appeared to be increased in some of the patients (Meanpatients=0.81+/-0.47; Meancontrols=0.56+/-0.34), which however did not reach significance due to the high variance. For SMA-M1 connectivity, tract volumes were reduced (p<.005), and fiber length of contralesional compared to ipsilesional SMA-M1 connections (p<.026), as well as AD (p<.019) were increased in patients.Patients showed tumor-associated signs of ipsilesional and transcallosal microstructural white matter disintegration, but with a high variance in homologue transcallosal SMA connectivity. Variability in transcallosal connectivity might relate to differing abilities for bihemispheric or contralateral information processing. Longitudinal studies should evaluate, whether tumor-associated alterations of transcallosal connectivity impact on the postoperative functional outcome in SMA tumor patients

Prof

Preservation of language during awake craniotomy for infiltrating brain tumors – A new diagnostic tool improves functional resolution

Optimierte Sprachtestung bei Wach-Operationen von infiltrierenden Hirntumoren

The preservation of language functions despite the goal of supramaximal resection for infiltrating brain tumors, necessitates the intraoperative identification of language-associated areas. The current standard of language assessment addresses word-level articulation (e.g., counting or word repetition), word retrieval (picture naming-PN) or identification and semantic-relatedness (pyramid-palm tree test-PPTP). These tests are all at the word level. As such, they probe language functions very partially. We humans communicate via sentence and stories, not just word. To move to this level, we adopted a linguistic approach, and constructed a test battery comprising of a relatively rich variety of sentence types whose comprehension we tested. We then evaluated the feasibility and sensitivity of newly developed linguistic tests in awake surgery for infiltrating brain tumor. In this prospective study, patients planned for awake craniotomy performed (peri- and intra-operatively) an app-based linguistic language test (sentence comprehension of different syntactic and semantic types) in addition to the standard test (counting, PN, PPTP). We applied these tests peri- and intra-operatively. This enabled a comparison between patients" performance on the new linguistic tests and the standard tests. Thus far, we have tested 140 patients peri-operatively, of which about 25 were also tested intra-operatively. While the analysis is still in progress, we can report three important results: a. the test is highly feasible: most patients can carry out the test at all stages. b. while patients" performance standard word-level tests tends to be at ceiling (at least pre-operatively), thereby failing to differentiate between different functional deficits, the new sentence-level tests rarely record performance at ceiling (although healthy controls are always at ceiling). c. the new tests evince much higher individual variability.Our preliminary results demonstrate (i) the feasibility of the linguistic test application at all stages; (ii) the resolution of the new test is higher: it uncovers language impairments not revealed by standard testing. This suggests that the current standard of care can be improved with the new tool.

PD. Dr.

Voxel-based analysis of the hemorrhage risk after stereotactic and robotic brain biopsies

Voxel-basierte Analyse des Blutungsrisikos nach stereotaktischen und robotergestützten Hirnbiopsien

Glioma therapy is increasingly guided by molecular characteristics of the tumor, emphasizing the evolving significance of brain biopsies. At the same time, there is an increasing application of robotic technology in acquiring tumor samples reducing invasiveness and surgical time. Nevertheless, hemorrhages remain a major concern. This study aimed to understand risk factors for hemorrhage and differences between surgical techniques from a large cohort undergoing stereotactic and robotic needle biopsies.We analyzed 345 frame-based (FRAME, n=177) and robotic (ROBOT, n=168) trajectories in 327 patients undergoing stereotactic biopsy in a 10 years period. Patients" preoperative MR and postoperative CT imaging were registered and normalized to the standard MNI space enabling standardized volumetry of postoperative hemorrhage and inter-subject comparison of bleeding location. Additionally, we analyzed skin-to-skin time (STS), the surgical approach (burr hole and twist drill), diagnostic yield (DY) and permanent morbidity (PM) in both groups.After the integration of robotic technology, there was a significant shift to twist drill approaches (70.8% vs 14.7%) resulting in a significant STS reduction. Both techniques had a excellent DY (98.6% and 99.4%). Asymptomatic hemorrhages were detected on postoperative CT scans in 12.5%, however only 2.8% showed transient neurological deterioration. Permanent morbidity was detected in 1.8%. There were no differences in hemorrhage risk comparing stereotactic and robotic biopsies. Voxel-based analysis demonstrated a higher risk for deep-seated lesions within the basal ganglia and the thalamus. Hemorrhages occurred predominantly at the target (especially in high-grade glioma) and the cortical entry area. There were no significant differences in hemorrhages comparing stereotactic and robotic biopsies or different surgical approaches (burr hole and twist drill).Both stereotactic and robotic brain biopsies are safe. While asymptomatic hemorrhages are quite common after brain biopsies, neurological deterioration is rare. Deep-seated location and high-grade gliomas are independent risk factors. The introduction of robotics modified the surgical approach decreasing duration and the invasiveness without affecting the diagnostic yield or the complication rate.

Entwicklung und Validierung eines deep learning basierten Modells zur präoperativen Unterscheidung von Glioblastomen und zerebralen Lymphomen vor stereotaktischer Biopsie

Development and validation of a deep learning-based model for the preoperative differentiation of glioblastomas and cerebral lymphomas prior to stereotactic biopsy

Session 22
Tumor – Verschiedenes 2

Appointment

Vorsitz

Topic

Programme

Session 22Tumor – Verschiedenes 2

Appointment

Vorsitz

Topic

Programme

Session 22
Tumor – Verschiedenes 2