Intraoperative Magnetic Resonance Imaging Research Articles

P.111 5-ALA guided surgical resection of newly diagnosed high grade gliomas at Health Sciences North (HSN) in Sudbury, Ontario

Background: Since its approval by Health Canada in 2020, several neurosurgical centres across Canada have used 5-ALA, an oral drug that assists with surgical resection of malignant gliomas by causing tumour cells to fluoresce under the microscope. The study’s objective is to prospectively evaluate the extent of resection (EOR) and clinical outcomes in 5-ALA-guided surgery at HSN compared to historical controls. Methods: A retrospective analysis was performed of patients with malignant gliomas having undergone surgery at HSN from 2011 to December 2020, assessing the EOR (contrast-enhanced tumour on post-operative CT/MRI), progression-free survival (PFS), overall survival (OS). Results: 235 patients underwent surgery for malignant glioma including 51 newly-diagnosed patients felt to be surgically resectable and with post-operative imaging. 25/51 (49%) had no residual tumour. The median PFS and OS were 7.1 and 11.5 months respectively. To date, 3 patients have successfully undergone 5-ALA-guided surgery with complete resection of contrast-enhancing tumour and no new focal neurological deficit post-operatively. Conclusions: We continue to recruit and follow prospectively patients having undergone 5-ALA-guided resection of malignant gliomas at HSN. Patients living in Northern Ontario may derive significant benefits from the use of 5-ALA-guided surgery, particularly since other technologies, such as intraoperative MRI and ultrasound, are costly and not available.

Comfortable Nursing in the Intraoperative MRI Evaluation Combined with Microsurgery in the Treatment of Functional Area Glioma

This study was aimed to investigate the application value of magnetic resonance imaging (MRI) scanning examination in the preoperative treatment of functional glioma and to analyze the application effect of nursing intervention in the operating room in the treatment of fiber surgery. In this study, 80 patients with functional glioma were included as research objects and randomly rolled into the control group (routine nursing) and the experimental group (comfort nursing intervention in the operating room), with 40 cases in each group. All patients underwent craniocerebral MRI plain scan plus enhanced scan before surgery. The levels of the heart rate, systolic blood pressure, diastolic blood pressure, interleukin-6 (IL-6), cortisol, and anxiety before and after the intervention in the two groups were compared when patients entered the operating room (T1), when anesthesia took effect (T2), at the end of surgery (T3), when patients regained consciousness after surgery (T4), and 1 day after surgery (T5). MRI showed that the main glioma sites were located in the basal ganglia region (26.25%), followed by the central region (20.00%) and the Broca region (17.5%). The levels of IL-6 at T2, T3, and T4 in the control group were 186.45 ± 64.55 ng/L, 287.68 ± 34.59 ng/L, and 488.69 ± 81.14 ng/L, respectively, which were inferior to those at T2 (167.44 ± 15.59 ng/L), T3 (186.25 ± 52.64 ng/L), and T4 (356.57 ± 48.22 ng/L) in the test group. The SAS score of the test group after intervention (45.38 ± 2.02) was lower than that of the control group (51.03 ± 3.65) ( P < 0.05 ). The levels of cortisol in the test group (T2 (8.89 1.23 ng/L), T3 (9.23 1.25 ng/L), and T4 (11.78 1.27 ng/L) were lower than those in the control group (T2 (11.58 ± 2.48 ng/L), T3 (12.06 ± 2.82 ng/L), and T4 (13.04 ± 11.78)). In short, preoperative MRI scanning was beneficial to detect the location of glioma in functional area. Comfort nursing in the operating room can effectively relieve the anxiety and depression of glioma patients and improve the adverse psychological conditions of the patients.

Combined use of intraoperative MRI and awake tailored microsurgical resection to respect functional neural networks: preliminary experience.

The combined use of intraoperative MRI and awake surgery is a tailored microsurgical resection to respect functional neural networks (mainly the language and motor ones). Intraoperative MRI has been classically considered to increase the extent of resection for gliomas, thereby reducing neurological deficits. Herein, we evaluated the combined technique of awake microsurgical resection and intraoperative MRI for primary brain tumours (gliomas, metastasis) and epilepsy (cortical dysplasia, non-lesional, cavernomas). Eighteen patients were treated with the commonly used "asleep awake asleep" (AAA) approach at Lille University Hospital, France, from November 2016 until May 2020. The exact anatomical location was insular with various extensions, frontal, temporal or fronto-temporal in 8 (44.4%), parietal in 3 (16.7%), fronto-opercular in 4 (22.2%), Rolandic in two (11.1%), and the supplementary motor area (SMA) in one (5.6%). The patients had a mean age of 38.4 years (median 37.1, range 20.8-66.9). The mean surgical duration was 4.1 hours (median 4.2, range 2.6-6.4) with a mean duration of intraoperative MRI of 28.8 minutes (median 25, range 13-55). Overall, 61% (11/18) of patients underwent further resection, while 39% had no additional resection after intraoperative MRI. The mean preoperative and postoperative tumour volumes of the primary brain tumours were 34.7 cc (median 10.7, range 0.534-130.25) and 3.5 cc (median 0.5, range 0-17.4), respectively. Moreover, the proportion of the initially resected tumour volume at the time of intraoperative MRI (expressed as 100% from preoperative volume) and the final resected tumour volume were statistically significant (p= 0.01, Mann-Whitney test). The tumour remnants were commonly found posterior (5/9) or anterior (2/9) insular and in proximity with the motor strip (1/9) or language areas (e.g. Broca, 1/9). Further resection was not required in seven patients because there were no remnants (3/7), cortical stimulation approaching eloquent areas (3/7) and non-lesional epilepsy (1/7). The mean overall follow-up period was 15.8 months (median 12, range 3-36). The intraoperative MRI and awake microsurgical resection approach is feasible with extensive planning and multidisciplinary collaboration, as these methods are complementary and synergic rather than competitive to improve patient oncological outcomes and quality of life.

Pituitary Surgery in Germany - Findings from the European Pituitary Adenoma Surgery Survey.

Surgery is, next to medical and radiation therapy, the mainstay therapy for pituitary adenomas. While scientific consensus regarding the key aspects of pituitary surgery exists among neurosurgeons, procedures are not standardized and might vary significantly between hospitals and surgeons. To provide an overview of how neurosurgical departments in Germany manage pituitary surgery. Responses from the European Pituitary Adenoma Surgery Survey were analyzed. The survey contained 60 questions regarding demographics, training, surgical and endocrinological aspects, and patient management. Sixty neurosurgical centers from Germany responded to the survey. Among the centers, 35.3% (n=18) exclusively use the microscopic and 31.1% (n=14) the endoscopic technique; all other centers (n=28) use both approaches. Of responding centers, 20% (n=12) perform less than 10 transsphenoidal pituitary surgeries per year, and 1.7% (n=1), more than 100 operations. The number of transcranial pituitary operations is significantly smaller, with 53.3% of centers performing only 0-2 per year, 35% performing 3-5, and only one center (1.7%) performing more than 15 transcranial operations per year. In 8 centers (13.3%), surgeries are always performed together with an ENT surgeon; in 29 centers (48.4%) ENT surgeons are never involved. In most centers (n=54, 90%) intraoperative MRI is not available. Image guidance (with preoperative CT and/or MRI data) is used by 91.7% of respondents (n=55). Forty-two centers (72.4%) routinely prescribe hydrocortisone after pituitary surgery, and 75% (n=45) have pituitary board meetings with endocrinologists, radiologists, and radiosurgeons. Fifty-two (86.7%) respondents perform the first follow-up scan by MRI 3-4 months after surgery. The data showed differences as well as similarities between centers and could help to discuss the standardization of methods and the formation of networks and certification to improve patient care.

Advances in surgical approaches for refractory pituitary adenomas.

Refractory pituitary adenomas are difficult to control tumors that progress through optimal surgical, medical, and radiation management. Repeat surgery is a valuable tool to reduce tumor volume for more effective radiation and/or medical therapy, and to decompress critical neurovascular structures. Advances in surgical techniques and technologies, including minimally invasive cranial approaches, intraoperative MRI suites, and cranial nerve monitoring, have improved surgical outcomes and expanded indications. Today, repeat transsphenoidal surgery has similar complications rates to upfront surgery in historical cohorts. The decision to operate on refractory adenomas should be made with multidisciplinary teams, balancing the benefit of tumor reduction with the potential for complications, including cranial nerve injury, carotid injury, and cerebrospinal fluid leak.

Clinical utility of intraoperative Arterial Spin Labeling for resection control in brain tumor surgery at 3 T.

Resection control in brain tumor surgery can be achieved in real time with intraoperative MRI (iMRI). Arterial spin labeling (ASL), a technique that measures cerebral blood flow (CBF) noninvasively without the use of intravenous contrast agents, can be performed intraoperatively providing morpho-physiological information. This study aimed to evaluate the feasibility, image quality and potential to depict residual tumor of a pseudo-continuous-ASL (PCASL) sequence at 3T. 17 patients with brain tumors, primary (16) or metastatic (1), undergoing resection surgery with iMRI-monitoring were prospectively recruited (9 men, age:56±16.6 years). A PCASL sequence with long labeling duration (3000ms) and postlabeling delay (2000ms) was added to the conventional protocol that consisted of pre- and post-contrast 3D-T1-weighted (T1w) images, optional 3D-FLAIR, and diffusion. Three observers independently assessed image quality (4-point scale) of PCASL-derived CBF maps. In those with diagnostic quality (scores 2-4) they evaluated the presence of residual tumor using the conventional sequences first, and the CBF maps afterwards (3-point scale). Inter-observer agreement for image quality and the presence of residual tumor was assessed using Fleiss-kappa statistics. Intraoperative CBF-ratio of the surgical margins (i.e., perilesional CBF values normalized to contralateral gray matter CBF) was compared to preoperative CBF-ratio within the tumor (Wilcoxon's test). Diagnostic ASL image quality was observed in 94.1% of patients (inter-observer Fleiss-κ=0.76). PCASL showed additional foci suspicious of high-grade residual component in three patients, and a hyperperfused area extending outside the enhancing component in one patient. Interobserver agreement was almost perfect in the evaluation of residual tumor with the conventional sequences (Fleiss-κ=0.92) and substantial for PCASL (Fleiss-κ=0.80). No significant differences were found between pre and intraoperative CBF-ratios (p=0.578) in patients with residual tumor (n=7). iMRI-PCASL perfusion is feasible at 3T and is useful for the intraoperative assessment of residual tumor, providing in some cases additional information to the conventional sequences.

Advanced intraoperative MRI in pediatric brain tumor surgery.

Introduction: In the pediatric brain tumor surgery setting, intraoperative MRI (ioMRI) provides "real-time" imaging, allowing for evaluation of the extent of resection and detection of complications. The use of advanced MRI sequences could potentially provide additional physiological information that may aid in the preservation of healthy brain regions. This review aims to determine the added value of advanced imaging in ioMRI for pediatric brain tumor surgery compared to conventional imaging. Methods: Our systematic literature search identified relevant articles on PubMed using keywords associated with pediatrics, ioMRI, and brain tumors. The literature search was extended using the snowball technique to gather more information on advanced MRI techniques, their technical background, their use in adult ioMRI, and their use in routine pediatric brain tumor care. Results: The available literature was sparse and demonstrated that advanced sequences were used to reconstruct fibers to prevent damage to important structures, provide information on relative cerebral blood flow or abnormal metabolites, or to indicate the onset of hemorrhage or ischemic infarcts. The explorative literature search revealed developments within each advanced MRI field, such as multi-shell diffusion MRI, arterial spin labeling, and amide-proton transfer-weighted imaging, that have been studied in adult ioMRI but have not yet been applied in pediatrics. These techniques could have the potential to provide more accurate fiber tractography, information on intraoperative cerebral perfusion, and to match gadolinium-based T1w images without using a contrast agent. Conclusion: The potential added value of advanced MRI in the intraoperative setting for pediatric brain tumors is to prevent damage to important structures, to provide additional physiological or metabolic information, or to indicate the onset of postoperative changes. Current developments within various advanced ioMRI sequences are promising with regard to providing in-depth tissue information.

How to combine the use of intraoperative magnetic resonance imaging (MRI) and awake craniotomy for microsurgical resection of hemorrhagic cavernous malformation in eloquent area: a case report

BackgroundCavernous malformations are clusters of abnormal and hyalinized capillaries without interfering brain tissue. Here, we present a cavernous malformation operated under awake conditions, due to location, in an eloquent area and using intraoperative magnetic resonance imaging due to patient’s movement upon the awake phase.Case presentationWe present the pre-, per-, and postoperative course of an inferior parietal cavernous malformation, located in eloquent area, in a 27-year-old right-handed Caucasian male, presenting with intralesional hemorrhage and epilepsy. Preoperative diffusion tensor imaging has shown the cavernous malformation at the interface between the arcuate fasciculus and the inferior fronto-occipital fasciculus. We describe the microsurgical approach, combining preoperative diffusion tensor imaging, neuronavigation, awake microsurgical resection, and intraoperative magnetic resonance imaging.ConclusionComplete microsurgical en bloc resection has been performed and is feasible even in eloquent locations. Intraoperative magnetic resonance imaging was considered an important adjunct, particularly used in this case as the patient moved during the “awake" phase of the surgery and thus neuronavigation was not accurate anymore. Postoperative course was marked by a unique, generalized seizure without any adverse event. Immediate and 3 months postoperative magnetic resonance imaging confirmed the absence of any residue. Pre- and postoperative neuropsychological exams were unremarkable.

Endoscopic Endonasal Transsphenoidal Surgery for Resection of Craniopharyngioma in Pediatric Population: A Comprehensive Review of the Literature

AbstractCraniopharyngioma is a rare epithelial brain tumor which arises from the embryological remnants of Rathke's pouch—a remnant of the primitive pharynx. The proximity of this tumor to the pituitary stalk, hypothalamus, third ventricle, optic chiasm, and optic nerves, as well as the major intracranial vessels bridging this area, makes safe surgical resection challenging. Given the recent advancement in endoscopic surgical techniques and the intraoperative assistance of neuronavigation and intraoperative magnetic resonance imaging, endoscopic endonasal transsphenoidal surgery (EETS) can be an alternative to the open transcranial approaches in the management of children with craniopharyngioma who fulfill the appropriate selection criteria. The comparison between the EETS and the open transcranial approach regarding the clinical and surgical outcomes could be subject to an inherent selection bias. In this article, we reviewed the body of the literature on the role of EETS in the management of pediatric craniopharyngioma and the proper selection criteria of children with craniopharyngioma, who might be suitable candidates for tumor resection via this minimally invasive endoscopic approach. We also looked at the preoperative assessment, surgical techniques, surgical and clinical outcomes, and the possible complications of endoscopic endonasal transsphenoidal surgery.

SlicerCBM: automatic framework for biomechanical analysis of the brain

PurposeBrain shift that occurs during neurosurgery disturbs the brain’s anatomy. Prediction of the brain shift is essential for accurate localisation of the surgical target. Biomechanical models have been envisaged as a possible tool for such predictions. In this study, we created a framework to automate the workflow for predicting intra-operative brain deformations.MethodsWe created our framework by uniquely combining our meshless total Lagrangian explicit dynamics (MTLED) algorithm for computing soft tissue deformations, open-source software libraries and built-in functions within 3D Slicer, an open-source software package widely used for medical research. Our framework generates the biomechanical brain model from the pre-operative MRI, computes brain deformation using MTLED and outputs results in the form of predicted warped intra-operative MRI.ResultsOur framework is used to solve three different neurosurgical brain shift scenarios: craniotomy, tumour resection and electrode placement. We evaluated our framework using nine patients. The average time to construct a patient-specific brain biomechanical model was 3 min, and that to compute deformations ranged from 13 to 23 min. We performed a qualitative evaluation by comparing our predicted intra-operative MRI with the actual intra-operative MRI. For quantitative evaluation, we computed Hausdorff distances between predicted and actual intra-operative ventricle surfaces. For patients with craniotomy and tumour resection, approximately 95% of the nodes on the ventricle surfaces are within two times the original in-plane resolution of the actual surface determined from the intra-operative MRI.ConclusionOur framework provides a broader application of existing solution methods not only in research but also in clinics. We successfully demonstrated the application of our framework by predicting intra-operative deformations in nine patients undergoing neurosurgical procedures.

Intraoperative MRI-derived volumetric ablation margins and initial correlation with local outcome after MRI-guided cryoablation of renal tumors

PurposeTo assess volumetric ablation margins derived from intraoperative pre- and post-ablation MRI after magnetic resonance imaging (MRI)-guided percutaneous cryoablation of renal tumors and explore its correlation with local treatment success.MethodsRetrospective analysis was performed on 30 patients (mean age 69y) who underwent percutaneous MRI-guided cryoablation between May 2014 and May 2020 for 32 renal tumors (size: 1.6–5.1 cm). Tumor and ice-ball volumes were segmented on intraprocedural pre- and post-ablation MR images using Software Assistant for Interventional Radiology (SAFIR) software. After MRI-MRI co-registration, the software automatically quantified the minimal treatment margin (MTM),defined as the smallest 3D distance between the tumor and ice-ball surface. Local tumor progression (LTP) after cryoablation was assessed on follow-up imaging.ResultsMedian follow-up was 16 months (range: 1–58). Local control after cryoablation was achieved in 26 cases (81%) while LTP occurred in 6 (19%). The intended MTM of ≥5 mm was achieved in 3/32 (9%) cases. Median MTM was significantly smaller for cases with (− 7 mm; IQR:-10 to − 5) vs. without LTP (3 mm; IQR:2 to 4) (P < .001). All cases of LTP had a negative MTM. All negative treatment margins occurred in tumors > 3 cm.ConclusionsDetermination of volumetric ablation margins from intraoperative MRI was feasible and may be useful in predicting local outcome after MRI-guided renal cryoablation. In our preliminary data, an intraoperative MRI-derived minimal margin extending at least 1 mm beyond the MRI-visible tumor led to local control and this was more difficult to achieve in tumors > 3 cm. Ultimately, online margin analysis may be a valuable tool to intraoperatively assess therapy success, but larger prospective studies are needed to establish a reliable threshold for clinical use.

Intraoperative MRI use in transsphenoidal surgery for pituitary tumors: Trends and healthcare utilization

BackgroundIntraoperative magnetic resonance imaging (iMRI) use in transsphenoidal approach (TSA) for pituitary tumors (PTs) has been reported to improve the extent of resection (EOR). The aim of this study is to report the trends and the impact of iMRI on healthcare utilization in patients who underwent TSA for PTs. Materials and methodsMarketScan database were queried using the ICD-9/10 and CPT-4, from 2004 to 2020. We included patients ≥ 18 years of age PTs with > 1 year follow-up. Outcomes were length of stay (LOS), discharge disposition, hospital/emergency room (ER) re-admissions, outpatient services, medication refills and corresponding payments. ResultsA cohort of 10,192 patients were identified from the database, of these 141 patients (1.4%) had iMRI used during the procedure. Use of iMRI for PTs remained stable (2004–2007: 0.85%; 2008–2011: 1.6%; 2012–2015:1.4% and 2016–2019: 1.46%). No differences in LOS (median 3 days each), discharge to home (93% vs. 94%), complication rates (7% vs. 13%) and payments ($34604 vs. $33050) at index hospitalization were noted. Post-discharge payments were not significantly different without and with iMRI use at 6-months ($8315 vs. $ 7577, p = 0.7) and 1-year ($13,654 vs. $ 14,054, p = 0.70), following the index procedure. ConclusioniMRI use during TSA for PTs remained stable with no impact on LOS, complications, discharge disposition and index payments. Also, there was no difference in combined index payments at 6-months, and 1-year after the index procedure in patients with and without iMRI use for PTs.

Pinless Electromagnetic Neuronavigation During Awake Craniotomies: Technical Pearls, Pitfalls, and Nuances

Awake craniotomies are often performed with rigid pin fixation to support optical neuronavigation. Newer electromagnetic (EM) neuronavigation technology now enables unpinned cranial neurosurgery while maintaining robust intraoperative image guidance. Here, we share technical nuances, operative pearls, and lessons learned from our institutional experience using Curve EM neuronavigation during awake, unpinned craniotomies. We describe our process for patient positioning, instrumentation setup, system registration, intraoperative navigation, and surgical adjunct use (e.g., intraoperative neuromonitoring and intraoperative magnetic resonance imaging) in detail. At each step, we provide pearls for success and tips for pitfall avoidance based on our experience. Ten patients underwent awake pinless intra-axial tumor resection using Curve EM neuronavigation from May 2021 to August 2022 with a single surgeon. Postoperative transient neurological deficits were seen in 8 of 10 cases (80.0%), as all resections were taken to functional margins. Of the 9 patients with a 3-month follow-up visit at the time of publication, all 9 (100%) had improved or stable preoperative symptoms. No surgical complications, clinically appreciable inaccuracies, intraoperative losses of registration, unexpected postoperative magnetic resonance imaging findings, or errors related to the use of EM neuronavigation occurred. The technical pearls outlined here willhelp interested neurosurgeons integrate EM neuronavigation into awake craniotomies. In our experience, using unpinned neuronavigation during awake cases provides many advantages to the patient, surgeon, and entire operative team. It has thus become the standard practice at our institution.

Pediatric neuroanesthesia experiences: A single center retrospective cohort study

Background/Aim: Pediatric neuroanesthesia is a special field that requires significant experience and infrastructure because of anatomical, neurological, and pharmacological differences in the pediatric patient population. Although technological improvements provide more effective and safer neuroanesthesiological management, the principles of neuroanesthesia, neurocognitive development, and the effects of anesthetic agents on central nervous system development are well-known. The majority of pediatric neuroanesthesia articles in the literature are reviews; however, retrospective/prospective case series and controlled research are limited. In this retrospective cohort study, we aimed to contribute to the existing literature by reviewing and analyzing our single-center 10-year experiences and results addressing pediatric neuroanesthesia management. Methods: After ethical committee approval, anesthetic and surgical reports from 1165 pediatric neurosurgical cases over ten years were collected. Demographic data, intra-operative vascular management, anesthesia techniques, airway management, patient positions, analgesia methods, and complications were evaluated in this retrospective cohort study. The available surgical intervention, patient positions, intra-operative neuromonitorization (IONM), and intra-operative magnetic resonance imaging (IOMR) records were also analyzed. Results: Six-hundred forty-six (55.4%) girls and 519 (44.5%) boys were included in the study. The median age was 60 (0–216) months. Cranial interventions were performed in 842 (72.3%) patients, and spinal interventions were performed in 323 (27.7%) patients. Patients’ American Society of Anesthesiologists (ASA) physical scales grouped as I, II, III, and IV were 718 (61.6%), 360 (30.9%), 82 (7%), and 5 (0.4%), respectively. Sevoflurane (40.3%), propofol (37.2%), and sodium thiopental (2.5%) were used for anesthetic induction. Neuromuscular block was performed with rocuronium (56.7%) and atracurium (14.4%). Neuromuscular blocking agents were not used in 337 patients (28.9%). A blood transfusion was required in 120 patients (10.3%), and 40% of these patients underwent surgery for craniosynostosis. Two-hundred twenty-two (19.1%) were monitored with IONM, and IOMR was carried out in 124 (10.6%) of the cases. The anesthesia-related complication rate was 5.15% (60 patients). Conclusion: Although pediatric neurosurgical interventions involve high risks, they are becoming increasingly common in our daily practice. Neuroanesthesiologists should know the procedures, techniques, and advances for safe and effective management of pediatric neurosurgical cases. We think that these data may be helpful as a guide for the anesthetic management of pediatric neurosurgical cases.

Right gyrus cinguli low-grade astrocytoma recurrence removed through a contralateral transfalcine approach with a 4K-3D exoscope

BackgroundBrain tumor surgery has been using operative microscope for years. Recently, thanks to developments in surgical technology with procedures performed on head-up displays, exoscopes have been introduced as an alternative to microscopic vision.Case presentationWe present a case of a 46-year-old patient with a low-grade glioma recurrence of the right gyrus cinguli removed with a contralateral transfalcine approach using an exoscope (ORBEYE 4K-three-dimensional (3D) exoscope, Sony Olympus Medical Solutions Inc., Tokyo, Japan).The operating room setup for this approach is illustrated.During the procedure, the surgeon was seated with head and back in an upright position, while the camera was aligned with the surgical corridor.The exoscope provided detailed, high-quality 4K-3D images of the anatomical structures and optimal depth perception, making surgery accurate and precise.At the end of the resection, an intraoperative MRI scan showed complete removal of the lesion. The patient was discharged on postoperative day 4 with an excellent performance on neuropsychological examination.ConclusionsIn this clinical case the contralateral approach was favorable because the glioma was located close to the midline and because it offered a straight path to the tumor, minimizing retraction on the brain. The exoscope provided the surgeon with important advantages in terms of anatomical visualization and ergonomics during the entire procedure.

Evaluation of the Efficiency of Neuronavigation in Patients with Glioblastoma

Objective: To investigate the effect of neuronavigation use on mortality in patients with glioblastoma. Methods: For each of the 26 patients that underwent neuronavigation-assisted supratotal resection for glioblastoma between 2018 and 2020, one patient that underwent supratotal resection without navigation was selected. Results: Radiographic radicality was observed in 35% of the cases in the neuronavigation-assisted surgery group and 29% of those in the conventional surgery group. Absolute and relative residual tumor volumes were significantly lower in the neuronavigation-assisted surgery group. Radical tumor resection was associated with a very significant increase in survival. There was no significant difference in the survival rates between the patients that underwent surgery with and without neuronavigation. This was attributed to the small number of participants and supratotal resection being performed in all statistically determined patients The low median survival period of glioblastoma may have also contributed to this finding. Conclusions: Surgery plays an important role in the treatment of glioblastoma. A combination of techniques including intraoperative magnetic resonance imaging, neuronavigation, ultrasound, and fluorescence guidance allows for safe and maximum surgical resection, leading to better outcomes in terms of survival and postoperative functional recovery. However, despite maximal surgical resection and adjuvant chemotherapy-radiotherapy, most cases develop tumor recurrence within 10 months, which is considered to be due to established cancer stem cells. Therefore, there is an urgent need to develop more effective treatment strategies for glioblastoma.

Side-Firing Intraoperative Ultrasonograhy for Resection of Giant Pituitary Adenomas

Suprasellar extension, cavernous sinus invasion, and involvement of intracranial vascular structures and cranial nerves are among the challenges faced by surgeons operating on giant pituitary macroadenomas. Intraoperative tissue shifts may render neuronavigation techniques inaccurate. Intraoperative magnetic resonance imaging can solve this problem, but it may be costly and time consuming. However, intraoperative ultrasonography (IOUS) allows for quick, real-time feedback and may be particularly useful when facing giant invasive adenomas. Here, we present the first study examining technique for IOUS-guided resection specifically focusing on giant pituitary adenomas. To describe the use of a side-firing ultrasound probe in the resection of giant pituitary macroadenomas. We describe an operative technique using a side-firing ultrasound probe (Fujifilm/Hitachi) to identify the diaphragma sellae, confirm optic chiasm decompression, identify vascular structures related to tumor invasion, and maximize extent of resection in giant pituitary macroadenomas. Side-firing IOUS allows for identification of the diaphragma sellae to help prevent intraoperative cerebrospinal fluid leak and maximize extent of resection. Side-firing IOUS also aids in confirmation of decompression of the optic chiasm via identification of a patent chiasmatic cistern. Furthermore, direct identification of the cavernous and supraclinoid internal carotid arteries and arterial branches is achieved when resecting tumors with significant parasellar and suprasellar extension. We describe an operative technique in which side-firing IOUS may assist in maximizing extent of resection and protecting vital structures during surgery for giant pituitary adenomas. Use of this technology may be particularly valuable in settings in which intraoperative magnetic resonance imaging is not available.

Stereotactic and Functional Neurosurgery Convection-Enhanced Delivery of Autologous Cerebrospinal Fluid Enhances Basal Ganglia Visualization during MRI-Guided Deep Brain Stimulation Surgery

Introduction: The aim of this study was to determine the safety and feasibility of convection-enhanced delivery of autologous cerebrospinal fluid (CSF) for enhancing intraoperative magnetic resonance imaging (MRI) of the basal ganglia during stereotactic neurosurgery. Methods: This pilot study was conducted in 4 patients with Parkinson’s disease (PD) who underwent MRI-guided deep brain stimulation of the globus pallidus internus (GPi). CSF was obtained via lumbar puncture after general anesthesia and prior to incision. A frameless stereotaxy system was installed, and an infusion catheter was inserted to the GPi using intraoperative MRI. Infusion of autologous CSF was performed at a convective rate of 5 µL/min with a maximum volume of infusion (Vi) of 500 mL. T2-weighted MRI scans were obtained every 15 min up to a maximum of 105 min in order to calculate the volume of distribution (Vd). Safety was assessed with adverse event monitoring, and clinical outcomes were measured with changes in unmedicated UPDRS part III and PDQ-39 scores from baseline to 6 months postoperatively. Results: All four infusions were safe and without adverse events. The mean unmedicated UPDRS part III and PDQ-39 scores improved by 24% and 26%, respectively. The Vd:Vi ratio ranged from 2.2 to 2.8 and peaked 45 min from the onset of infusion, which is when the borders of the GPi could generally be visualized based on T2-weighted MRI. Two patients underwent refinement of the stereotactic targeting based on infusion-enhanced images. Conclusions: The convective administration of autologous CSF to deep brain structures appears safe and feasible for enhancing intraoperative MRI during stereotactic procedures. Infusion-enhanced imaging with target-specific infusates could be developed to visualize neurochemical circuits or cellular regions that currently are not seen with anatomic/structural MRI.

It is not the time to abandon intraoperative frozen section in endometrioid adenocarcinoma: A large-scale, multi-center, and retrospective study.

Stage IB (deep myometrial invasion) high-grade endometrioid adenocarcinoma (EA), regardless of LVSI status, is classified into high-intermediate risk groups, requiring surgical lymph node staging. Intraoperative frozen section (IFS) is commonly used, but its adequacy and reliability vary between reports. Hence, we determined the utility of IFS in identification of high-risk factors, including deep myometrial invasion and high-grade. We retrospectively analyzed 9,985 cases operated with hysterectomy and diagnosed with FIGO stage I/II EA in postoperative paraffin section (PS) results at 30 Chinese hospitals from 2000 to 2019. We determined diagnostic performance of IFS and investigated whether the addition of IFS to preoperative biopsy and imaging could improve identification of high-risk factors. IFS and postoperative PS presented the highest concordance in assessing deep myometrial invasion (Kappa: 0.834), followed by intraoperative gross examination (IGE Kappa: 0.643), MRI (Kappa: 0.395), and CT (Kappa: 0.207). IFS and postoperative PS presented the highest concordance for high-grade EA (Kappa: 0.585) compared to diagnostic curettage (D&C 0.226) and hysteroscope (Hys 0.180). Sensitivity and specificity for detecting deep myometrial invasion were 86.21 and 97.20% for IFS versus 51.72 and 88.81% for MRI, 68.97 and 94.41% for IGE. These figures for detecting high-grade EA were 58.21 and 96.50% for IFS versus 16.42 and 98.83% for D&C, 13.43 and 98.64% for Hys. Parallel strategies, including MRI-IFS (Kappa: 0.626), D&C-IFS (Kappa: 0.595), and Hys-IFS (Kappa: 0.578) improved the diagnostic efficiencies of individual preoperative examinations. Based on the high sensitivity of IFS, parallel strategies improved the sensitivities of preoperative examinations to 89.66% (MRI), 64.18% (D&C), 62.69% (Hys), respectively, and these differences were statistically significant (p=0.000). IFS presented reasonable agreement rates predicting postoperative PS results, including deep myometrial invasion and high-grade. IFS helps identify high-intermediate risk patients in preoperative biopsy and MRI and guides intraoperative lymphadenectomy decisions in EA.

Mapping Resection Progress by Tool-Tip Tracking during Brain Tumor Surgery for Real-Time Estimation of Residual Tumor.

Surgical resection continues to be the primary initial therapeutic strategy in the treatment of patients with brain tumors. Computerized cranial neuronavigation based on preoperative imaging offers precision guidance during craniotomy and early tumor resection but progressively loses validity with brain shift. Intraoperative MRI (iMRI) and intraoperative ultrasound (iUS) can update the imaging used for guidance and navigation but are limited in terms of temporal and spatial resolution, respectively. We present a system that uses time-stamped tool-tip positions of surgical instruments to generate a map of resection progress with high spatial and temporal accuracy. We evaluate this system and present results from 80 cranial tumor resections. Regions of the preoperative tumor segmentation that are covered by the resection map (True Positive Tracking) and regions of the preoperative tumor segmentation not covered by the resection map (True Negative Tracking) are determined for each case. We compare True Negative Tracking, which estimates the residual tumor, with the actual residual tumor identified using iMRI. We discuss factors that can cause False Positive Tracking and False Negative Tracking, which underestimate and overestimate the residual tumor, respectively. Our method provides good estimates of the residual tumor when there is minimal brain shift, and line-of-sight is maintained. When these conditions are not met, surgeons report that it is still useful for identifying regions of potential residual.