Intraoperative Magnetic Resonance Imaging Research Articles

VALUE OF INTRAOPERATIVE COMPUTED TOMOGRAPHY IN INTRAAXIAL BRAIN TUMOUR SURGERY: A SYSTEMATIC REVIEW.

Real-time intraoperative imaging with neuronavigation is a valuable adjunct in the surgical management of intra-axial brain tumours. While intraoperative magnetic resonance imaging (iMRI) is the gold standard, recent advances in technology have explored the utility of intraoperative computed tomography (iCT) as an alternative. A systematic review was conducted by searching multiple databases, including MEDLINE, PubMed, Scopus, Cochrane Library, and Web of Science, for studies published from 1982 to 2024. Studies that evaluated the use of iCT in intra-axial brain tumour surgeries and reported on outcomes such as the extent of tumour resection (EOTR), residual tumour detection, and postoperative complications were included. Thirteen studies met the inclusion criteria. Overall, recent improvements in iCT's soft tissue imaging quality have increased its utility in intra-axial brain tumour surgeries. iCT was found to improve tumour resection accuracy in some instances, helping neurosurgeons detect residual tumours and refine surgical strategies. However, conclusions about its impact on long-term outcomes are limited by the lack of data on molecular tumour characteristics and adjuvant therapies. Further high-quality prospective work is needed to validate the role of iCT in improving key outcome parameters in neuro-oncology. Until then, iCT remains an adjunct whose use can be considered in select cases. Continued research on iCT is warranted to determine further indications in intra-axial brain tumour surgery.

Use of intraoperative magnetic resonance imaging in transsphenoidal resection of pituitary adenomas: what results have been obtained?

Use of intraoperative magnetic resonance imaging in transsphenoidal resection of pituitary adenomas: what results have been obtained?

Microsurgical resection of dominant hemisphere gliomas with intraoperative speech mapping by a staff neurologist

To analyze surgical treatment of patients with glial tumors near speech and motor centers using intraoperative awakening with speech mapping by staff neurologist. We analyzed postoperative outcomes in 15 patients with dominant hemisphere gliomas of functionally significant areas between 2020 and 2024. All surgeries were accompanied by multimodal neurophysiological monitoring including intraoperative awakening and mapping by staff neurologist without neuropsychologist or neurolinguist. Intraoperative contrast-enhanced MRI was performed in 3 (20.0%) patients (T2WI and T1WI). Postoperative MRI was performed on the first postoperative day in all patients for objective assessment of resection quality. Total resection was achieved in 13 (86.7%) cases, subtotal - in 2 (13.3%) cases. In 11 (73.3%) patients, no postoperative neurological deficit was detected. Three (20.0%) patients had transient speech impairment with regression throughout a month. Persistent deficit developed in 1 (6.7%) patient. Standardized speech mapping methods and staff neurologist for cortical mapping during resection of gliomas near functionally significant speech zones maintain high extent of resection without higher risk of permanent speech disorders. Widespread speech mapping by staff neurologists of neurosurgical departments will increase the number of function-preserving surgeries in all regions of the Russian Federation.

Expandable grid, a simple, readily available and precise technique for intraoperative stereotactic real-time imaging

IntroductionPre- and postoperative imaging constitutes a firm brick in planning and steering accurate stereotactic procedures. The availability of intraoperative control measures, e.g., CT, MRI, and microelectrode recording (MER), is often limited to a minority of centers. Our approach utilizes fluoroscopy for target planning and coordinates validation as control.MethodsThis technique was primarily conceived for the RM (Riechert Mundinger) stereotactic system, but it also applies to the ZD (Zamorano—Dujovny) system. In the present study, we shifted the zero of the Z-value (axis of the patient) to + 60 mm. This corresponds to the center of the Angio/X-ray localizing plates. By assigning a radiopaque marker to the center of each plate, aligning these centers produced orthogonal and non-distorted stereotactic space. In this space, the magnification variable matters to us the most. Using available viewer software, we printed a millimetric grid on translucent foils with the corresponding magnification factor, which can easily be superimposed on the fluoroscopic image. This allows the precise validation of the coordinates of points of interest, including typical stereotactic landmarks. This technique can be used in both views, AP and lateral.ResultsWe have validated this technique under non-clinical (phantom) conditions and with intraoperative images obtained during routine stereotactic procedures. The latter were acquired using our classical stereotactic fixedly-mounted X-ray system. We found identical results, with an accuracy margin of error lower than 1 mm.ConclusionThis simple geometrical adaptation proved to be an accurate, accessible, mobile, and manageable technique providing immediate access to stereotactic coordinates during surgery. The accuracy proved to be non-inferior to other more complex and time-consuming imaging modalities.

Comparison of Echo Planar and Turbo Spin Echo Diffusion-Weighted Imaging in Intraoperative MRI.

Diffusion-weighted imaging (DWI) is routinely used in brain tumor surgery guided by intraoperative MRI (IoMRI). However, conventional echo planar imaging DWI (EPI-DWI) is susceptible to distortion and artifacts that affect image quality. Turbo spin echo DWI (TSE-DWI) is an alternative technique with minimal spatial distortions that has the potential to be the radiologically preferred sequence. To compare via single- and multisequence assessment EPI-DWI and TSE-DWI in the IoMRI setting to determine whether there is a radiological preference for either sequence. Retrospective. Thirty-four patients (22 female) aged 2-61 years (24 under 18 years) undergoing IoMRI during surgical resection of intracranial tumors. 3-T, EPI-DWI, and TSE-DWI. Patients were scanned with EPI- and TSE-DWI as part of the standard IoMRI scanning protocol. A single-sequence assessment of spatial distortion and image artifact was performed by three neuroradiologists blinded to the sequence type. Images were scored regarding distortion and artifacts, around and remote to the resection cavity. A multisequence radiological assessment was performed by three neuroradiologists in full radiological context including all other IoMRI sequences from each case. The DWI images were directly compared with scorings of the radiologists on which they preferred with respect to anatomy, abnormality, artifact, and overall preference. Wilcoxon signed-rank tests for single-sequence assessment, weighted kappa for single and multisequence assessment. A P-value <0.001 was considered statistically significant. For the blinded single-sequence assessment, the TSE-DWI sequence was scored equal to or superior to the EPI-DWI sequence for distortion and artifacts, around and remote to the resection cavity for every case. In the multisequence assessment, all radiologists independently expressed a preference for TSE-DWI over EPI-DWI sequences on viewing brain anatomy, abnormalities, and artifacts. The TSE-DWI sequences may be favored over EPI-DWI for IoMRI in patients with intracranial tumors. 2 TECHNICAL EFFICACY: Stage 5.

Does deep brain stimulation of the anterior nucleus of the thalamus represent the future of Lennox–Gastaut syndrome?

BackgroundSome studies have indicated that deep brain stimulation (DBS) of the thalamus targeting the centromedian nucleus (CMN) may reduce the frequency of seizures in Lennox–Gastaut syndrome (LGS), albeit with incomplete results. DBS targeting of the anterior nucleus of the thalamus (ANT) has demonstrated efficacy in refractory focal epilepsies and is currently FDA-approved for adult treatment. Additionally, the ANT nucleus is morphologically larger than the CMN, facilitating precise targeting and with potentially higher implantation success rates.Patients and methodsThree adult patients (one male, two females), all experiencing daily seizures that included episodes of falling, underwent ANT-DBS, one at the age of 22 years, and two at 28 years. Two electrodes were implanted under general anesthesia, using intra-operative MRI and a micro-endoscope. The clinical data regarding seizure frequency and severity, as well as cognitive function and adaptive behaviors, were collected prospectively.ResultsOne patient achieved seizure freedom 3 years post-surgery. This was confirmed by a current follow-up of 8 years after DBS, which represents a total seizure-free period of 5 years. Two patients were followed for 18 and 24 months, respectively; both achieved a seizure reduction of over 75%. All three patients demonstrated considerable improvements in adaptive behavior. No side effects (in particular psychiatric disorders) were observed with the applied therapeutic stimulation parameters.ConclusionThis series showed promising results in adult patients with LGS for both improvement of seizure frequency and adaptive behavior. The current use of pediatric thalamic stimulation is limited but the benefits shown in adults present promising prospects for its future application.

A Data-Driven Approach for Rathke's Cleft Cysts Management.

Background: Rathke's cleft cysts (RCCs) are non-neoplastic and rare sellar lesions derived from remnants of Rathke's pouch. While asymptomatic RCCs often require only conservative management, symptomatic cases may necessitate surgical intervention. The aim of our study is to investigate the correlations between clinical, radiological and histological features of RCCs to propose a novel management model. Methods: We conducted a retrospective analysis from patients who underwent surgery for cystic lesions between 2013 and 2023 in the Neurosurgery Department of Treviso Hospital (Italy) using for our purpose only those confirmed by histological specimen as RCCs. Results: 20 patients for a total of 24 procedures (20 primary surgeries/4 cases for recurrence) were performed for RCCs. A gross total resection was achieved in 23 cases, resulting in improvement of headache and visual symptoms in all patients. Hyperintensity on T1-weighted MRI sequences is more strongly correlated with inflammation and with intralesional metaplasia (p = 0.009). Both characteristics are involved in the development of hypopituitarism (p = 0.057), headache, and visual impairment (p = 0.082) compared to cysts with CSF-like content, even when the latter are smaller in size (p = 0.078). Discussion and Conclusions: RCCs are rare lesions whose management is challenging due to a lack of established guidelines. Intraoperative cystic content and MRI cystic characteristics seem to correlate with clinical presentation and long-term outcome in these patients. The transsphenoidal endoscopic approach is a safe and effective treatment, especially in cysts with inflammatory aspect in histopathological specimens and in dedicated MRI sequences that could take advantage of an early surgical resection. A decision-making model based on clinical, radiological and histopathological features of cysts could be useful to guide RCCs' treatment, underlining the role of inflammation that seems to be involved in the onset of visual and hormonal impairment and in recurrence risk.

Optimizing the use of intraoperative MRI in endoscopic resection of craniopharyngiomas: Considerations for broader applicability

Optimizing the use of intraoperative MRI in endoscopic resection of craniopharyngiomas: Considerations for broader applicability

Can posterior fossa decompression alone effectively treat Chiari malformation type I patients with even severe syringes? Illustrative cases.

The benefit of posterior fossa decompression (PFD) alone (without duraplasty) for Chiari malformation type I (CM-I) remains controversial. Many neurosurgeons still open the dura when a syrinx is present, particularly for what appears to be a severe syrinx. Based on the existing literature, the authors hypothesized that even a severe syrinx would respond well to a PFD alone. In a proof-of-principle study, the authors prospectively included 4 patients with CM-I, aged 3-15 years, with severe symptomatic syringes (spanning multiple cervical/thoracic levels and/or focally expanding the spinal cord) to undergo PFD with pre- and postdissection intraoperative MRI (iMRI). In all cases, same-day postdissection iMRI cine images showed enhanced CSF flow compared with predissection iMRI findings. Three of the 4 patients showed early syrinx and symptom improvement (≤ 6 weeks); all showed improvements at long-term follow-up (≥ 2 years). The mean hospital length of stay (LOS) was 1.25 days, with no complications or repeat surgery needed, and the mean follow-up was 37.5 months. CM-I can be treated via PFD alone without duraplasty, even with a severe syrinx. Improved CSF flow is achieved intraoperatively, and the syrinx can significantly decrease over a 6-week to 1-year period postoperatively. Additional benefits include a low risk of complications and a short LOS. https://thejns.org/doi/10.3171/CASE24777.

Giant pediatric brainstem cavernoma: illustrative case.

Cerebral cavernous malformations are low-flow vascular lesions and the most common of all vascular pathologies encountered by neurosurgeons. The location of these lesions is critically important in determining the symptomatology and whether intervention is indicated. Cavernous malformations localized to the brainstem are often the most complex of these to manage given the density of critical structures and tracts found within the brainstem. Here, the authors present the case of a 3-year-old male who presented with hemiparesis and eventually developed hydrocephalus from a giant brainstem cavernous malformation. The patient initially did well on steroids but had a recurrent hemorrhage that led to worsening hemiparesis and hydrocephalus. The authors then elected to resect the cavernous malformation via a supracerebellar infratentorial approach utilizing intraoperative MRI to ensure complete resection. Postoperatively, the patient returned to near baseline neurological function. The authors describe an uncommon approach to the management of a pediatric patient with a giant brainstem cavernous malformation by carefully examining the potential approaches and utilizing available technologies to ensure an excellent outcome for the patient. https://thejns.org/doi/10.3171/CASE24814.

Intraoperative Magnetic Resonance Imaging in Pituitary Surgery

Intraoperative magnetic resonance imaging (iMRI) improves the pituitary adenoma resection rate (GTR) by detecting small residual tumors and enabling additional resection. Consequently, complete resection is easier to achieve during the initial surgery, which reduces the risk of reoperation. However, the introduction and maintenance of iMRI implies high costs and extended surgical time. In the United States, estimates suggest that the long-term introduction of iMRI in pituitary surgery may lead to cost savings. Further research is needed to explore the added value of iMRI for pituitary surgeries beyond GTR and clarify the criteria for selecting cases that would benefit from iMRI.

Image-guided Brain Tumor Surgery with Intraoperative MRI

Intraoperative MRI (iMRI) is an invaluable modality that enhances quality control and assurance in neurosurgical procedures. Its principal function is to recalibrate navigational datasets, compensating for brain shift and ensuring optimal surgical precision throughout the procedure. Additionally, iMRI facilitates the intraoperative assessment of surgical endpoints, such as confirming the extent of resection and verifying whether gross total resection has been achieved. Moreover, it plays a pivotal role in detecting occult intraoperative complications, including intraprocedural hemorrhage, which might not be evident through direct visual assessment alone. In glioma surgery, the integration of iMRI significantly improves resection quality and may lead to prolonged overall and progression-free survival. This has led to recommending iMRI in established U.S. clinical guidelines. Stringent adherence to magnetic field safety protocols is paramount when implementing iMRI systems. It is crucial to prohibit the presence of ferromagnetic surgical instruments and use of MR-compatible devices within the 5-gauss line to avoid potentially catastrophic projectile incidents or equipment malfunctions. Furthermore, establishing comprehensive institutional protocols and rigorous training programs for all personnel is mandatory to ensure compliance with safety standards and maintain procedural integrity.

Using Futuristic Advanced Operating Rooms

Future operating rooms (ORs) should integrate cutting-edge technologies to address the limitations of traditional surgical environments. Leveraging intraoperative imaging, the Internet of Things, and artificial intelligence enables real-time data integration, precise decision-making, and improved surgical outcomes. This approach transforms implicit knowledge into structured and actionable insights, thereby enhancing efficiency. Technologies, such as intraoperative magnetic resonance imaging, hybrid ORs, and surgical robots offer advanced capabilities, reduce complications, and standardize surgical performance. Remote surgery and telemonitoring extend expert care to underserved regions, addressing geographical disparities. However, challenges such as high implementation costs, data security, and standardization, persist. International efforts, such as OPeLiNK, aim to standardize data protocols and interoperability. Future ORs are envisioned as dynamic and intelligent environments that can adapt to complex needs, ensuring enhanced patient safety, clinical outcomes, and equitable healthcare delivery.

Effective Use of Evolutionary Operating Room

Brain parenchyma tumors, typically gliomas, often arise in eloquent areas and complex regions deep within the brain that are involved in language, motor, and higher cognitive functions. Brain tumor surgery aims to safely remove as much of the tumor as possible while preserving brain function. However, invasive brain tumors, such as gliomas, are often difficult to distinguish from the normal brain, and removal of the entire tumor may inadvertently damage the normal brain tissue, resulting in the risk of serious postoperative complications. Additionally, brain tissue is subject to brain deformation, called brain shift, because of cerebrospinal fluid drainage and tumor removal. This reduces the accuracy of neuronavigation during preoperative planning, resulting in differences in the exact locations of the tumor and nerve fibers. Intraoperative magnetic resonance imaging (MRI) enabled to identify the exact tumor position and residual tumor in real-time perioperatively, compared to surgery that relies on the surgeon's experience and skill, enabling highly accurate surgery. Moreover, the fusion and comparison of preoperative images and latest intraoperative MRI images enable the accurate evaluation of tumor location and safe tumor removal. Intraoperative MRI imaging-assisted techniques that can capture residual tumor morphology and awake surgery that preserves brain function should be integrated to complement each other's roles.

Intraoperative Supine Breast MRI for Residual Tumor Assessment after Breast-Conserving Therapy in Early-Stage Breast Cancer.

Purpose To evaluate the diagnostic performance of intraoperative supine MRI (isMRI) in identifying residual tumor burden immediately after breast-conserving therapy (BCT). Materials and Methods This single-institution prospective study (April 2012-December 2022) included 43 consecutive participants with stage 0-II breast cancer. Three participants with multicentric disease were excluded from the final analysis. Preoperative supine MRI was performed after standard preoperative prone MRI to compare tumor sizes and distances to the nipple, chest wall, and skin. After lumpectomy, the saline-filled surgical cavity was assessed for residual tumor at 3-T isMRI in the operating suite. Diagnostic accuracy of isMRI findings in identifying residual tumor at resection margins was assessed using histopathology of shave margin specimens as the reference standard. Performance metrics of isMRI and re-excision rates were analyzed at per-participant and per-margin levels. Results Forty participants (median age, 58.5 years; range, 40-76 years) with 44 breast cancers (36 unifocal and four multifocal) underwent BCT, all with a single lumpectomy site. Margin assessment using isMRI yielded accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 80%, 50%, 93%, 75%, and 81% per participant, respectively; and 93%, 52%, 97%, 65%, and 96% per margin. Second re-excision was avoided in two of six (33%) participants with true-positive isMRI readings, decreasing the final re-excision rate from 18% to 13%. Histopathology of six false-negative isMRI cases revealed residual invasive carcinomas, all smaller than 0.3 cm, or intermediate-to-high grade ductal carcinoma in situ. Conclusion Intraoperative assessment for residual tumor after BCT using isMRI demonstrated promising accuracy to guide targeted margin clearance within the same operation. Keywords: Breast, MR-Imaging, MR-Dynamic Contrast Enhanced, Oncology Supplemental material is available for this article. © RSNA, 2025.

Use of Intraoperative Images and Surgical Videos in Neurosurgery:Challenges and Future Prospects

In recent years, advancements in intraoperative imaging technology, surgical visualization systems, Artificial Intelligence (AI), and robotic-assisted technologies have significantly improved the precision, safety, and postoperative outcomes of neurosurgical procedures. Surgical simulation contributes to optimizing preoperative planning and enhancing the skills of young surgeons, while navigation technologies, utilizing optical or magnetic systems, enhance the accuracy of tumor resection. Intraoperative MRI and CT provide real-time assessment of residual tumors and vascular structures, and the integration of AI allows high-resolution imaging even with low-field MRI systems. Neuroendoscopes and exoscopes equipped with 4K resolution or 3D technology have improved visual precision, while AI aids in tumor boundary identification and postoperative outcome prediction. The integration of robotic technology further enhances surgical accuracy. However, challenges remain, including high implementation costs, inadequate reimbursement systems, insufficient evidence, and a lack of standardized operational guidelines. Integrating and standardizing these technologies will enhance surgical safety, precision, and efficiency, improve patient outcomes, and optimize healthcare workflows, necessitating policy reforms and robust evidence-based frameworks.

Brain surgery with safe intraoperative 3-T MRI and neuromonitoring.

The aim in glioma or glioblastoma neurosurgery is maximal safe resection, knowing patient survival is strongly linked to resection extension. Deliberately leaving scalp subdermal neuromonitoring needle electrodes in place during intraoperative MRI is highly desirable for continued surgery after MRI but raises concerns for safety and image quality. Preclinical tests were performed to determine safe neuromonitoring electrodes and imaging protocols. The first implementations in a consecutive patient series are reported. Electromagnetic coupling between electrodes and MR radiofrequency pulses was measured for 5 different electrode lengths via local changes in the B1 field and temperature elevation around the electrode needle. Once the electrode length was selected, specific absorption rate (SAR) thresholds were determined and applied in the first 12 patients who gave consent. All subdermal scalp needle electrodes required for motor, somatosensory, or brainstem auditory or visual evoked potentials were carefully located perpendicular to the B0 field axis and remained in place. Electrode wires were kept in an axial position as close as possible along the center of the MR magnet tunnel to avoid any loops or crossing. The temperature elevation (mean ± SD 0.49°C ± 0.02°C), coupling (2.25 AngularDegree2.cm2), and minimum wire length for accessing the neuromonitoring head box determined the electrode length (1360 mm). Five to 9 scalp electrodes were kept in place during MRI. Among 12 patients, 6 did not require further SAR limitation below the standard regulation of 2 W/kg. The SAR limit of 1.0 W/kg was safe. Lesion resection was continued after MRI in 3 patients; motor monitoring was reinstalled in 1 patient (frontal glioblastoma). Neither redness nor any sign of burns or complaints were detected. Neither radiofrequency spikes nor significant susceptibility artifacts were observed. This protocol, which included a semiempirical physical model, in situ thermometry, B1 mapping, and cutoff SAR thresholding for controlled electrode length and positioning, was safe for intraoperative 3-T MRI in brain surgical procedures in routine clinical practice.

Deep learning-based Intraoperative MRI reconstruction

BackgroundWe retrospectively evaluated the quality of deep learning (DL) reconstructions of on-scanner accelerated intraoperative MRI (iMRI) during respective brain tumor surgery.MethodsAccelerated iMRI was performed using dual surface coils positioned around the area of resection. A DL model was trained on the fastMRI neuro dataset to mimic the data from the iMRI protocol. The evaluation was performed on imaging material from 40 patients imaged from Nov 1, 2021, to June 1, 2023, who underwent iMRI during tumor resection surgery. A comparative analysis was conducted between the conventional compressed sense (CS) method and the trained DL reconstruction method. Blinded evaluation of multiple image quality metrics was performed by two neuroradiologists and one neurosurgeon using a 1-to-5 Likert scale (1, nondiagnostic; 2, poor; 3, acceptable; 4, good; and 5, excellent), and the favored reconstruction variant.ResultsThe DL reconstruction was strongly favored or favored over the CS reconstruction for 33/40, 39/40, and 8/40 of cases for readers 1, 2, and 3, respectively. For the evaluation metrics, the DL reconstructions had a higher score than their respective CS counterparts for 72%, 72%, and 14% of the cases for readers 1, 2, and 3, respectively. Still, the DL reconstructions exhibited shortcomings such as a striping artifact and reduced signal.ConclusionDL shows promise in allowing for high-quality reconstructions of iMRI. The neuroradiologists noted an improvement in the perceived spatial resolution, signal-to-noise ratio, diagnostic confidence, diagnostic conspicuity, and spatial resolution compared to CS, while the neurosurgeon preferred the CS reconstructions across all metrics.Relevance statementDL shows promise to allow for high-quality reconstructions of iMRI, however, due to the challenging setting of iMRI, further optimization is needed.Key PointsiMRI is a surgical tool with a challenging image setting.DL allowed for high-quality reconstructions of iMRI.Additional optimization is needed due to the challenging intraoperative setting.Graphical

Pediatric cerebral ganglioglioma epilepsy surgery: enhancing seizure outcomes through optimized resection applying high-field intraoperative magnetic resonance imaging.

Gangliogliomas are rare, slow-growing brain tumors frequently associated with seizures in pediatric patients. This study evaluated the utility of high-field intraoperative magnetic resonance imaging (ioMRI) in the surgical management of ganglioglioma-related drug-resistant epilepsy in children. Specifically, it sought to determine whether ioMRI improves outcomes by optimizing the extent of resection, enhancing seizure control, reducing reoperations, and minimizing complications. This retrospective single-center study included 14 pediatric patients with cerebral ganglioglioma who underwent epilepsy surgery with ioMRI from 2014 to 2022. The median age was 11.5years (range 3-16years). Patient demographics, the rate of continued ioMRI-guided surgery, the extent of resection, histology, complications, reoperations, and seizure outcomes at 1year postoperatively were assessed. Residual tumor was detected using ioMRI in 9 of 14 patients (64.3%), leading to further resection. Complete tumor resection was achieved in 12 patients (100%) as intended, while two patients underwent planned tumor debulking. Temporary neurological deficits were observed in two patients, with no permanent deficits documented. One patient required reoperation, and another was scheduled for one. The median follow-up duration was 43months (range 12-65months). Seizure outcomes were classified as Engel I in 9 of 10 (90%) and Engel III in 1 of 10 patients (10%). Four patients were lost to follow-up. The use of ioMRI in pediatric epilepsy surgery for ganglioglioma facilitated more complete resections, contributing to favorable seizure outcomes and a low complication rate. These findings support ioMRI as a valuable tool in optimizing surgical management for this patient population.

Pushing the boundaries of neurosurgical oncology: evaluating the superiority of supratotal resection over gross total resection in intraoperative MRI-guided glioma surgery

Using intraoperative MRI (iMRI) in glioma surgery can enhance the extent of resection (EOR) and improve survival rates for patients diagnosed with low grade gliomas (LGG) or high grade gliomas (HGG). This study focused on patients who underwent iMRI-guided surgery for LGG and HGG at our center. Our objective was to compare the patient survival time and recurrence rate between supratotal resection (SpTR) and gross total resection(GTR). To the best of our knowledge, this is the first study comparing SpTR with GTR using iMRI in glioma surgery. This study included 71 patients who had undergone iMRI-guided GTR and SpTR. The volume of the tumors was measured using postcontrast 3D T1W series and 3D FLAIR series taken the day before surgery, and the volume of the operation cavity was calculated from iMRI images. The effects of SpTR and GTR on overall and progression-free survival (OS and PFS) were analyzed by the log-rank test using Kaplan‒Meier curves. The associations between the extent of resection and tumor grade, and between recurrence and tumor grade were examined using the chi-square test. The rate of recurrence in patients diagnosed with HGG was greater than that in patients diagnosed with LGG (p = 0.022). While patients who received SpTR had a greater OS time (105.9 months) than did those who underwent GTR (92.8 months), the difference was not statistically significant. The patients with LGG had a significantly longer PFS time than did the patients with HGG (86.5 ± 5.9 months, 95% CI = 74.9–98.2, p < 0.0001). Of 23 patients diagnosed with HGG, SpTR was achieved in 9 and GTR was achieved in 14. The median OS time was longer in patients who underwent SpTR than in those who underwent GTR, but there was no statistically significant difference [101.2 ± 20.5 months (95% CI: 80.7–121.7) vs. 70.6 ± 9.9 (95% CI: 60.7–80.5) p = 0.9]. Neurosurgeons are increasingly choosing SpTR, especially in LGGs. Despite their slow growth, LGGs retain the potential for malignant transformation. This situation underscores the importance of maximum safe resection in the surgery of LGGs. iMRI-guided resection makes it easier for surgeons to show the EOR concurrent with the operation.