Characterization of tumor remnants in intraoperative MRI-assisted microscopic and endoscopic transsphenoidal resection of less invasive pituitary adenomas.

INTRODUCTION: Intraoperative magnetic resonance imaging (iMRI) improves the intraoperative detection of adenoma remnants in transsphenoidal surgery. iMRI might be redundant in endoscopic pituitary surgery in non-invasive tumors (Knosp 0-2) due to a superior visualization of anatomical structures in the periphery of the sella turcica compared to the microscopic technique. We identified the anatomical location of tumor remnants in iMRI and evaluated risk factors for secondary resection after iMRI and hereby selected patients with pituitary adenomas who may benefit from iMRI-assisted resection. METHODS: We conducted a retrospective monocenter study of patients who underwent iMRI-assisted transsphenoidal surgical resection of pituitary adenomas at our department between 2012 and 2020. A total number of 190 consecutive iMRI-assisted transsphenoidal surgeries of pituitary adenomas graded as Knosp 0-2 were selected for analysis. Exclusion criteria were missing iMRI availability or pathologies other than adenomas. Of these 190 cases, 46.3% (N = 88) were treated with microscopic, 48.4% (N = 92) with endoscopic, and 5.3% (N = 10) with endoscopic-assisted technique. Volumetric measurement of preoperative, intraoperative, and postoperative tumor extension was performed. Demographic data, tumor characteristics, and MRI features were evaluated. Additionally, analysis of adenoma remnants identified by iMRI was performed. RESULTS: An additional resection after iMRI was performed in 16.3% (N = 31). iMRI helped to reach gross total resection (GTR) in 83.9% (26/31) of these cases. False-positive resection was found in 1 patient (0.5%). Multivariable logistic analysis identified tumor volume (OR = 1.2, p = 0.007) recurrence (OR = 11.3, p = 0.002) and microscopic technique (OR = 2.8, p = 0.029) as independent risk factors for additional resection. Simultaneously, the endoscopic technique was significantly associated with GTR as evaluated by iMRI (OR = 2.8, p = 0.011) and postoperative MRI (OR = 5.8, p = 0.027). The detailed analysis of adenoma remnants on iMRI revealed the suprasellar location in a diaphragm fold, penetrating tumor above the diaphragm, or undetected invasion of cavernous sinus as well as in case of microscopic resection tumor location outside the line of sight as the main reasons for incomplete resections. CONCLUSION: Tumor volume, recurrence, and microscopic technique were identified as independent predictors for additional resection in patients with Knosp 0-2 adenomas. iMRI might increase the extent of resection (EOR) safely even after the endoscopic visualization of the sella with very low risk for false-positive findings. Remnants of tumors hidden within the diaphragmic folds, intrathecally, or behind the infiltrated wall of cavernous sinus not recognized on preoperative MRI were the most common findings in iMRI.

Towards the targeted assessment of relevant problems: Optimization of the distress Thermometer for adult neuro-oncological patients.

OBJECTIVE: Generic psychosocial screening tools may not reflect the unique symptom profile of brain tumour patients (BTPs). The aim was to adapt the problem list of the distress thermometer (DT) for BTPs. METHODS: First, items of low relevance for BTPs were identified on basis of retrospective analyses. Second, relevant yet missing problems were identified via an extensive literature search, qualitative interviews with BTPs and experts, as well as an online expert survey. The resulting raw version of the adapted problem list in BTPs was subsequently pretested. RESULTS: In the first part, data of n = 657 BTPs were analysed. Twelve items (20%) were excluded in this step as they proved to be less relevant for BTPs (i.e., items were endorsed by less than 10% and without significant correlations to patients' DT score). In the second part, qualitative interviews and the online survey with 102 professionals led to the addition of 21 new and the modification and condensation of 17 relevant problems specific for BTPs. This adapted list was than successfully pretested in n = 19 patients, leading to the 'distress thermometer brain tumour problem list' (DT-BT), consisting of 42 relevant problems. CONCLUSION: The adapted problem list for the DT particularly reflects the neurological and psychosocial burden of an intracranial tumour and allows for the targeted assessment of the specific burdens and needs of BTPs. Our revised version of the DTs problem list (DT-BT) should in the next step be widely validated in multinational samples.

Health-related quality of life and distress in elderly vs. younger patients with high-grade glioma-results of a multicenter study.

OBJECTIVE: Half of all newly diagnosed patients with glioblastoma are > 65 years still with a poor prognosis. Preserving quality of life is of high importance. However, patient reported outcome (PRO) data in this patient group is rare. The aim was to compare health-related quality of life (HRQoL) and distress between elderly and younger patients with high-grade glioma (HGG). METHODS: We used baseline data of a prospective study where HGG patients were enrolled from 4 hospitals. Distress was measured using the distress thermometer (DT), HRQoL using the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Core Questionnaire (QLQ-C30) plus brain module (BN20). We compared distress and HRQoL by age (≥ 65 vs. < 65 years), gender, performance score, and time since diagnosis using multivariate linear and logistic regressions. RESULTS: A total of n = 93 (30%) out of n = 309 patients were ≥ 65 years (mean 70 years, range 65-86 years). Mean DT score of elderly patients (5.2, SD 2.6) was comparable with younger patients (4.9, SD 2.6). Elderly patients reported significantly lower global health (GHS, mean elderly vs. younger; 50.8 vs. 60.5, p = 0.003), worse physical (56.8 vs. 73.3, p < 0.001) and lower cognitive functioning (51.1 vs. 63.2, p = 0.002), worse fatigue (52.5 vs. 43.5, p = 0.042), and worse motor dysfunction (34.9 vs. 23.6, p = 0.030). KPS and not age was consistently associated with HRQoL. CONCLUSION: Physical functioning was significantly reduced in the elderly compared with younger HGG patients, and at the same time, emotional functioning and DT scores were comparable. KPS shows a greater association with HRQoL than with calendric age in HGG patients reflecting the particular importance for adequate assessment of HRQoL and general condition in elderly patients.

Ten years' experience with intraoperative MRI-assisted transsphenoidal pituitary surgery.

OBJECTIVE: Many innovations have been introduced into pituitary surgery in the quest to maximize the extent of tumor resection. Because of the deep and narrow surgical corridor as well as the heterogeneity of confronted pathologies, anatomical orientation and identification of the target tissue can become difficult. Intraoperative MRI (iMRI) may have the potential to increase extent of resection (EOR) in transsphenoidal pituitary surgery. Furthermore, it may simplify anatomical orientation and risk assessment in difficult cases. Here, the authors evaluated the additional value of iMRI for the resection of pituitary adenomas performed in the past 10 years in their department. METHODS: They performed a retrospective single-center analysis of patients treated for pituitary adenoma in their department after the introduction of iMRI between 2008 and 2018. Of 495 transsphenoidal approaches, 300 consecutive MRI-assisted surgeries for pituitary adenomas encompassing 294 patients were selected for further analysis. Microscopic, endoscopic, or endoscope-assisted microscopic transsphenoidal approaches were distinguished. EOR as well as additional resection following iMRI was evaluated via detailed volumetric analysis. Patients were stratified according to the Knosp adenoma classification. Furthermore, demographic data, clinical symptoms, endocrine outcome, and complications were evaluated. Univariable and multivariable Cox regression analyses of progression-free survival (PFS) were performed. RESULTS: Pituitary adenomas classified as Knosp grades 0-2 were found in 60.3% of cases (n = 181). The most common tumors were nonfunctioning adenomas (75%). Continued resection following iMRI significantly increased EOR (7.5%, p < 0.001) and the proportion of gross-total resections (GTRs) in transsphenoidal pituitary surgery (54% vs 68.3%, p < 0.001). Additional resection after iMRI was performed in 37% of cases. Only in the subgroup of patients with Knosp grades 0-2 adenomas treated with the microsurgical technique was additional resection significantly more common than in the endoscopic group (p = 0.039). Residual tumor volume, Knosp grade, and age were confirmed as independent predictors of PFS (p < 0.001, p = 0.021, and p = 0.029, respectively) in a multivariable Cox regression analysis. Improvement of visual field deficits was documented in 78.6% of patients whose optic apparatus had been affected preoperatively. Revision surgery was done in 7.3% of cases; in 5.6% of cases, it was performed for cerebrospinal fluid fistula. CONCLUSIONS: In this series, iMRI led to the detection of a resectable tumor remnant in a high proportion of patients, resulting in a greater EOR and higher proportion of GTRs after continued resection in microsurgical and endoscopic transsphenoidal resection of pituitary adenomas. The volume of residual tumor was the most important predictor of PFS. Given the study data, the authors postulated that every bit of removed tumor serves the patient and increases their chances of a favorable outcome.

Fluorescence guided surgery by 5-ALA and intraoperative MRI in high grade glioma: a systematic review.

PURPOSE: Fluorescence guided surgery by 5-aminolevulinic acid (5-ALA) and intraoperative MRI (iMRI) are currently the most important intraoperative imaging techniques in high grade glioma (HGG) surgery. Few comparative studies exist for these techniques. This review aims to systematically compare 5-ALA and iMRI assisted surgery based on the current literature and discuss the potential impact of a combined use of both techniques. METHODS: A systematic literature search based on preferred reporting items for systematic reviews and meta-analysis was performed concerning accuracy of tumor detection; extent of resection; neurological deficits (ND); Quality of life (QoL); usability and combined use of both techniques. Original clinical articles on HGG published until March 31st were screened. RESULTS: 169 publications were screened, 81 were eligible and 22 were finally included in the review using. Overall, there is evidence that both imaging techniques improve gross total resection rate in non-eloquent lesions. Imaging results do not correlate at the border zone of a HGG. 5-ALA and contrast-enhanced iMRI seem to have a supplementary effect in tumor detection. Overall, both imaging techniques alone or combined do not seem to increase rate of permanent ND or decrease QoL in HGG surgery when used with intraoperative monitoring/mapping. CONCLUSION: Based on the currently available literature no superiority of one technique over the other can be found in the most important outcome parameters. Based on the available information a combined use of 5-ALA and iMRI seems very promising to achieve a resection beyond gadolinium-enhancement. However, only low quality of evidence exists for this approach.

Diagnostic accuracy of intraoperative perfusion-weighted MRI and 5-aminolevulinic acid in relation to contrast-enhanced intraoperative MRI and 11C-methionine positron emission tomography in resection of glioblastoma: a prospective study.

The aim of our study was to compare depicted pre-, intra-, and postoperative tumor volume of met-PET, perfusion-weighed MRI (PWI), and Gd-DTPA MRI. Further, to assess their sensitivity and specificity in correlation with histopathological specimen. Inclusion criteria of the prospective study were histological confirmed glioblastoma (GB), age > 18, and eligible for gross total resection (GTR). Met-PET was performed before and after surgery. Gd-DTPA MRI and PWI were performed before, during, and after surgery. A combined 5-aminolevulinic acid (5-ALA) and iMRI-guided surgery was performed. Volumetric analysis was evaluated for all imaging modalities except for 5-ALA. A total of 59 navigated biopsies were taken. Sensitivity and specificity were calculated for Gd-DTPA MRI, PWI, met-PET, and 5-ALA according to the histology of specimen. Met-PET depicted significantly larger tumor volume before surgery (p = 0.01) compared to PWI and Gd-DTPI MRI. We found no significant difference in tumor volume between met-PET and PWI after surgery (p = 0.059). Both PWI and met-PET showed significantly larger tumor volume after surgery when compared to Gd-DTPA (p = 0.018 and p = 0.003, respectively). Intraoperative PWI reading was impaired in 33.3% due to artifacts. Met-PET showed the highest sensitivity for detection of GB with 95%. The lowest sensitivity was found with Gd-DTPA MRI (50%), while 5-ALA and intraoperative PWI showed similar results (69 and 67%). Met-Pet is the imaging modality with the highest sensitivity to detect a residual tumor in GB. Intraoperative PWI seems to have a synergistic effect to Gd-DTPA and 5-ALA. However, its value may be limited by artifacts. Both pre- and intraoperative PWI cannot substitute met-PET in tumor detection.

Intraoperative MRI in transsphenoidal resection of invasive pituitary macroadenomas.

The use of intraoperative MRI (iMRI) increases extent of resection in transsphenoidal pituitary surgery. Microsurgical and endoscopic techniques have been established as equal and standard surgical methods. The object of the current study was to evaluate the additional value of iMRI for resection of invasive pituitary adenomas. We conducted a retrospective monocenter study of all consecutive patients treated with invasive pituitary adenomas graded as Knosp III-IV at our department after the introduction of iMRI in 2008. Out of 315 transsphenoidal surgeries for pituitary adenomas, 111 met the criteria for analysis. Patients treated with endoscopic or microsurgical technique were included. iMRI was performed at surgeons' discretion, when maximal safe resection was assumed. Detailed volumetric tumor analysis using semiautomatic segmentation software (Brainlab Elements) before surgery, during surgery, and after surgery was performed. Additionally, demographic data, additional resection, endocrinological outcome as well as complications were evaluated. Postoperative tumor volume as measured in the follow-up MRI 3 months after surgery was significantly lower compared with intraoperative tumor volume (p < 0.001). The difference was statistically significant for both surgical techniques (p < 0.001). No significant difference was found between both techniques in intraoperative and postoperative tumor volume (p = 0.395 and p = 0.329 respectively). Additional tumor resection was performed in 56 cases (50.5%). We found no significant difference between microsurgical and endoscopic techniques regarding additional resection after iMRI (p = 0.512). New diagnosed permanent diabetes insipidus was found in 10 patients (10.5%, 10/95). New hypopituitarism was seen in 22.1% (21/95) cases and according to multivariate logistic regression was significantly associated with microsurgical technique (p = 0.035). Visual improvement was achieved in 76.8% (N = 53/69, p < 0.001) of patients with visual impairment before surgery. Revision surgery as the consequence of cerebrospinal fistula was performed in eight cases (7.2%). Meningitis was documented in three patients (2.7%). One patient died as a consequence of intraoperative vascular injury. Intraoperative MRI after maximal safe resection significantly improves the overall extent of resection in invasive pituitary adenomas independent of the surgical technique employed. Simultaneously, iMRI-assisted transsphenoidal surgery results in excellent visual recovery with low-risk profile for surgical complications for both endoscopic as well as microsurgical technique. Endoscopic technique might be related to the lower incidence of new hypopituitarism after surgery.

The patients' view: impact of the extent of resection, intraoperative imaging, and awake surgery on health-related quality of life in high-grade glioma patients-results of a multicenter cross-sectional study.

The objective of the present study is to assess the influence of extent of resection (EoR), use of intraoperative imaging, and awake surgery on health-related quality of life (HRQoL) in high-grade glioma (HGG) patients in a prospective multicenter study. We analyzed 170 surgeries of patients suffering from a HGG. During the first year after resection, HRQoL was evaluated using the European Organization of Research and Treatment of Cancer Core Questionnaire C30 and Brain Neoplasm 20 questionnaires. We assessed the influence of EoR; awake surgery; and use of 5-aminolevulinic acid (5-ALA), intraoperative MRI (iMRI), and their combination on sum scores for function and symptoms as well as several neurological single items. In mixed-model analyses, adjustments for age, Karnofsky performance status (KPS), and eloquent location were performed. In the mixed model, EoR generally did not significantly influence HRQoL (p = 0.10). Yet, patients receiving subtotal resection (STR) vs. patients with biopsy showed significantly better QoL and role and cognitive functions (p = 0.04, p = 0.02, and p < 0.01, respectively). The combination of iMRI and 5-ALA reached the highest EoR (95%) followed by iMRI alone (94%), 5-ALA alone (74%), and no imaging (73%). Thereby, neurological symptoms were lowest and functioning score highest after combined use of iMRI and 5-ALA, without reaching significance (p = 0.59). Despite lower scores in emotional function (59 vs. 46, p = 0.24), no significant impact of awake surgery on HRQoL was found (p = 0.70). In HGG patients, STR compared to biopsy was significantly associated with better HRQoL and fewer neurological symptoms in this series. An escalated use of intraoperative imaging increased EoR with stable or slightly better HRQoL and fewer neurological symptoms. Based on HRQoL, awake surgery was a well-tolerated and safe method in our series.

Factors associated with supportive care needs in glioma patients in the neuro-oncological outpatient setting.

Objective of this study aimed at assessing glioma patients' supportive care needs in a neurosurgical outpatient setting and identifying factors that are associated with needs for support. In three neuro-oncological outpatient departments, glioma patients were assessed for their psychosocial needs using the Supportive Care Needs Survey short-form (SCNS-SF34-G). Associations between clinical, sociodemographic, treatment related factors as well as distress (measured with the distress thermometer) and supportive care needs were explored using multivariable general linear models. One-hundred and seventy three of 244 eligible glioma patients participated, most of them with primary diagnoses of a high-grade glioma (81%). Highest need for support was observed in 'psychological needs' (median 17.5, range 5-45) followed by 'physical and daily living needs' (median 12.5, range 0-25) and 'health system and information needs' (median 11.3, range 0-36). Needs in the psychological area were associated with distress (R2 = 0.36) but not with age, sex, Karnofsky performance status (KPS), extend of resection, currently undergoing chemotherapy and whether guidance during assessment was offered. Regarding 'health system and information needs', we observed associations with distress, age, currently undergoing chemotherapy and guidance (R2 = 0.31). In the domain 'physical and daily living needs' we found associations with KPS, residual tumor, as well as with distress (R2 = 0.37). Glioma patients in neuro-oncological departments report unmet supportive care needs, especially in the psychological domain. Distress is the factor most consistently associated with unmet needs requiring support and could serve as indicator for clinical neuro-oncologists to initiate support.

Evaluating patients for psychosocial distress and supportive care needs based on health-related quality of life in primary brain tumors: a prospective multicenter analysis of patients with gliomas in an outpatient setting.

The association between health-related quality of life (HRQoL), psychosocial distress, and supportive care is in the focus of patient-centered neuro-oncology. We investigated the relationship between the aforementioned in glioma-patients to evaluate the association of these instruments and determine cut-off values for suitable HRQoL scales indicating a potential need for intervention. In an observational multi-center study, outpatients completed the Distress Thermometer (DT), EORTC Quality of Life Questionnaire (EORTC-QLQ-C30/BN20, HRQoL), and Supportive-Care-Needs-Survey-SF34-G (SCNS). Based on nine EORTC-function and selected -symptom scales items of the questionnaires were matched. Convergent validity of related single items and scores across the instruments was estimated. EORTC cut-off values were calculated. Data of 167 patients were analyzed. The strongest correlation of EORTC-QLQ-C30 and DT was found for cognitive function (cogf), global health status (GHS), emotional (emof), role function (rolef), future uncertainty (FU), fatigue, and between EORTC-QLQ-C30 and SCNS for FU, emof, rolef (r = |0.4-0.7|; p < 0.01). EORTC cut-off values of <54.2 (GHS/QoL) and <62.5 (emof) predicted a DT ≥ 6 (AUC 0.79, 0.85, p < 0.01). EORTC cut-off values of <70.8 (emof) and <52.8 (FU) predicted the need for supportive care (AUC 0.78, 0.85; p < 0.01). Worse EORTC-C30 scores correlate with higher DT and SCNS scores. With this exploratory assessment, cut-off values for EORTC-C30 subscores to predict distress and pathological SCNS-scores could be determined, which could influence patients' referral to further treatment. However, further prospective clinical trials are needed to confirm the clinical relevance of these cut-off values.

Sensitivity and specificity of linear array intraoperative ultrasound in glioblastoma surgery: a comparative study with high field intraoperative MRI and conventional sector array ultrasound.

INTRODUCTION: Linear array intraoperative ultrasound (lioUS) is an emerging technology for intracranial use. We evaluated sensitivity and specificity of lioUS to detect residual tumor in patients harboring a glioblastoma. METHODS: After near total resection in 20 patients, residual tumor detection using lioUS, conventional intraoperative ultrasound (cioUS), and gadopentetic-diethylenetriamine penta-acetic acid (Gd-DTPA)-enhanced intraoperative MRI (iMRI) were compared. Sensitivity and specificity were calculated based on 68 navigated biopsies. Receiver operator characteristic (ROC) curves and correlation with histopathological findings of each imaging modality were calculated. Additionally, results were evaluated in the subgroup of recurrent disease (23 biopsies in 8 patients). RESULTS: Sensitivity of lioUS (76 %) was significantly higher compared with iMRI (55 %) and cioUS (24 %). Specificity of lioUS (58 %) was significantly lower than in cioUS (96 %), while there was no significant difference to iMRI (74 %). All imaging modalities correlated significantly with histopathological findings. In the subgroup of recurrent disease, sensitivity and specificity decreased in all modalities. However, cioUS showed significant lower values than iMRI and lioUS. In ROC curves, lioUS showed a higher area und the curve (AUC) in comparison with iMRI and cioUS. We found similar results in the subgroup of recurrent disease. CONCLUSION: Tumor detection using a lioUS is significantly superior to cioUS. Overall test performance in lioUS is comparable with results of iMRI. While, the latter has a higher specificity and a significantly lower sensitivity in comparison with lioUS.

Linear array ultrasound in low-grade glioma surgery: histology-based assessment of accuracy in comparison to conventional intraoperative ultrasound and intraoperative MRI.

INTRODUCTION: In low-grade glioma (LGG) surgery, intraoperative differentiation between tumor and most likely tumor-free brain tissue can be challenging. Intraoperative ultrasound can facilitate tumor resection. The aim of this study is to evaluate the accuracy of linear array ultrasound in comparison to conventional intraoperative ultrasound (cioUS) and intraoperative high-field MRI (iMRI). METHODS: We prospectively enrolled 13 patients harboring a LGG of WHO Grade II. After assumed near total removal, a resection control was performed using navigated cioUS, navigated lioUS, and iMRI. We harvested 30 navigated biopsies from the resection cavity and compared the histopathological findings with the respective imaging results. Spearman's rho was calculated to test for significant correlations. Sensitivity and specificity as well as receiver operating characteristics (ROC) were calculated to assess test performance of each imaging modality. RESULTS: Imaging results of lioUS correlated significantly (p < 0.009) with iMRI. Both iMRI and lioUS correlated significantly with final histopathological diagnosis (p < 0.006, p < 0.014). cioUS did not correlate with other imaging findings or with final diagnosis. The highest sensitivity for residual tumor detection was found in iMRI (83 %), followed by lioUS (79 %). The sensitivity of cioUS was only 21 %. Specificity was highest in cioUS (100 %), whereas iMRI and lioUS both achieved 67 %. ROC curves showed fair results for iMRI and lioUS and a poor result for cioUS. CONCLUSIONS: Intraoperative resection control in LGGs using lioUS reaches a degree of accuracy close to iMRI. Test results of lioUS are superior to cioUS. cioUS often fails to discriminate solid tumors from "normal" brain tissue during resection control. Only in lesions <10 cc cioUS does show good accuracy.

Tumor detection with 5-aminolevulinic acid fluorescence and Gd-DTPA-enhanced intraoperative MRI at the border of contrast-enhancing lesions: a prospective study based on histopathological assessment.

OBJECT: High-grade gliomas (HGGs) and metastasis (MET) are the most common intracranial lesions in neurosurgical routine. Both of them show an invasive growth pattern extending into neural tissue beyond the margins of contrast enhancement on MRI. These "undetected" areas might be the origin of early tumor recurrence. The aim of the present study was to evaluate whether 5-aminolevulinic acid (5-ALA) fluorescence provides an additional benefit in detection of invasive tumor compared with intraoperative MRI (iMRI). METHODS: The authors prospectively enrolled 45 patients harboring contrast-enhancing lesions, in whom gross-total resection was intended. All patients had surgery in which iMRI and 5-ALA-guided resection were used following a specific protocol. First, a typical white light tumor resection was performed. Then, spatial location of residual fluorescence was marked. After that, an iMRI was performed and residual uptake of contrast was marked. Navigated biopsy samples were taken from all marked areas and from additional sites according to the surgeon's judgment. Cross tables and receiver operating characteristic curves were calculated, assessing performance of the imaging methods for tumor detection alone and for combined detection of infiltration zone and solid tumor (pathological tissue). Also, correlations of histopathological findings with imaging results were tested using Spearman rho. RESULTS: Thirty-four patients with HGGs and 11 with METs were enrolled. Three patients harboring a MET showed no 5-ALA enhancement and were excluded; 127 histopathological samples were harvested in the remaining patients. In HGG, sensitivity for tumor detection was significantly higher (p < 0.001) in 5-ALA (0.85) than in iMRI (0.41). Specificity was significantly lower (p < 0.001) in 5-ALA (0.43) than in iMRI (0.70). For detection of pathological tissue, 5-ALA significantly exceeded iMRI in specificity (0.80 vs 0.60) and sensitivity (0.91 vs 0.66) (p < 0.001). Imaging results of iMRI and 5-ALA did not correlate significantly; only 5-ALA showed a significant correlation with final histopathological diagnosis of the specimen and with typical histopathological features of HGGs. In METs, sensitivity and specificity for tumor detection were equal in 5-ALA and iMRI. Both techniques showed high values for sensitivity (0.75) and specificity (0.80). The odds ratio for detection of tumor tissue was 12 for both techniques. Concerning pathological tissue, no statistically significant difference was found either. Imaging results of iMRI and 5-ALA correlated significantly (p < 0.022), as with final histopathological diagnosis in METs. CONCLUSIONS: In METs, due to the rate of nonenhancing lesions, the authors found no additional benefit of 5-ALA compared with iMRI. In HGG, imaging results of 5-ALA and iMRI are significantly different at the border zone; 5-ALA has a higher sensitivity and a lower specificity for tumor detection than Gd-DTPA-enhanced iMRI. For detection of infiltrating tumor at the border of the resection cavity, 5-ALA is superior to Gd-DTPA-enhanced iMRI concerning both sensitivity and specificity. Thus, use of 5-ALA in addition to iMRI might be beneficial to maximize extent of resection. Clinical synergistic effects will be evaluated in a prospective randomized trial.

Explainable hybrid vision transformers and convolutional network for multimodal glioma segmentation in brain MRI.

Accurate localization of gliomas, the most common malignant primary brain cancer, and its different sub-region from multimodal magnetic resonance imaging (MRI) volumes are highly important for interventional procedures. Recently, deep learning models have been applied widely to assist automatic lesion segmentation tasks for neurosurgical interventions. However, these models are often complex and represented as "black box" models which limit their applicability in clinical practice. This article introduces new hybrid vision Transformers and convolutional neural networks for accurate and robust glioma segmentation in Brain MRI scans. Our proposed method, TransXAI, provides surgeon-understandable heatmaps to make the neural networks transparent. TransXAI employs a post-hoc explanation technique that provides visual interpretation after the brain tumor localization is made without any network architecture modifications or accuracy tradeoffs. Our experimental findings showed that TransXAI achieves competitive performance in extracting both local and global contexts in addition to generating explainable saliency maps to help understand the prediction of the deep network. Further, visualization maps are obtained to realize the flow of information in the internal layers of the encoder-decoder network and understand the contribution of MRI modalities in the final prediction. The explainability process could provide medical professionals with additional information about the tumor segmentation results and therefore aid in understanding how the deep learning model is capable of processing MRI data successfully. Thus, it enables the physicians' trust in such deep learning systems towards applying them clinically. To facilitate TransXAI model development and results reproducibility, we will share the source code and the pre-trained models after acceptance at https://github.com/razeineldin/TransXAI .

Comparison of navigated transcranial magnetic stimulation and functional magnetic resonance imaging for preoperative mapping in rolandic tumor surgery.

Navigated transcranial magnetic stimulation (nTMS) is a novel tool for preoperative functional mapping. It detects eloquent cortical areas directly, comparable to intraoperative direct cortical stimulation (DCS). The aim of this study was to evaluate the advantage of nTMS in comparison with functional magnetic resonance imaging (fMRI) in the clinical setting. Special focus was placed on accuracy of motor cortex localization in patients with rolandic lesions. Thirty consecutive patients were enrolled in the study. All patients received an fMRI and nTMS examination preoperatively. Feasibility of the technique and spatial resolution of upper and lower extremity cortical mapping were compared with fMRI. Consistency of preoperative mapping with intraoperative DCS was assessed via the neuronavigation system. nTMS was feasible in all 30 patients. fMRI was impossible in 7 out of 30 patients with special clinical conditions, pediatric patients, central vascular lesions, or compliance issues. The mean accuracy to localize motor cortex of nTMS was higher than in fMRI. In the subgroup of intrinsic tumors, nTMS produced statistically significant higher accuracy scores of the lower extremity localization than fMRI. fMRI failed to localize hand or leg areas in 6 out of 23 cases. Using nTMS, a preoperative localization of the central sulcus was possible in all patients. Verification of nTMS motor cortex localization with DCS was achieved in all cases. The fMRI localization of the hand area proved to be postcentral in one case. nTMS has fewer restrictions for preoperative functional mapping than fMRI and requires only a limited level of compliance. nTMS scores higher on the accuracy scale than fMRI. nTMS represents a highly valuable supplement for the preoperative functional planning in the clinical routine.

Intraoperative MRI-Guided Resection Is Not Superior to 5-Aminolevulinic Acid Guidance in Newly Diagnosed Glioblastoma: A Prospective Controlled Multicenter Clinical Trial.

PURPOSE: Prospective data suggested a superiority of intraoperative MRI (iMRI) over 5-aminolevulinic acid (5-ALA) for achieving complete resections of contrast enhancement in glioblastoma surgery. We investigated this hypothesis in a prospective clinical trial and correlated residual disease volumes with clinical outcome in newly diagnosed glioblastoma. METHODS: This is a prospective controlled multicenter parallel-group trial with two center-specific treatment arms (5-ALA and iMRI) and blinded evaluation. The primary end point was complete resection of contrast enhancement on early postoperative MRI. We assessed resectability and extent of resection by an independent blinded centralized review of preoperative and postoperative MRI with 1-mm slices. Secondary end points included progression-free survival (PFS) and overall survival (OS), patient-reported quality of life, and clinical parameters. RESULTS: We recruited 314 patients with newly diagnosed glioblastomas at 11 German centers. A total of 127 patients in the 5-ALA and 150 in the iMRI arm were analyzed in the as-treated analysis. Complete resections, defined as a residual tumor ≤0.175 cm³, were achieved in 90 patients (78%) in the 5-ALA and 115 (81%) in the iMRI arm (P = .79). Incision-suture times (P < .001) were significantly longer in the iMRI arm (316 v 215 [5-ALA] minutes). Median PFS and OS were comparable in both arms. The lack of any residual contrast enhancing tumor (0 cm³) was a significant favorable prognostic factor for PFS (P < .001) and OS (P = .048), especially in methylguanine-DNA-methyltransferase unmethylated tumors (P = .006). CONCLUSION: We could not confirm superiority of iMRI over 5-ALA for achieving complete resections. Neurosurgical interventions in newly diagnosed glioblastoma shall aim for safe complete resections with 0 cm³ contrast-enhancing residual disease, as any other residual tumor volume is a negative predictor for PFS and OS.

Explainability of deep neural networks for MRI analysis of brain tumors.

PURPOSE: Artificial intelligence (AI), in particular deep neural networks, has achieved remarkable results for medical image analysis in several applications. Yet the lack of explainability of deep neural models is considered the principal restriction before applying these methods in clinical practice. METHODS: In this study, we propose a NeuroXAI framework for explainable AI of deep learning networks to increase the trust of medical experts. NeuroXAI implements seven state-of-the-art explanation methods providing visualization maps to help make deep learning models transparent. RESULTS: NeuroXAI has been applied to two applications of the most widely investigated problems in brain imaging analysis, i.e., image classification and segmentation using magnetic resonance (MR) modality. Visual attention maps of multiple XAI methods have been generated and compared for both applications. Another experiment demonstrated that NeuroXAI can provide information flow visualization on internal layers of a segmentation CNN. CONCLUSION: Due to its open architecture, ease of implementation, and scalability to new XAI methods, NeuroXAI could be utilized to assist radiologists and medical professionals in the detection and diagnosis of brain tumors in the clinical routine of cancer patients. The code of NeuroXAI is publicly accessible at https://github.com/razeineldin/NeuroXAI .

Evaluation of a Navigated 3D Ultrasound Integration for Brain Tumor Surgery: First Results of an Ongoing Prospective Study.

The aim of the study was to assess the quality, accuracy and benefit of navigated 2D and 3D ultrasound for intra-axial tumor surgery in a prospective study. Patients intended for gross total resection were consecutively enrolled. Intraoperatively, a 2D and 3D iUS-based resection was performed. During surgery, the image quality, clinical benefit and navigation accuracy were recorded based on a standardized protocol using Likert's scales. A total of 16 consecutive patients were included. Mean ratings of image quality in 2D iUS were significantly higher than in 3D iUS (p < 0.001). There was no relevant decrease in rating during the surgery in 2D and 3D iUS (p > 0.46). The benefit was rated 2.2 in 2D iUS and 2.6 in 3D iUS (p = 0.08). The benefit remained stable in 2D, while there was a slight decrease in the benefit in 3D after complete tumor resection (p = 0.09). The accuracy was similar in both (mean 2.2 p = 0.88). Seven patients had a small tumor remnant in intraoperative MRT (mean 0.98 cm3) that was not appreciated with iUS. Crucially, 3D iUS allows for an accurate intraoperative update of imaging with slightly lower image quality than 2D iUS. Our preliminary data suggest that the benefit and accuracy of 2D and 3D iUS navigation do not undergo significant variations during tumor resection.

Role of interhemispheric connectivity in recovery from postoperative supplementary motor area syndrome in glioma patients.

OBJECTIVE: Surgical resection of gliomas involving the supplementary motor area (SMA) frequently results in SMA syndrome, a symptom complex characterized by transient akinesia and mutism. Because the factors influencing patient functional outcomes after surgery remain elusive, the authors investigated network-based predictors in a multicentric cohort of glioma patients. METHODS: The participants were 50 patients treated for glioma located in the SMA at one of the three centers participating in the study. Postoperative functional outcomes (motor deficits, mutism) and duration of symptoms were assessed during hospitalization. Long-term outcome was assessed 3 months after surgery. MRI-based lesion-symptom mapping was performed to estimate the severity of gray matter damage and white matter disconnection. RESULTS: The median duration of acute symptoms was 3 days (range 1-42 days). Long-term deficits involving fine motor movements and speech were found at follow-up in 27 patients (54%). Disconnection of the central callosal fibers was associated with prolonged acute symptoms (p < 0.05). Postoperative mutism was significantly related to disconnection severity of the left frontopontine tract, frontal aslant tract, cingulum, and corticostriatal tract (p < 0.05). Disconnection of midposterior callosal fibers and lesion loads within the left medial Brodmann area 4 were associated with long-term motor deficits (p < 0.05). CONCLUSIONS: This study provides evidence for the pathophysiology and predictive factors of postoperative SMA syndrome by demonstrating the relation of the disconnection of callosal fibers with prolonged symptom duration (central segment) and long-term motor deficits (midposterior segment). These data may be useful for presurgical risk assessment and adequate consultation for patients prior to undergoing resection of glioma located within the SMA region.

Resilience in Lower Grade Glioma Patients.

Current data show that resilience is an important factor in cancer patients' well-being. We aim to explore the resilience of patients with lower grade glioma (LGG) and the potentially influencing factors. We performed a cross-sectional assessment of adult patients with LGG who were enrolled in the LoG-Glio registry. By phone interview, we administered the following measures: Resilience Scale (RS-13), distress thermometer, Montreal Cognitive Assessment Test for visually impaired patients (MoCA-Blind), internalized stigmatization by brain tumor (ISBI), Eastern Cooperative Oncological Group performance status (ECOG), patients' perspective questionnaire (PPQ) and typical clinical parameters. We calculated correlations and multivariate regression models. Of 74 patients who were assessed, 38% of those showed a low level of resilience. Our results revealed significant correlations of resilience with distress (p < 0.001, −0.49), MOCA (p = 0.003, 0.342), ECOG (p < 0.001, −0.602), stigmatization (p < 0.001, −0.558), pain (p < 0.001, −0.524), and occupation (p = 0.007, 0.329). In multivariate analyses, resilience was negatively associated with elevated ECOG (p = 0.020, ß = −0.383) and stigmatization levels (p = 0.008, ß = −0.350). Occupation showed a tendency towards a significant association with resilience (p = 0.088, ß = −0.254). Overall, low resilience affected more than one third of our cohort. Low functional status is a specific risk factor for low resilience. The relevant influence of stigmatization on resilience is a novel finding for patients suffering from a glioma and should be routinely identified and targeted in clinical routine.