Prognostic validation of a new classification system for extent of resection in glioblastoma: a report of the RANO resect group

Influence of supratotal resection on overall survival and progression of tumor in gliomas grade 2 and 3: a systematic review and meta-analysis

BACKGROUND

Recurrence after resection is a major factor in poor prognosis for grade 2 and 3 gliomas. The effect of Supratotal Resection (STR) on recurrence timing remains debated. This meta-analysis examines overall survival (OS) and tumor progression in grade 2 and 3 gliomas after supratotal resection.

METHODS

Studies on patients with grade II and III gliomas who underwent supratotal resection were included, with comparisons to subtotal, partial, and total resections. The primary outcomes were overall survival (OS) and tumor progression, while secondary outcomes included return-to-work (RTW) rates, malignant transformations and cognitive impairments.

RESULTS

We included 954 patients from 8 studies, mean age was 39 (± 16) years. The mean OS for patients undergoing supratotal resection was 17.45 (95% CI: 3.39 to 89.74, p < 0.05) compared to TR. The OR for RTW in the STR group versus TR group was 0.12 (95% CI: 0.01 to 1.28, p = 0.08). Tumor progression OR was, no statistical significantly, 0.15 (95% CI: 0.00 to 38.00, p = 0.5), and the likelihood of malignancy was reduced 0.03 (95% CI: 0.01 to 0.18, p < 0.01) compared to the TR group. In the immediate pos-operatory, when comparing STR with TR, the OR of language impairment was 5.47 (95% CI: 2.73 to 10.97, p < 0.01) and cognitive impairment was 0.38 (95% CI: 0.17 to 0.58). During the follow-up, the OR of language impairment was 0.68 (95% CI: 0.25 to 1.81, p = 0.44) and cognitive impairment was 0.34 (95% CI: 0.03 to 3.61, p = 0.37) comparing STR with TR.

CONCLUSION

Patients with grade 2 and 3 gliomas undergoing supratotal resection showed significantly higher overall survival, fewer malignant transformations and language impairments in immediate pos-operatory. While there was a trend towards higher return-to-work rates, progression of tumor and better cognitive status during the follow-up, it was not statistically significant. Further studies are needed for definitive conclusions.

CLINICAL TRIAL NUMBER

Not applicable.

A Radiologist's Guide to IDH-Wildtype Glioblastoma for Efficient Communication With Clinicians: Part I-Essential Information on Preoperative and Immediate Postoperative Imaging

The paradigm of isocitrate dehydrogenase (IDH)-wildtype glioblastoma is rapidly evolving, reflecting clinical, pathological, and imaging advancements. Thus, it remains challenging for radiologists, even those who are dedicated to neuro-oncology imaging, to keep pace with this rapidly progressing field and provide useful and updated information to clinicians. Based on current knowledge, radiologists can play a significant role in managing patients with IDH-wildtype glioblastoma by providing accurate preoperative diagnosis as well as preoperative and postoperative treatment planning including accurate delineation of the residual tumor. Through active communication with clinicians, extending far beyond the confines of the radiology reading room, radiologists can impact clinical decision making. This Part 1 review provides an overview about the neuropathological diagnosis of glioblastoma to understand the past, present, and upcoming revisions of the World Health Organization classification. The imaging findings that are noteworthy for radiologists while communicating with clinicians on preoperative and immediate postoperative imaging of IDH-wildtype glioblastomas will be summarized.

Standardisation of the radiological definition of supramaximal resection in glioblastoma

Glioblastoma remains the most common and lethal primary malignant brain tumour, with high rates of recurrence and progression despite gross-total resection of the contrast-enhancing region based on T1-weighted MRI. There has been growing interest in exploring "supramaximal" resections that extend beyond contrast-enhancing borders, with initial retrospective data suggesting survival benefit, but there is currently no consensus definition. In this systematic review, we explore the evolution of supramaximal resection in glioblastoma, dissect the incongruencies in the literature regarding its definition, qualitatively appraise each definition and discuss the results of various studies that have explored its impacts on patient outcomes. MEDLINE, EMBASE, SCOPUS, Cochrane Registry of Clinical Trials and Pub-MED were systematically searched for studies of glioblastoma patients who had undergone supramaximal resection. After screening and applying eligibility criteria, 25 studies were included in the final review. Definitions were grouped according to radiological modality and visualisation adjuncts and included various extents of resection of hyperintensity visualised using T2-Fluid-Attenuated Inversion Recovery, various volumetric resections of the non-contrast enhancing region, removal of methionine-uptake areas on PET, complete removal of 5-aminolevulinic acid fluorescent tissue and lobectomies. Our systematic review identified a general trend suggesting a survival benefit from supramaximal resection compared to gross-total resection but, more importantly, demonstrated the limitations of these studies due to selection bias and substantial methodological heterogeneity. Ultimately, our findings demonstrate the need for an applicable, standardised and specific definition for supramaximal resection so that prospective studies can determine prognostically significant clinical data to guide the surgical management of glioblastoma.

Prognostic revalidation of RANO categories for extent of resection in glioblastoma: a reconstruction of individual patient data

BACKGROUND

The RANO classification for glioblastoma defines resection categories based on volumetric tumor assessments, aiming to standardize outcomes related to extent of resection (EOR). This study revalidates the prognostic impact of RANO classes by reconstructing individual patient data (IPD).

METHODS

A systematic review and meta-analysis were performed, including three studies comprising 580 glioblastoma patients. Included studies reported or allowed conversion to RANO classes for glioblastoma resection extent, with detailed OS data and numbers at risk. Overall survival (OS) data were extracted from Kaplan-Meier survival curves, and IPD were reconstructed using Digitizelt and the R package IPDfromKM. Survival analyses were conducted using Kaplan-Meier estimates and Cox regression models.

RESULTS

Median follow-up was 15.6 months (IQR: 10.1-28.8). Patients undergoing supramaximal resection (RANO class 1, n = 163) had the highest median OS (35.6 months; 95% CI: 30.9-40.4), significantly outperforming non-class 1 resections (median OS: 13.9 months; 95% CI: 13.0-14.7; p < 0.001). Subgroup analysis revealed superior OS for class 2a (19.0 months) over class 2b (14.1 months; p < 0.001), while class 3 and 4 resections demonstrated progressively poorer outcomes. Hazard ratios consistently favored class 1 versus all other classes (HR: 0.28; 95% CI: 0.23-0.37).

CONCLUSIONS

Supramaximal (class 1) resection provides a significant survival benefit in glioblastoma, underscoring its critical role in surgical management. The RANO classification stratifies resection outcomes effectively, supporting its use as a prognostic tool. These findings advocate for resection strategies targeting maximal tumor removal.

The ATLAS/NOA-29 study protocol: a phase III randomized controlled trial of anterior temporal lobectomy versus gross-total resection in newly-diagnosed temporal lobe glioblastoma

BACKGROUND

The discovery of cellular tumor networks in glioblastoma, with routes of malignant communication extending far beyond the detectable tumor margins, has highlighted the potential of supramarginal resection strategies. Retrospective data suggest that these approaches may improve long-term disease control. However, their application is limited by the proximity of critical brain regions and vasculature, posing challenges for validation in randomized trials. Anterior temporal lobectomy (ATL) is a standardized surgical procedure commonly performed in patients with pharmacoresistant temporal lobe epilepsy. Translating the ATL approach from epilepsy surgery to the neuro-oncological field may provide a model for investigating supramarginal resection in glioblastomas located in the anterior temporal lobe.

METHODS

The ATLAS/NOA-29 trial is a prospective, multicenter, multinational, phase III randomized controlled trial designed to compare ATL with standard gross-total resection (GTR) in patients with newly-diagnosed anterior temporal lobe glioblastoma. The primary endpoint is overall survival (OS), with superiority defined by significant improvements in OS and non-inferiority in the co-primary endpoint, quality of life (QoL; "global health" domain of the European organization for research and treatment of cancer (EORTC) QLQ-C30 questionnaire). Secondary endpoints include progression-free survival (PFS), seizure outcomes, neurocognitive performance, and the longitudinal assessment of six selected domains from the EORTC QLQ-C30 and BN20 questionnaires. Randomization will be performed intraoperatively upon receipt of the fresh frozen section result. A total of 178 patients will be randomized in a 1:1 ratio over a 3-year recruitment period and followed-up for a minimum of 3 years. The trial will be supervised by a Data Safety Monitoring Board, with an interim safety analysis planned after the recruitment of the 57th patient to assess potential differences in modified Rankin Scale (mRS) scores between the treatment arms 6 months after resection. Assuming a median improvement in OS from 17 to 27.5 months, the trial is powered at > 80% to detect OS differences with a two-sided log-rank test at a 5% significance level.

DISCUSSION

The ATLAS/NOA-29 trial aims to determine whether ATL provides superior outcomes at equal patients' Qol compared to GTR in anterior temporal lobe glioblastoma, potentially establishing ATL as the surgical approach of choice for isolated temporal glioblastoma and redefining the standard of care for this patient population.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS00035314), registered on October 18, 2024.

Leptomeningeal metastases at recurrence in IDH-wildtype glioblastomas: incidence, risk factors, and prognosis based on postcontrast FLAIR imaging

OBJECTIVES

To comprehensively investigate the incidence, risk factors, and prognosis of leptomeningeal metastases (LM) diagnosed at recurrence in IDH-wildtype glioblastoma patients.

MATERIALS AND METHODS

A total of 734 IDH-wildtype glioblastoma patients were enrolled between 2005 and 2022. LM at recurrence was diagnosed with MRI including postcontrast FLAIR. Logistic analysis for development of LM at recurrence was performed with clinical, molecular, imaging (including tumor volume and distance to subventricular zone via automatic segmentation), and surgical data including extent of resection and ventricular entry. The overall survival (OS) was compared between patients with and without LM at recurrence.

RESULTS

The incidence of LM at recurrence based on postcontrast FLAIR was 10.8% (79 patients). On multivariable analysis, younger age at diagnosis (odds ratio (OR) = 0.98, p = 0.011) and ventricular entry (OR = 3.15, p < 0.001) were independent predictors of LM at recurrence. However, patients with LM at recurrence showed no significant difference in OS from patients without LM (log-rank test; p = 0.461), with median OS of 18.0 (95% confidence interval (CI) 16.2-19.8) and 18.5 (95% CI 16.4-20.7) months in patients with and without LM at recurrence, respectively.

CONCLUSION

The incidence of LM at recurrence is relatively high in IDH-wildtype glioblastoma patients. Younger age and ventricular entry during surgery warrant imaging surveillance for LM at recurrence. As LM at recurrence showed no significant OS compromise and larger extent of resection (EOR) is associated with survival benefits, ventricular entry during maximal safe resection may be acceptable.

KEY POINTS

Question The incidence, risk factors, and prognosis of leptomeningeal metastases (LM) diagnosed at recurrence in IDH-wildtype glioblastoma patients are currently unknown. Findings LM at recurrence occurred in 10.8% of cases, with younger age and ventricular entry as risk factors, but no significant difference in survival outcomes between groups. Clinical relevance The incidence, risk factors, and prognosis of LM at recurrence were investigated in IDH-wildtype glioblastoma patients with postcontrast FLAIR. Younger age and ventricular entry warrant surveillance of LM at recurrence, while the overall survival is not as discouraging as expected.

Preoperative Peripheral Blood Serotonin and Kynurenine Levels Are Associated With Oncological Outcomes in Glioblastoma IDH-wt Patients

Background

In recent years, there has been a growing interest in exploring the potential contribution of tryptophan (TRP) metabolism via the kynurenine (KP) and serotonin (SP) pathways in Glioblastoma (GBM) biology. This study aims to address the association between pre-operative peripheral blood levels of TRP, kynurenine (KYN), 5-hydroxy-tryptophan (5-HTP), and serotonin (5-HT) and relevant oncological outcomes in GBM IDH-wt patients.

Methods

This is a single-center, retrospective clinical study. Serum from 62 adult patients undergoing maximal safe resection of newly diagnosed glioblastoma WHO-grade 4 IDH-wt (GBM) and n = 27 healthy controls were analyzed. The variables of interest were dichotomized via maximally selected rank statistics. Kaplan Meier and Cox multivariate regression analysis were conducted to explore the single contributions of these parameters in building a predictive model of overall survival (OS) and progression-free survival (PFS) in these patients.

Results

The mean baseline serum levels of 5-HT, KYN, and 5-HTP were significantly lower in GBM when compared to n = 27 healthy individuals (P < .001). Patients with 5-HT <78 ng/mL had a median OS of 14.4 months compared to 22.5 months in patients with increased levels (P = .01). Shorter OS was observed in patients with KYN <18 ng/mL (9.8 vs 17.5 months, P = .002), KYN/TRP <2.55 (11.4 vs 17.1, P = .002), 5-HTP/TRP <0.89 (11.5 vs 17.6 months, P = .02), and 5-HT/TRP <5.78 (13.4 vs 19.1 months, P = .002) compared to patients with high levels. Shorter PFS in patients with 5-HT <78 ng/mL (P = .04), KYN <18 ng/mL (P = .02), 5-HT/TRP <5.78 (P = .001), KYN/TRP <2.55 (P = .005). Reduced KYN, 5-HTP, and 5-HT were independent predictors of poor OS.

Conclusions

This study highlights an intriguing association between the degradation of TRP along the KP and SP and median survival times in GBM. Decreased KYN, 5-HTP, and 5-HT levels were associated with shorter OS.

Outcomes of awake surgery for recurrent glioblastoma: A single-institution retrospective analysis

BACKGROUND

Awake surgery facilitates maximal safe resection of brain tissue in cases of glioma, but its effectiveness for recurrent glioblastoma (GBM) remains unestablished. In this study, we investigate the safety, success rate of mapping, and surgical outcomes of awake surgery for recurrent GBM.

METHODS

This study included glioma cases that underwent awake surgery at our hospital between March 2010 and February 2023 and met the following criteria: (1) cases with a pathologic diagnosis of glioblastoma or astrocytoma, isocitrate dehydrogenase-mutant, WHO grade 4 at recurrence, and (2) cases in which this was the second surgery in the course of treatment. We retrospectively analyzed the clinical features, mapping response, resection rate, postoperative complications, overall survival (OS), and progression-free survival (PFS).

RESULTS

Forty-one cases were analyzed. The median age was 47 years, and 24 patients (58.5 %) were male. Awake mapping was successfully completed in 35 cases (85.4 %). A positive response to mapping was observed in 20 cases (48.8 %), which limited resection in 15 cases (36.6 %). The extent of resection was gross total resection in 20 cases (48.8 %), subtotal resection in 11 cases (26.8 %), partial resection in 8 cases (19.5 %), and biopsy in 2 cases (4.9 %). Acute-phase neurological deficits developed in 10 cases (24.4 %), but sequelae or symptom exacerbations were observed in 2 cases (4.9 %). The median post-recurrence OS and PFS were 18.7 months and 7.2 months, respectively.

CONCLUSIONS

Awake mapping for recurrent GBM demonstrated a low complication rate and facilitated tumor resection without exacerbating neurological symptoms. Awake surgery for recurrent GBM may contribute to prolonged survival.

Safety and Efficacy in the Transcortical and Transsylvian Approach in Insular High-Grade Gliomas: A Comparative Series of 58 Patients

Gliomas within the insular region represent one of the most challenging problems in neurosurgical oncology. There are two main surgical approaches to address the complex vascular network and functional areas around the insula: the transsylvian approach and the transcortical approach. In the literature, there is not a clear consensus on the best approach in terms of safety and efficacy. The purpose of this study is to evaluate the effectiveness of these approaches and to analyze prognostic factors on the natural history of insular gliomas. Patients with newly diagnosed high-grade insular gliomas who underwent surgery between January 2019 and June 2024 were analyzed. The series was analyzed according to the classification of Berger-Sanai and Yaşargil. The Karnofsky performance score (KPS), extent of resection (EOR), progression-free survival (PFS), and overall survival (OS) were considered the outcome measures. A total of 58 primary high-grade insular glioma patients were enrolled in this study. The IDH mutation was found in 13/58 (22.4%); specifically, 3/13 (23.1%) were grade 4, and 10/13 (76.9%) were grade 3. Furthermore, 40/58 patients (69%) underwent gross total resection (GTR), 15 patients (26%) subtotal resection, and 3 patients (5%) partial resection. Middle cerebral artery encasement negatively affected the OS. GTR, radiotherapy, KPS, and autonomous deambulation at a month after surgery positively affected the OS. The surgical approach used was transsylvian and transcortical in 11 and 47 cases, respectively. The comparison between the two different approaches did not display differences in terms of neurological deficits and OS (p > 0.05). The transcortical approach was related to the greater achievement of GTR (p = 0.031). According to the Berger-Sanai classification, the transcortical approach has higher EOR and postoperative KPS when the lesion is in zone III-IV (p = 0.029). Greater resection of insular gliomas can be achieved with an acceptable morbidity profile and is predictive of improved OS. Both the transsylvian and transcortical corridors to the insula are associated with low morbidity profiles. The transcortical approach with intraoperative mapping is more favorable for achieving greater EOR, particularly in gliomas within the inferior border of the Sylvian fissure.

Quantitative assessment of residual tumor is a strong and independent predictor of survival in methylated glioblastoma following radiochemotherapy with lomustine/temozolomide

BACKGROUND

Maximum tumor resection improves overall survival (OS) in patients with glioblastoma. The extent of resection (EOR) is historically dichotomized. The response assessment in neuro-oncology (RANO) resects group recently proposed criteria for volumetry-based EOR assessment in patients that were treated according to Stupp´s protocol. The purpose of this study was (1) to investigate the prognostic value of EOR in patients receiving combined chemotherapy with lomustine (CCNU)/temozolomide (TMZ), and (2) to analyze the prognostic performance of binary EOR assessment compared to volumetric assessment.

METHODS

Seventy-eight patients with newly diagnosed MGMT-methylated GBM undergoing tumor resection followed by radiochemotherapy with CCNU/TMZ were included in this study. Residual contrast-enhancing (CE) tumor volume after the first resection was measured and its influence on OS and progression-free survival was analyzed using uni- and multivariable Cox regression analysis as well as two-sided log-rank test. Patients were divided into residual tumor volume (RTV) ≤1 cm³, >1-≤5 cm³, and >5 cm³ following the proposed criteria of the RANO resect group.

RESULTS

Prolonged OS was associated with age <60 years, low RTV, and gross total resection. RTV had a superior prognostic value compared to binary EOR assessment. Patients with total or near total resection of CE tumor (≤ 1 cm³ RTV) showed prolonged OS (median 54.4 months, 95% CI: 46.94-not reached), with a 5-year survival rate of 49%.

CONCLUSIONS

Low RTV is associated with increased survival in glioblastoma patients undergoing radiochemotherapy with CCNU/TMZ. This study demonstrates the applicability of the recently proposed RANO resect criteria in this subgroup of patients.

Sonodynamic therapy with a single neoadjuvant, diffuse delivery of low-intensity ultrasound with 5-ALA in treatment naïve glioblastoma results in tumor-specific cytotoxic edema and increased apoptosis

PURPOSE

Sonodynamic therapy, which combines a tumor cell-selective sonosensitizer with ultrasound, is gaining attention as a promising new treatment approach for glioblastoma. The objective of this case study is to report on the first applications of 5-aminolevulinic acid (5-ALA) in combination with low-intensity, non-targeted ultrasound as neo-adjuvant treatment in therapy naïve glioblastoma.

METHODS

Three patients with therapy naïve newly diagnosed glioblastoma were treated once before cytoreductive surgery with 5-ALA in combination with hemispheric, low-intensity, non-targeted ultrasound, assuming cell death to be triggered by non-ablative activation of 5-ALA-induced, tumor selective porphyrins.

RESULTS

No adverse effects were noted. Post-procedural MRI indicated a decrease in apparent diffusion coefficient values in tumors, suggesting cytotoxic effects. Relative cerebral blood volumes and leakage were increased for two patients with available perfusion imaging. Tissue obtained during surgery suggested increased cleaved-caspase III expression, a marker of apoptosis.

CONCLUSION

We saw an immediate marked imaging response indicating cytotoxic edema and indications of a histopathology response from just a single treatment. Correlation to clinical outcomes and extension of overall survival remains to be seen. A Phase 1 safety study has been submitted for regulatory approval.

Unraveling the heterogeneity of WHO grade 4 gliomas: insights from clinical, imaging, and molecular characterization

PURPOSE

The 2021 WHO classification of central nervous system tumors introduced molecular criteria to stratify Grade 4 gliomas, which remain heterogeneous. This study aims to elucidate the clinical, radiological, and molecular characteristics of WHO Grade 4 gliomas, focusing on their prognostic implications and the development of a predictive model for astrocytoma IDH-mutant WHO Grade 4 (A4).

METHODS

A retrospective cohort of 223 patients from Beijing Tiantan Hospital was analyzed. Clinical, radiological, and histopathological data were combined with molecular profiling, focusing on IDH mutations, TERT promoter mutations, and MGMT methylation. A predictive model was developed using LASSO regression to distinguish A4 from glioblastomas and validated with an external dataset from UCSF.

RESULTS

The cohort included 201 glioblastomas (90.1%) and 22 A4 cases (9.9%). A4 tumors were associated with younger age, higher MGMT promoter methylation, lower rates of TERT mutations, and distinct radiological features, such as cortical non-enhancing tumor infiltration (CnCE). Patients with A4 demonstrated significantly better survival outcomes compared to glioblastoma patients (p < 0.001). The predictive model for A4, incorporating age, tumor margin, and CnCE, achieved an AUC of 0.890 in the training set and 0.951 in the validation set.

CONCLUSION

Integrating molecular and clinical criteria improves prognostication in Grade 4 gliomas. The predictive model developed in this study effectively identifies A4 tumors, facilitating more personalized therapeutic strategies.

TTF-1 negativity in synchronous M1b/M1c wildtype lung adenocarcinoma brain metastases predicts worse survival with increased risk of intracranial progression

BACKGROUND

Thyroid Transcription Factor-1 (TTF-1) expression in lung adenocarcinoma (LUAD) has been studied for its prognostic value in early-stage and metastatic disease. Its role in brain metastasis remains unexplored. This study investigates the predictive value and association of TTF-1 status with clinicopathological variables in patients with synchronous LUAD brain metastases.

MATERIAL AND METHODS

In this bicentric retrospective study, 245 patients with newly diagnosed, treatment-naïve brain metastasis undergoing resection were included. Patient data were retrieved from electronic records. Outcomes included overall and progression-free survival. Statistical analysis included Kaplan-Meier estimates and Cox proportional hazards regression.

RESULTS

Mean Ki67 index in TTF-1 negative patients was 43% [95% CI 38-48%] compared to 32% [95% CI 29-35%] in TTF-1 positive (TTF-1 +) patients (p < 0.001). Tumor volume was significantly larger in TTF-1 negative (TTF-1-) patients (mean volume 24 mL [95% CI 18-31 mL]) vs. 15 mL [95% CI 12-17 mL] in TTF-1 + patients (padjust = 0.003). Perifocal edema was smaller in TTF-1- patients (mean volume: 58 mL [95% CI 45-70 mL]) vs. 84 mL [95% CI 73-94 mL] in TTF-1 + patients (padjust = 0.077). Tumor and edema volume did not correlate. TTF-1- patients showed worse overall, intracranial, and extracranial progression-free survival. In a multivariable Cox model, positive TTF-1 status was independently associated with improved outcomes. Negative TTF-1 status was associated with increased hazard for intracranial disease progression compared to extracranial progression.

CONCLUSION

In synchronous LUAD brain metastases, TTF-1 negativity reflects an aggressive phenotype with larger proliferation capacity and tumor volume. Future research should explore the underlying cellular and molecular alterations of this phenotype.

Implications of molecular classifications in glioma surgery

PURPOSE

The incorporation of molecular markers into neuro-oncology has transformed our understanding of adult diffuse gliomas. While surgical resection is the mainstay of treatment for many patients with gliomas, surgical management strategies warrant re-exploration in the context of characteristic molecular profiles.

METHODS

We reviewed the neurosurgical and neuro-oncological literature for studies investigating surgery in molecularly defined cohorts of adult diffuse gliomas.

RESULTS

We discuss key molecular markers associated with the three subtypes of adult diffuse glioma: glioblastoma IDH-wildtype, astrocytoma IDH-mutant, and oligodendroglioma IDH-mutant and 1p/19q codeleted. We additionally discuss surgical strategies and extent of resection in these tumors, framing them in the context of key molecular alterations. Finally, we briefly discuss the practical utility of molecular markers in guiding surgical decision making.

CONCLUSION

Molecular markers in gliomas are of growing relevance to surgical intervention. Advancements in preoperative and intraoperative molecular diagnostics will increase the utility of molecular biomarkers in informing surgical decision-making for patients with gliomas.

Progression of the Residual Lesion in Cavernous Sinus Extra-Axial Cavernous Hemangioma After Surgery

Our study aimed to investigate the factors associated with residual cavernous sinus extra-axial cavernous hemangiomas (ECHs) progression after surgery. This retrospective study consecutively included patients of cavernous sinus ECHs with incomplete lesion resection from February 2012 to January 2024. The progression of the lesions was defined as new lesions or a growth of residual lesion (≥ 10% increase in volume). Cox regression analysis was used to determine factors associated with residual lesion progression. Kaplan-Meier analysis was conducted to estimate the cumulative incidence of residual lesion progression. Sixty patients were included in this study. During the follow-up, there were 31 (51.7%) residual lesions underwent progression, whereas 29 (48.3%) patients were nonprogressive. Multivariate Cox analysis showed that the homogeneous enhancement lesion was correlated with the residual lesion progression (HR, 8.17 [95% CI, 1.03-64.58]; p = 0.046). Kaplan-Meier survival analysis indicated that the rate of homogeneous enhancement lesion progression (3.7 per 10 person-years) was significantly higher than that of the heterogeneous enhancement group (0.5 per 10 person-years; p = 0.019). Fourteen of the 31 patients with lesion progression underwent radiotherapy, and all of them experienced control over the progression of their lesions. This study found that end-of-treatment residual lesions are not rare in patients with cavernous sinus ECHs and the MRI feature is helpful to predict the progression of residual lesions.

Response Assessment in Long-Term Glioblastoma Survivors Using a Multiparametric MRI-Based Prediction Model

Purpose: Early treatment response assessments are crucial, and the results are known to better correlate with prognosis and survival outcomes. The present study was conducted to differentiate true progression (TP) from pseudoprogression (PsP) in long-term-surviving glioblastoma patients using our previously established multiparametric MRI-based predictive model, as well as to identify clinical factors impacting survival outcomes in these patients. Methods: We report six patients with glioblastoma that had an overall survival longer than 5 years. When tumor specimens were available from second-stage surgery, histopathological analyses were used to classify between TP (>25% characteristics of malignant neoplasms; n = 2) and PsP (<25% characteristics of malignant neoplasms; n = 2). In the absence of histopathology, modified RANO criteria were assessed to determine the presence of TP (n = 1) or PsP (n = 1). The predictive probabilities (PPs) of tumor progression were measured from contrast-enhancing regions of neoplasms using a multiparametric MRI-based prediction model. Subsequently, these PP values were used to define each lesion as TP (PP ≥ 50%) or PsP (PP < 50%). Additionally, detailed clinical information was collected. Results: Our predictive model correctly identified all patients with TP (n = 3) and PsP (n = 3) cases, reflecting a significant concordance between histopathology/modified RANO criteria and PP values. The overall survival varied from 5.1 to 12.3 years. Five of the six glioblastoma patients were MGMT promoter methylated. All patients were female, with a median age of 56 years. Moreover, all six patients had a good functional status (KPS ≥ 70), underwent near-total/complete resection, and received alternative therapies. Conclusions: Multiparametric MRI can aid in assessing treatment response in long-term-surviving glioblastoma patients.

Characterizing and targeting glioblastoma neuron-tumor networks with retrograde tracing

Glioblastomas are invasive brain tumors with high therapeutic resistance. Neuron-to-glioma synapses have been shown to promote glioblastoma progression. However, a characterization of tumor-connected neurons has been hampered by a lack of technologies. Here, we adapted retrograde tracing using rabies viruses to investigate and manipulate neuron-tumor networks. Glioblastoma rapidly integrated into neural circuits across the brain, engaging in widespread functional communication, with cholinergic neurons driving glioblastoma invasion. We uncovered patient-specific and tumor-cell-state-dependent differences in synaptogenic gene expression associated with neuron-tumor connectivity and subsequent invasiveness. Importantly, radiotherapy enhanced neuron-tumor connectivity by increased neuronal activity. In turn, simultaneous neuronal activity inhibition and radiotherapy showed increased therapeutic effects, indicative of a role for neuron-to-glioma synapses in contributing to therapeutic resistance. Lastly, rabies-mediated genetic ablation of tumor-connected neurons halted glioblastoma progression, offering a viral strategy to tackle glioblastoma. Together, this study provides a framework to comprehensively characterize neuron-tumor networks and target glioblastoma.

Prognostic and clinical significance of contrast enhancement in WHO grade 2 oligodendrogliomas

PURPOSE

To investigate the prognostic significance of contrast enhancement (CE) in grade 2 oligodendroglioma (ODG) and explore its clinical implications.

METHODS

Patients diagnosed with isocitrate dehydrogenase (IDH)-mutant, 1p/19q co-deleted ODG between 2009 and 2016 were retrospectively enrolled from a single institution. The presence of CE was identified on preoperative MRIs, and clinical, radiologic, and histopathological data that was extracted. Subgroup analyses were performed to evaluate differences in these factors and prognoses. Cox proportional hazards regression analyses were used to identify prognostic factors.

RESULTS

258 patients with pathologically confirmed WHO grade 2 ODGs were included. The entire cohort was divided into the CE group (n = 133, 51.6%) and the non-CE group (n = 125, 48.4%). Patients with CE on preoperative MRI showed significantly worse progression-free survival (PFS) compared to those without CE (median PFS: 133 months vs. not reached; p < 0.001) and overall survival (OS) (mean OS: 151 months vs. 155 months; median OS: not reached; p = 0.021). Furthermore, CE presence was identified as an independent prognostic factor in the Cox multivariate analysis. Patients within the CE cohort were further categorized into strong and weak CE subgroups based on the pattern of CE. Logistic regression analysis revealed that non-frontal lobe location (OR = 3.287, p = 0.042), higher Ki-67 index (OR = 3.782, p = 0.027), and 1q/19p co-polysomy (OR = 9.658, p = 0.001) were significantly associated with a higher incidence of the strong CE in ODGs. Furthermore, ODG patients in the strong CE subgroup demonstrated the poorest survival outcomes.

CONCLUSION

CE on preoperative MRI is a valuable prognostic marker in the grade 2 ODGs, with strong CE indicating the poorest survival outcomes. Further validation through larger cohort studies will help confirm these findings and refine survival stratification in clinical practice.

68Ga-NOTA-RM26 PET/CT in the evaluation of glioma: a pilot prospective study

BACKGROUND

Gliomas are the most common malignant primary tumors of the central nervous system. There is an urgent need for new convenient, targeted and specific imaging agents for gliomas. This study aimed to firstly evaluate the feasibility of 68Ga-NOTA-RM26 PET/CT imaging in glioma and analyze the relationship between the imaging characteristics and glioma grade, classification and molecular alterations.

RESULTS

Twenty-two patients were confirmed as glioma by surgery or biopsy. All patients exhibited 68Ga-NOTA-RM26 uptake. SUVmax was chosen as the imaging marker for analysis. For all glioma patients, there were significant differences between grades (P = 0.047). For primary gliomas, SUVmax had good discrimination for both tumor classifications (P = 0.045) and grades (P = 0.03). There was a positive correlation (P < 0.01) between GRPR expression level and SUVmax. P53 mutations caused significant differences in SUVmax (P = 0.03).

CONCLUSIONS

This study is the first application of 68Ga-NOTA-RM26 in glioma patients and confirmed the safety and efficacy in glioma patients. 68Ga-NOTA-RM26 PET/CT has potential value in tumor grade, classification, and molecular alterations.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT06412952. Registered 26 April 2024, https://clinicaltrials.gov/study/NCT06412952.

Longitudinal multimodal profiling of IDH-wildtype glioblastoma reveals the molecular evolution and cellular phenotypes underlying prognostically different treatment responses

BACKGROUND

Despite recent advances in the biology of IDH-wildtype glioblastoma, it remains a devastating disease with median survival of less than 2 years. However, the molecular underpinnings of the heterogeneous response to the current standard-of-care treatment regimen consisting of maximal safe resection, adjuvant radiation, and chemotherapy with temozolomide remain unknown.

METHODS

Comprehensive histopathologic, genomic, and epigenomic evaluation of paired initial and recurrent glioblastoma specimens from 106 patients was performed to investigate the molecular evolution and cellular phenotypes underlying differential treatment responses.

RESULTS

While TERT promoter mutation and CDKN2A homozygous deletion were early events during gliomagenesis shared by initial and recurrent tumors, most other recurrent genetic alterations (eg, EGFR, PTEN, and NF1) were commonly private to initial or recurrent tumors indicating acquisition later during clonal evolution. Furthermore, glioblastomas exhibited heterogeneous epigenomic evolution with subsets becoming more globally hypermethylated, hypomethylated, or remaining stable. Glioblastoma that underwent sarcomatous transformation had shorter interval to recurrence and were significantly enriched in NF1, TP53, and RB1 alterations and the mesenchymal epigenetic class. Patients who developed somatic hypermutation following temozolomide treatment had significantly longer interval to disease recurrence and prolonged overall survival, and increased methylation at 4 specific CpG sites in the promoter region of MGMT was significantly associated with this development of hypermutation. Finally, an epigenomic evolution signature incorporating change in DNA methylation levels across 347 critical CpG sites was developed that significantly correlated with clinical outcomes.

CONCLUSIONS

Glioblastoma undergoes heterogeneous genetic, epigenetic, and cellular evolution that underlies prognostically different treatment responses.

Mapping tumor habitats in isocitrate dehydrogenase -wild type glioblastoma: Integrating MRI, pathologic, and RNA data from the Ivy Glioblastoma Atlas Project

BACKGROUND

The goal of the study was to spatially validate intratumoral subregions (tumor habitat) using physiologic magnetic resonance imaging (MRI) on the pathology of the isocitrate dehydrogenase (IDH)-wild-type whole-glioblastoma sample.

METHODS

Data from 20 patients (168 slides) were obtained from the Ivy Glioblastoma Atlas Project. On MRI, tumor habitats were defined using voxel-wise clustering of the apparent diffusion coefficient and cerebral blood volume maps for contrast-enhancing lesions (CEL) and non-enhancing lesions (NEL). On pathology slides, normalized areas of leading-edge, infiltrating tumor (IT), cellular tumor (CT), hypervascular lesion (CThypervascular), and perinecrotic lesion (CTperinecrotic) were obtained. Gross specimen was coregistered on MRI and correlation between pathology-MRI habitats was calculated. RNA sequencing of 67 samples was assessed using 4 Neftel subtypes and further correlated with pathology.

RESULTS

Six tumor habitats were identified: hypervascular, hypovascular cellular, and hypovascular hypocellular habitats for CEL and NEL. CT was correlated with hypovascular cellular habitat in CEL (r = 0.238, P = .005). IT was correlated with hypovascular cellular habitat in NEL (r = 0.294, P = .017). CThypervascular was correlated with hypervascular habitat in NEL (r = 0.195, P = .023). CTperinecrotic was correlated with imaging necrosis (r = 0.199, P = .005). Astrocyte-like subtypes were correlated with IT (r = 0.256, P < .001), while mesenchymal-like subtypes were correlated with CTperinecrotic area (r = 0.246, P < .001).

CONCLUSIONS

Pathologically matched tumor subregions were CT with hypovascular cellular habitat in CEL and infiltrative tumor with hypovascular cellular habitat in NEL. Identification of the most aggressive, as well as infiltrative tumor portion, can be achieved using noninvasive MRI tumor habitats.

Measurable disease as baseline criterion for response assessment in glioblastoma: A comparison of PET -based (PET RANO 1.0) and MRI-based (RANO) assessments

BACKGROUND

Recently, criteria based on amino acid positron emission tomography (PET) have been proposed for response assessment in diffuse gliomas (PET RANO 1.0). In this study, we compare the prevalence of measurable disease according to PET RANO 1.0 with magnetic resonance imaging (MRI)-based Response Assessment in Neuro-Oncology (RANO) criteria in glioblastoma.

METHODS

We retrospectively identified patients with newly diagnosed IDH-wild-type glioblastoma who underwent [18F] Fluoroethyltyrosine (FET) PET and MRI after resection or biopsy and before radio-/radiochemotherapy. Two independent investigators analyzed measurable disease according to PET RANO 1.0 or MRI-RANO criteria. Additionally, lesion size, congruency patterns, and uptake intensity on [18F]FET PET images were assessed.

RESULTS

We evaluated 125 patients including 49 cases after primary resection and 76 cases after biopsy. Using PET criteria, 113 out of 125 patients (90.4%) had measurable disease, with a median PET-positive volume of 15.34 cm3 (8.83-38.03). With MRI, a significantly lower proportion of patients had measurable disease (57/125, 45.6%; P < .001) with a median sum of maximum cross-sectional diameters of 35.65 mm (26.18-45.98). None of the 12 patients without measurable disease on PET had measurable disease on MRI. Contrariwise, 56/68 patients (82.4%) without measurable disease on MRI exhibited measurable disease on PET. Clinical performance status correlated significantly with PET-positive volume and MRI-based sum of diameters (P < .0059, P < .0087, respectively).

CONCLUSIONS

[18F]FET PET identifies a higher number of patients with measurable disease compared to conventional MRI in newly diagnosed glioblastoma. PET-based assessment may serve as a novel baseline parameter for evaluating residual tumor burden and improving patient stratification in glioblastoma studies. Further validation in prospective trials is warranted.

Factors involved in maintaining Karnofsky Performance Status (≥ 50%) in glioblastoma, IDH-wildtype patients treated with temozolomide and radiotherapy

Karnofsky Performance Status (KPS) is a widely used scale to assess performance status. KPS ≥ 50% implies that patients can live at home. Therefore, maintaining KPS ≥ 50% is important to improve the quality of life of patients with glioblastoma, whose median survival is less than 2 years. This study aimed to identify the factors associated with survival time with maintenance of KPS ≥ 50% (survival with KPS ≥ 50%) in patients with glioblastoma, IDH-wildtype. Ninety-eight patients with glioblastomas, IDH-wildtype, who were treated with concomitant radiotherapy (RT) and temozolomide (TMZ) followed by maintenance TMZ therapy, and whose KPS at the start of RT was ≥ 50%, were included. The median survival with KPS ≥ 50% was 13.3 months. In univariate analysis, preoperative KPS (≥ 80%), KPS at the start of RT (≥ 80%), residual tumor size (< 2 cm3), methylated MGMT promotor, and implantation of BCNU wafer were associated with survival with KPS ≥ 50%. In multivariate analysis, KPS at the start of RT (≥ 80%), methylated MGMT promotor, and residual tumor size (< 2 cm3) were significantly associated with increased survival with KPS ≥ 50%. A strategy of maximum possible tumor resection without compromising KPS is desirable to prolong the survival time with KPS ≥ 50%.

Glioblastoma: Clinical Presentation, Multidisciplinary Management, and Long-Term Outcomes

Glioblastoma, the most common and aggressive primary brain tumor in adults, presents a formidable challenge due to its rapid progression, treatment resistance, and poor survival outcomes. Standard care typically involves maximal safe surgical resection, followed by fractionated external beam radiation therapy and concurrent temozolomide chemotherapy. Despite these interventions, median survival remains approximately 12-15 months, with a five-year survival rate below 10%. Prognosis is influenced by factors such as patient age, molecular characteristics, and the extent of resection. Patients with IDH-mutant tumors or methylated MGMT promoters generally have improved survival, while recurrent glioblastoma is associated with a median survival of only six months, as therapies in these cases are often palliative. Innovative treatments, including TTFields, add incremental survival benefits, extending median survival to around 20.9 months for eligible patients. Symptom management-addressing seizures, headaches, and neurological deficits-alongside psychological support for patients and caregivers is essential to enhance quality of life. Emerging targeted therapies and immunotherapies, though still limited in efficacy, show promise as part of an evolving treatment landscape. Continued research and clinical trials remain crucial to developing more effective treatments. This multidisciplinary approach, incorporating diagnostics, personalized therapy, and supportive care, aims to improve outcomes and provides a hopeful foundation for advancing glioblastoma management.

Elevated Serum IL-6 as a Negative Prognostic Biomarker in Glioblastoma: Integrating Bioinformatics and Clinical Validation

Background: Glioblastoma multiforme (GBM) is the most lethal type of primary brain tumor, necessitating the discovery of reliable serum prognostic biomarkers. This study aimed to investigate the prognostic value of serum Interleukin-6 (IL-6) in GBM patients. Methods: Bioinformatics analysis via gene set enrichment analysis was conducted on The Cancer Genome Atlas RNA-seq data to explore the pathways enriched in samples with high IL-6 expression. The Tumor IMmune Estimation Resource database was used to analyze the association between IL-6 expression and immune cell infiltration. To validate the role of IL-6 in a clinical setting, a retrospective cohort study was conducted on newly diagnosed GBM patients. Serum IL-6 levels were repeatedly measured at key milestone time points, and their correlation with survival data was analyzed. Results: Bioinformatics analysis revealed that high IL-6 expression is associated with the activation of procancer pathways, that there is a positive correlation between IL-6 expression and immune cell infiltration in GBM. Between March 2021 and September 2023, 36 GBM patients and their serum IL-6 measurements at various time points were included in the clinical data analyses. Elevated serum IL-6 levels at baseline, with a cutoff of 7pg/mL, were identified in 11 patients (30.6%). In the multivariate analyses for overall survival (OS), elevated IL-6 was a significant risk factor (p = 0.048), along with unfavorable surgical resection (p = 0.039) and O6-methylguanine-DNA methyltransferase promotor unmethylation (p = 0.027). The median actuarial OS of the high initial IL-6 group was significantly shorter than that of the low initial IL-6 group (6.4 vs. 19.7 months, p < 0.001). However, IL-6 levels at other time points were not related to patient prognosis. Conclusion: Elevated IL-6 mRNA expression is correlated with the activation of procancer pathways, increased immune cell infiltration, and poor prognosis in GBM patients. In addition, elevated serum IL-6 at baseline is a negative prognostic factor confirmed in a clinical study. Serum IL-6 may be a potential prognostic biomarker enhancing the management of GBM.

Quantitative assessment of the generalizability of a brain tumor Raman spectroscopy machine learning model to various tumor types including astrocytoma and oligodendroglioma

Significance

Maximal safe resection of brain tumors can be performed by neurosurgeons through the use of accurate and practical guidance tools that provide real-time information during surgery. Current established adjuvant intraoperative technologies include neuronavigation guidance, intraoperative imaging (MRI and ultrasound), and 5-ALA for fluorescence-guided surgery.

Aim

We have developed intraoperative Raman spectroscopy as a real-time decision support system for neurosurgical guidance in brain tumors. Using a machine learning model, trained on data from a multicenter clinical study involving 67 patients, the device achieved diagnostic accuracies of 91% for glioblastoma, 97% for brain metastases, and 96% for meningiomas. Here, the aim is to assess the generalizability of a predictive model trained with data from this study to other types of brain tumors.

Approach

A method was developed to assess the generalizability of the model, quantifying performance for tumors including astrocytoma, oligodendroglioma and ependymoma, pediatric glioblastoma, and classification of glioblastoma data acquired in the presence of 5-ALA induced fluorescence. Statistical analyses were conducted to assess the impact of vibrational bands beyond contributors identified in our previous research.

Results

A machine learning brain tumor detection model showed a positive predictive value (PPV) of 70% for astrocytoma, 74% for oligodendroglioma, and 100% for ependymoma. Furthermore, the PPV was 100% in classifying spectra from a pediatric glioblastoma and 90% for detecting adult glioblastoma labeled with 5-ALA-induced fluorescence. Univariate statistical analyses applied to individual vibrational bands demonstrated that the inclusion of Raman biomarkers unexploited to date had the potential to improve detectability, setting the stage for future advances.

Conclusions

Developing predictive models relying on the inelastic scattering contrast from a wider pool of Raman bands may improve detection accuracy for astrocytoma and oligodendroglioma. To do so, larger tumor datasets and a higher Raman photon signal-to-noise ratio may be required.

Residual Pattern of the Hyperintense Area on T2-Weighted Magnetic Resonance Imaging After Initial Treatment Predicts the Pattern and Location of Recurrence in Patients with Newly Diagnosed Glioblastoma

OBJECTIVE

This study examined the clinical significance of residual hyperintense area on T2-weighted magnetic resonance imaging (T2R) without gadolinium-enhanced lesions at the end of initial treatment (debulking surgery, concomitant radiotherapy, and temozolomide) in patients with glioblastoma.

METHODS

Among 150 glioblastoma cases, 77 cases without enhanced lesions at the end of initial treatment and without factors modifying the distribution of residual hyperintense area or pattern of recurrence were included. We retrospectively reviewed the relationship of residual hyperintense area after initial treatment with progression-free survival (PFS), overall survival (OS), and pattern of recurrence.

RESULTS

In these 77 cases, the median PFS and OS were 12.4 and 27.4 months, respectively. At the end of initial treatment, 55 (71.4%) cases had residual hyperintense area (T2 residual group, T2R), whereas 22 (28.6%) showed no hyperintense area (T2 disappeared group, disappeared hyperintense area on T2-weighted magnetic resonance imaging [T2D]). Based on univariate and multivariate analyses, the residual hyperintense area after initial treatment was not a prognostic factor for PFS or OS. Distant recurrences occurred more frequently in the T2D group than in the T2R group 50.0% versus 9.5%. In the T2R group, the recurrence site coincided with the residual hyperintense area in 36 (85.7%) of 42 recurrences.

CONCLUSIONS

The T2R at the end of initial treatment can predict local recurrence. However, the distant recurrence occurred frequently in T2D group. Thus, attention should be paid to local recurrences in T2R group and distant recurrences in T2D group.

Stem the blood flow: beneficial impact of bevacizumab on survival of subventricular zone glioblastoma patients

PURPOSE

Angiogenesis is a crucial step in tumorigenesis of glioblastoma (GBM). Bevacizumab, an anti-vascular endothelial growth factor drug, is approved for second-line therapy for GBM. Glioma stem cells, presumably the cell of origin of GBM, take an active role in angiogenesis. The subventricular zone (SVZ) is the brain's largest reservoir of neural stem cells, and GBM near this region (SVZ GBM) is associated with a poor prognosis. This study aims to evaluate the potential impact of second-line bevacizumab treatment on survival in patients with SVZ GBM.

METHODS

The electronic medical records of adult patients with newly diagnosed SVZ GDM under treated between 1/2011 and 12/2021 were retrospectively reviewed. Clinical, surgical, radiological, and outcome parameters were compared between patients treated with bevacizumab after first relapse to patients without such treatment.

RESULTS

The cohort included 67 patients. 45 (67.1%) were treated with bevacizumab after the first relapse while 22 (32.9%) were not. The only statistically significant difference between groups was the rate of re-surgery, which was higher in the non-bevacizumab group (40.9% vs. 15.6%; p = 0.023), indicating that the groups were quite homogenous. In general, bevacizumab as a second-line treatment did not affect OS in SVZ GBM cases. However, it significantly prolongs survival time from 1st relapse by an average of more than 4 months, including after adjustment to re-surgery variable (HR = 0.57, 95% CI 0.34-0.94, p = 0.028 and HR = 0.57, 95%CI = 0.34-0.97, PV = 0.038; respectively). Furthermore, when adjusting to time from diagnosis to 1st relapse, bevacizumab treatment was also associated with prolonged OS (HR = 0.58; p = 0.043). In a subgroup analysis, comparing patients treated with both re-surgery and bevacizumab to patients treated in any other way, patients with the combined treatment had the longest mean OS of the entire cohort (22.16 ± 7.81 m vs. 13.60 ± 6.86, p = 0.049; HR = 0.361 95%CI 0.108-1.209, p = 0.085).

CONCLUSIONS

The use of bevacizumab as a second-line therapy in SVZ GBM cases may positively affect survival after relapse, even when given as a monotherapy. Additionally, in certain yet-to-be-identified sub-populations, bevacizumab may even extend overall survival. Further research is required to accurately identify SVZ GBM patients who would benefit most from anti-angiogenic therapy.

Foundation models for fast, label-free detection of glioma infiltration

A critical challenge in glioma treatment is detecting tumour infiltration during surgery to achieve safe maximal resection1-3. Unfortunately, safely resectable residual tumour is found in the majority of patients with glioma after surgery, causing early recurrence and decreased survival4-6. Here we present FastGlioma, a visual foundation model for fast (<10 s) and accurate detection of glioma infiltration in fresh, unprocessed surgical tissue. FastGlioma was pretrained using large-scale self-supervision (around 4 million images) on rapid, label-free optical microscopy, and fine-tuned to output a normalized score that indicates the degree of tumour infiltration within whole-slide optical images. In a prospective, multicentre, international testing cohort of patients with diffuse glioma (n = 220), FastGlioma was able to detect and quantify the degree of tumour infiltration with an average area under the receiver operating characteristic curve of 92.1 ± 0.9%. FastGlioma outperformed image-guided and fluorescence-guided adjuncts for detecting tumour infiltration during surgery by a wide margin in a head-to-head, prospective study (n = 129). The performance of FastGlioma remained high across diverse patient demographics, medical centres and diffuse glioma molecular subtypes as defined by the World Health Organization. FastGlioma shows zero-shot generalization to other adult and paediatric brain tumour diagnoses, demonstrating the potential for our foundation model to be used as a general-purpose adjunct for guiding brain tumour surgeries. These findings represent the transformative potential of medical foundation models to unlock the role of artificial intelligence in the care of patients with cancer.

Predicting glioblastoma progression using MR diffusion tensor imaging: A systematic review

BACKGROUND AND PURPOSE

Despite multimodal treatment of glioblastoma (GBM), recurrence beyond the initial tumor volume is inevitable. Moreover, conventional MRI has shortcomings that hinder the early detection of occult white matter tract infiltration by tumor, but diffusion tensor imaging (DTI) is a sensitive probe for assessing microstructural changes, facilitating the identification of progression before standard imaging. This sensitivity makes DTI a valuable tool for predicting recurrence. A systematic review was therefore conducted to investigate how DTI, in comparison to conventional MRI, can be used for predicting GBM progression.

METHODS

We queried three databases (PubMed, Web of Science, and Scopus) using the search terms: (diffusion tensor imaging OR DTI) AND (glioblastoma OR GBM) AND (recurrence OR progression). For included studies, data pertaining to the study type, number of GBM recurrence patients, treatment type(s), and DTI-related metrics of recurrence were extracted.

RESULTS

In all, 16 studies were included, from which there were 394 patients in total. Six studies reported decreased fractional anisotropy in recurrence regions, and 2 studies described the utility of connectomics/tractography for predicting tumor migratory pathways to a site of recurrence. Three studies reported evidence of tumor progression using DTI before recurrence was visible on conventional imaging.

CONCLUSIONS

These findings suggest that DTI metrics may be useful for guiding surgical and radiotherapy planning for GBM patients, and for informing long-term surveillance. Understanding the current state of the literature pertaining to these metrics' trends is crucial, particularly as DTI is increasingly used as a treatment-guiding imaging modality.

Turning attention to tumor-host interface and focus on the peritumoral heterogeneity of glioblastoma

Approximately 90% of glioblastoma recurrences occur in the peritumoral brain zone (PBZ), while the spatial heterogeneity of the PBZ is not well studied. In this study, two PBZ tissues and one tumor tissue sample are obtained from each patient via preoperative imaging. We assess the microenvironment and the characteristics of infiltrating immune/tumor cells using various techniques. Our data indicate there are one or more regions with higher cerebral blood flow in PBZ, which we collectively name the "higher cerebral blood flow interface" (HBI). The HBI exhibited more neovascularization than the "lower cerebral blood flow interfaces" (LBI). The HBI tend to have increased infiltration of macrophages and T lymphocytes infiltration compared with that in LBI. There are more tumor cells in the HBI than in LBI, with substantial differences in the gene expression profiles of these tumor cells. HBI may be the key area of PBZ-targeting therapy after surgical resection.

Radiotherapeutic advances in the management of glioblastoma

Glioblastoma remains a fatal diagnosis despite continuous efforts to improve upon the current standard backbone management paradigm of surgery, radiation therapy, systemic therapy and Tumor Treating Fields. Radiation therapy (RT) plays a pivotal role, with progress recently achieved in multiple key areas of research. The evolving landscape of dose and fractionation schedules and dose escalation options for different patient populations is explored, offering opportunities to better tailor treatment to a patient's overall status and preferences; novel efforts to modify treatment volumes are presented, such as utilizing state-of-the-art MRI-based linear accelerators to deliver adaptive therapy, hoping to reduce normal tissue exposure and treatment-related toxicity; specialized MR techniques and functional imaging using novel PET agents are described, providing improved treatment accuracy and the opportunity to target areas at risk of disease relapse; finally, the role of particle therapy and new altered dose-rate photon and proton therapy techniques in the treatment paradigm of glioblastoma is detailed, aiming to improve tumor control and patient outcome by exploiting novel radiobiological pathways. Improvements in each of these aforementioned areas are needed to make the critical necessary progress and allow for new approaches combining different advanced treatment modalities. This plethora of multiple new treatment options currently under investigation provides hope for a new outlook for patients with glioblastoma in the near future.

Multimodal treatment of glioblastoma with multiple lesions - a multi-center retrospective analysis

OBJECTIVE

The presence of multiple localizations (ML) in glioblastoma is rare and associated with perceived poor prognosis. The aim of this study is to evaluate the impact of a multimodal treatment on progression-free survival (PFS) and overall survival (OS) in ML glioblastoma.

METHODS

Patients presenting with CNS WHO grade 4 glioblastoma with ML to 2 major German Departments of Neurosurgery between January 1st, 2008, to December 31st, 2020 were included in this study. Primary outcome parameters were extent of resection (EOR) using the 2021 RANO criteria, progression free- and overall survival.

RESULTS

A total of 483 patients with newly diagnosed glioblastoma (CNS WHO grade 4) were assessed. 134 patients presented with ML (72 multifocal (MF), 62 multicentric (MC)). The median PFS and OS did not differ among MC and MF glioblastomas. The EOR was a significant predictor of PFS and OS in ML glioblastoma. complete-, near total-, and subtotal resection significantly prolonged PFS (p < 0.0001) and OS (p < 0.0001) compared to biopsy alone. Standard radiotherapy (p = 0.045) and hypofractionated (p < 0.0001) radiotherapy and adjuvant treatment (Stupp protocol) prolonged PFS (p = 0.0012) and OS (p < 0.0001). In multivariate analysis Karnfosky performance score, EOR, and concomitant adjuvant treatment remained significant factors influencing OS. Propensity score matching of patients with ML and solitary lesion tumors showed similar PFS and OS (p = 0.08).

CONCLUSION

The presented data suggests that glioblastomas with multiple lesions treated with multimodal therapy equal survival rates compared to patients with solitary lesion tumors can be achieved. The results reflect the importance of an equally aggressive maximal treatment effort in this particular and often marginalized group of patients.

Intraoperative label-free tissue diagnostics using a stimulated Raman histology imaging system with artificial intelligence: An initial experience

BACKGROUND

Accurate intraoperative tissue diagnostics could impact on decision making regarding the extent of resection (EOR) during brain tumor surgery. Stimulated Raman histology (SRH) is a label-free optical imaging method that uses different biochemical properties of tissue to generate a hematoxylin-eosin-like image and, in combination with an artificial intelligence-based image classifier, offers the opportunity to obtain rapid intraoperative tissue diagnoses.

OBJECTIVE

The goal of this study was to report on our initial experience with SRH to evaluate its accuracy in comparison to final tissue diagnosis.

MATERIALS & METHODS

We evaluated 70 consecutive adult cases with brain tumors. We compared results of the three different SRH classifier (diagnostic, molecular and tumor/non-tumor) to the respective final histopathological result. Similarly, we evaluated the isocitrate dehydrogenase (IDH) mutations in 18 patients using SRH. Lastly, we compared SRH results of samples taken from the tumor margins with early postoperative MRI. Prediction accuracy was evaluated by logistic regression and Receiver Operator Curve (ROC) analysis.

RESULTS

We included 19 gliomas, 9 metastases, 22 meningiomas and 14 other tumor entities. Regarding accuracy of intraoperative SRH predictions, regression analysis showed an Area Under the Curve (AUC) of 0.77 (95 % C.I. 0.64-0.89, p = 0.0008), suggesting agreement of predictions with final diagnosis. For specific tumor entities, variable accuracies were observed: The highest accuracy was obtained for meningiomas followed by high-grade glioma. IDH mutations were predicted with an AUC of 0.93 (95 % C.I. 0.88-0.98; p < 0.0001). The SRH examination of tissue samples from tumor margins corresponded with postoperative MRI in 4 out of 5 cases.

CONCLUSION

Our initial experience with SRH shows that this novel imaging technique is a promising approach to obtain rapid intraoperative tissue diagnosis to guide surgical decision making based on histology and cell-density. With further refinement of AI-based automated image classification and a better integration into the surgical workflow, prediction accuracy and reliability could be improved.

Characterization of Polarimetric Properties in Various Brain Tumor Types Using Wide-Field Imaging Mueller Polarimetry

Neuro-oncological surgery is the primary brain cancer treatment, yet it faces challenges with gliomas due to their invasiveness and the need to preserve neurological function. Hence, radical resection is often unfeasible, highlighting the importance of precise tumor margin delineation to prevent neurological deficits and improve prognosis. Imaging Mueller polarimetry, an effective modality in various organ tissues, seems a promising approach for tumor delineation in neurosurgery. To further assess its use, we characterized the polarimetric properties by analysing 45 polarimetric measurements of 27 fresh brain tumor samples, including different tumor types with a strong focus on gliomas. Our study integrates a wide-field imaging Mueller polarimetric system and a novel neuropathology protocol, correlating polarimetric and histological data for accurate tissue identification. An image processing pipeline facilitated the alignment and overlay of polarimetric images and histological masks. Variations in depolarization values were observed for grey and white matter of brain tumor tissue, while differences in linear retardance were seen only within white matter of brain tumor tissue. Notably, we identified pronounced optical axis azimuth randomization within tumor regions. This study lays the foundation for machine learning-based brain tumor segmentation algorithms using polarimetric data, facilitating intraoperative diagnosis and decision making.

In Situ Light-Source Delivery During 5-Aminulevulinic Acid-Guided High-Grade Glioma Resection: Spatial, Functional and Oncological Informed Surgery

BACKGROUND/OBJECTIVES

5-aminulevulinic acid (5-ALA)-guided surgery for high-grade gliomas remains a challenge in neuro-oncological surgery. Inconsistent fluorescence visualisation, subjective quantification and false negatives due to blood, haemostatic agents or optical impediments from the external light source are some of the limitations of the present technology.

METHODS

The preliminary results from this single-centre retrospective study are presented from the first 35 patients operated upon with the novel Nico Myriad Spectra System©. The microdebrider (Myriad) with an additional in situ light system (Spectra) can alternately provide white and blue light (405 nm) to within 15 mm of the tissue surface to enhance the morphology of the anatomical structures and the fluorescence of the pathological tissues.

RESULTS

A total of 35 patients were operated upon with this new technology. Eight patients (22.85%) underwent tubular retractor-assisted minimally invasive parafascicular surgery (tr-MIPS). The majority had high-grade gliomas (68.57%). Fluorescence was identified in 30 cases (85.71%), with residual fluorescence in 11 (36.66%). The main applications were better white-blue light alternation and visualisation during tr-MIPS, increase in the extent of resection at the border of the cavity, identification of satellite lesions in multifocal pathology, the differentiation between radionecrosis and tumour recurrence in redo surgery and the demarcation between normal ependyma versus pathological ependyma in tumours infiltrating the subventricular zone.

CONCLUSIONS

This proof-of-concept study confirms that the novel in situ light-source delivery technology integrated with the usual intraoperative armamentarium provides a spatially, functionally and oncologically informed framework for glioblastoma surgery. It allows for the enhancement of the morphology of anatomical structures and the fluorescence of pathological tissues, increasing the extent of resection and, possibly, the prognosis for patients with high-grade gliomas.

Decoding Glioblastoma Heterogeneity: Neuroimaging Meets Machine Learning

Recent advancements in neuroimaging and machine learning have significantly improved our ability to diagnose and categorize isocitrate dehydrogenase (IDH)-wildtype glioblastoma, a disease characterized by notable tumoral heterogeneity, which is crucial for effective treatment. Neuroimaging techniques, such as diffusion tensor imaging and magnetic resonance radiomics, provide noninvasive insights into tumor infiltration patterns and metabolic profiles, aiding in accurate diagnosis and prognostication. Machine learning algorithms further enhance glioblastoma characterization by identifying distinct imaging patterns and features, facilitating precise diagnoses and treatment planning. Integration of these technologies allows for the development of image-based biomarkers, potentially reducing the need for invasive biopsy procedures and enabling personalized therapy targeting specific pro-tumoral signaling pathways and resistance mechanisms. Although significant progress has been made, ongoing innovation is essential to address remaining challenges and further improve these methodologies. Future directions should focus on refining machine learning models, integrating emerging imaging techniques, and elucidating the complex interplay between imaging features and underlying molecular processes. This review highlights the pivotal role of neuroimaging and machine learning in glioblastoma research, offering invaluable noninvasive tools for diagnosis, prognosis prediction, and treatment planning, ultimately improving patient outcomes. These advances in the field promise to usher in a new era in the understanding and classification of IDH-wildtype glioblastoma.

Comparative efficacy of awake and asleep motor mapping in glioma surgery: A meta-analysis of 3011 patients

Standard of care in glioma surgery involves maximal-safe resection. Intraoperative stimulation mapping can improve the extent of resection in eloquent area tumors. Resection is performed during awake craniotomy (AC) or under general anesthesia (GA). Considering the advances in glioma management, an updated meta-analysis is needed. We identified studies evaluating surgical outcomes in adult patients undergoing glioma resection in motor areas, comparing AC and GA mapping until November 2023. Twenty-four observational studies and one randomized controlled trial met our inclusion criteria, adding 3011 patients. The mean extent of resection was 92.2% (95%CI = 89.9%-94.5%) for AC and 92.5% (95%CI = 89.6%-95.3%) for GA. Immediate deficit revealed a nonsignificant risk ratio (RR) of 0.96 favoring AC (95%CI = 0.66-1.41, p = 0.84). Similarly, long-term deficits showed a nonsignificant RR of 1.33 favoring GA (95%CI = 0.91-1.95, p = 0.14). Karnofsky performance score (KPS) analysis revealed a nonsignificant mean difference of 2.32 favoring GA (95%CI = -6.10-10.73, p = 0.59). Intraoperative stimulation-induced seizures analysis yielded a nonsignificant RR of 0.73 (95% CI = 0.27-1.97, p = 0.53) favoring AC. Postoperative seizure analysis showed a significant RR of 0.64 (95% CI = 0.44-0.94, p = 0.02) favoring AC. This meta-analysis suggests that AC and GA are comparable approaches to maximize extent of resection and achieve safe resection in eloquent glioma surgery. These findings can offer guidance to neurosurgeons in the decision-making process.

Supratotal Resection Versus Gross Total Resection for Isocitrate Dehydrogenase-Wildtype Glioblastoma and Grade 4 Isocitrate Dehydrogenase-Mutant Astrocytoma: Meta-Analysis of Individual Patient Data

BACKGROUND AND OBJECTIVES

IDH-wildtype glioblastoma multiforme (GBM) and grade 4 IDH-mutant astrocytoma are challenging to manage in oncology. This study explores the contrast between gross total resection (GTR) and supratotal resection (SupTR) for IDH-wildtype GBM and grade 4 IDH-mutant astrocytoma, aiming to summarize their influence on crucial clinical outcomes.

METHODS

This systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. PubMed, Web of Science, Embase, Scopus, and Cochrane were searched for articles until December 2023.

RESULTS

Ten studies were included, involving 1043 patients with IDH-wildtype GBM and grade 4 IDH-mutant astrocytoma who underwent GTR or SupTR. SupTR demonstrated a favorable impact on long-term overall survival (OS) and progression-free survival (PFS) compared with GTR. The hazard ratio for OS was 0.655 (95% CI: 0.5703-0.7522, P < .0001), and for PFS, it was 0.732 (95% CI: 0.6279-0.8540, P = .0001) in the long-term analysis. Short-term analysis (18 months) reinforced the superiority of SupTR, with a hazard ratio for OS of 0.544 (95% CI: 0.450-0.659, P < .0001), and for PFS, it was 0.697 (95% CI: 0.586-0.830, P < .0001) in this timespan.

CONCLUSION

SupTR appears to be a promising alternative to GTR for treating IDH-wildtype GBM and grade 4 IDH-mutant astrocytoma, showing improved OS and PFS outcomes. More robust studies that are less susceptible to bias are needed to strengthen this conclusion.

The prognostic importance of glioblastoma size and shape

PURPOSE

Extent of resection, MGMT promoter methylation status, age, functional level, and residual tumor volume are established prognostic factors for overall survival in glioblastoma patients. Preoperative tumor volume has also been investigated, but the results have been inconclusive. We hypothesized that the surface area and the shape were more representative of the tumor's infiltrative capacities, and thus, the purpose of this study was to assess the prognostic value of tumor size and shape in patients with glioblastoma.

METHODS

In total, 271 patients with primary, unifocal glioblastoma were included from two centers in Norway and Sweden, respectively. All tumors were automatically segmented on preoperative MRI scans and manually validated. Tumor volume was used as a measurement of size, whereas sphericity index and area-to-volume ratio defined the shape complexity of the tumor. Contact surface area of the tumor was considered a measurement of both size and shape. Multivariable Cox proportional hazards models were used to assess the prognostic value of the respective tumor measurements, with previously established prognostic factors as covariates.

RESULTS

There were no associations between preoperative tumor volume and overall survival. Contact surface area (HR = 1.013, p = 0.002) and sphericity index (HR = 2.223, p = 0.001) were both significant independent prognostic factors for survival in the multivariable Cox models. Contact surface area was also associated with MGMT promoter methylation (p = 0.039) and extent of resection (p = 0.017).

CONCLUSION

Tumor shape complexity appears to be an independent prognostic factor in glioblastoma patients and may also be associated with MGMT promoter methylation status and extent of surgical resection.

Clinical Benefits of Photodynamic Therapy Using Talaporfin Sodium in Patients With Isocitrate Dehydrogenase-Wildtype Diagnosed Glioblastoma: A Retrospective Study of 100 Cases

BACKGROUND AND OBJECTIVES

Photodynamic therapy (PDT) with talaporfin sodium is an intraoperative local therapy administered after the surgical removal of malignant gliomas. However, its clinical efficacy in a large patient population has not been determined. To analyze the clinical outcomes and prognosis in isocitrate dehydrogenase (IDH)-wildtype glioblastoma patients treated with PDT.

METHODS

This retrospective study included patients with newly diagnosed IDH-wildtype glioblastoma treated at Kobe University Hospital between January 2013 and December 2022. PDT involves irradiation of the resection cavity with a 664-nm semiconductor laser after an intravenous infusion of talaporfin sodium. The main outcome measures were the recurrence patterns and survival times, which were compared between the PDT and non-PDT groups. Univariate and multivariate analyses were used to determine the prognostic factors. In addition, adverse events and prognostic factors in the PDT group were analyzed.

RESULTS

A total of 44 and 56 patients were included in the PDT and non-PDT groups, respectively. The local recurrence rate was significantly lower in the PDT group than in the non-PDT group (51.3% vs 83.9%), whereas the distant recurrence and dissemination rates were significantly higher in the PDT group than in the non-PDT group (48.7% vs 16.1%). Two grade 3 adverse events were observed in the PDT group. The median progression-free survival and overall survival times were significantly longer in the PDT group than in the non-PDT group (progression-free survival: 10.8 vs 9.3 months, respectively, and overall survival: 24.6 vs 17.6 months, respectively). Multivariate analysis of the PDT groups revealed that younger age was an independent prognostic factor.

CONCLUSION

PDT with talaporfin sodium provided effective local control with minimal adverse effects. The survival time of the patients treated with PDT was significantly longer than that of the patients who did not receive PDT. Therefore, a randomized controlled clinical trial on PDT is warranted.

The Infiltrative Margins in Glioblastoma: Important Is What Has Been Left behind

Supramaximal resection beyond the contrast-enhancing tumor borders represents an emerging surgical strategy for patients with newly diagnosed glioblastoma. A recent study provides evidence detailing the interactive effects of more aggressive surgery on other clinical predictors of outcome, supporting guidance for surgical decision-making and informing clinical trialists about the need to stratify for extent of resection. See related article by Park et al., p. 4866.

Systemic inflammatory markers and volume of enhancing tissue on post-contrast T1w MRI images in differentiating true tumor progression from pseudoprogression in high-grade glioma

Background

High-grade glioma (HGG) patients post-radiotherapy often face challenges distinguishing true tumor progression (TTP) from pseudoprogression (PsP). This study evaluates the effectiveness of systemic inflammatory markers and volume of enhancing tissue on post-contrast T1 weighted (T1WCE) MRI images for this differentiation within the first six months after treatment.

Material and Methods

We conducted a retrospective analysis on a cohort of HGG patients from 2015 to 2021, categorized per WHO 2016 and 2021 criteria. We analyzed treatment responses using modified RANO criteria and conducted volumetry on T1WCE and T2W/FLAIR images.Blood parameters assessed included neutrophil/lymphocyte ratio (NLR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI). We employed Chi-square, Fisher's exact test, and Mann-Whitney U test for statistical analyses, using log-transformed predictors due to multicollinearity. A Cox regression analysis assessed the impact of PsP- and TTP-related factors on overall survival (OS).

Results

The cohort consisted of 39 patients, where 16 exhibited PsP and 23 showed TTP. Univariate analysis revealed significantly higher NLR and SII in the TTP group [NLR: 4.1 vs 7.3, p = 0.002; SII 546.5 vs 890.5p = 0.009]. T1WCE volume distinctly differentiated PsP from TTP [2.2 vs 11.7, p < 0.001]. In multivariate regression, significant predictors included NLR and T1WCE volume in the "NLR Model," and T1WCE volume and SII in the "SII Model." The study also found a significantly lower OS rate in TTP patients compared to those with PsP [HR 3.97, CI 1.59 to 9.93, p = 0.003].

Conclusion

Elevated both, SII and NLR, and increased T1WCE volume were effective in differentiating TTP from PsP in HGG patients post-radiotherapy. These results suggest the potential utility of incorporating these markers into clinical practice, though further research is necessary to confirm these findings in larger patient cohorts.

Incorporating Supramaximal Resection into Survival Stratification of IDH-wildtype Glioblastoma: A Refined Multi-institutional Recursive Partitioning Analysis

PURPOSE

To propose a novel recursive partitioning analysis (RPA) classification model in patients with IDH-wildtype glioblastomas that incorporates the recently expanded conception of the extent of resection (EOR) in terms of both supramaximal and total resections.

EXPERIMENTAL DESIGN

This multicenter cohort study included a developmental cohort of 622 patients with IDH-wildtype glioblastomas from a single institution (Severance Hospital) and validation cohorts of 536 patients from three institutions (Seoul National University Hospital, Asan Medical Center, and Heidelberg University Hospital). All patients completed standard treatment including concurrent chemoradiotherapy and underwent testing to determine their IDH mutation and MGMTp methylation status. EORs were categorized into either supramaximal, total, or non-total resections. A novel RPA model was then developed and compared with a previous Radiation Therapy Oncology Group (RTOG) RPA model.

RESULTS

In the developmental cohort, the RPA model included age, MGMTp methylation status, Karnofsky performance status, and EOR. Younger patients with MGMTp methylation and supramaximal resections showed a more favorable prognosis [class I: median overall survival (OS) 57.3 months], whereas low-performing patients with non-total resections and without MGMTp methylation showed the worst prognosis (class IV: median OS 14.3 months). The prognostic significance of the RPA was subsequently confirmed in the validation cohorts, which revealed a greater separation between prognostic classes for all cohorts compared with the previous RTOG RPA model.

CONCLUSIONS

The proposed RPA model highlights the impact of supramaximal versus total resections and incorporates clinical and molecular factors into survival stratification. The RPA model may improve the accuracy of assessing prognostic groups. See related commentary by Karschnia et al., p. 4811.

Survival Determinants in Glioblastoma: An Insight into Biopsy-Only Patient Outcomes

Background: Glioblastoma is a challenge in neuro-oncology, with survival significantly influenced mainly by the extent of resection and molecular markers. Despite advancements, the prognosis for IDH-wildtype glioblastoma remains poor, particularly when surgical resection is not possible. However, some patients exhibit unexpectedly extended survival despite the extent of resection. This study aims to analyze the determinants that contribute to these atypical survival rates among glioblastoma patients who have had solely biopsy procedures. Methods: We conducted a retrospective analysis of patients diagnosed with IDH-wildtype glioblastomas at our institution from 2017 to 2021, who underwent biopsy only. This study focused on evaluating the impact of demographic characteristics, clinical features, molecular markers, and treatment modalities on survival outcomes (overall survival (OS) and progression-free survival (PFS)). Statistical analyses included survival analysis and logistic regression for evaluating associations between OS and pre-operative characteristics and post-operative treatments. Results: The cohort included 99 patients, with a median age at diagnosis of 65.5 years. Median OS and PFS were 6.0 and 3.6 months, respectively. The multivariate analysis revealed that higher Karnofsky Performance Status (KPS) scores before biopsy, no contrast uptake on imaging, and any adjuvant therapy, particularly the use of bevacizumab, were independently associated to increased OS (HR = 0.97, p = 0.009. HR = 0.7, p = 0.015; HR = 0.27, p = 0.002, respectively). Out of 99 patients, 77.8% survived past the 3-month threshold, with 87.0% of this receiving adjuvant treatment. Only 8% of patients survived past 24 months, and in this group of patients, MGMT methylation was observed in just 25% of cases. Kaplan-Meier analysis indicated a better prognosis with any type of adjuvant therapy across all patients, particularly so in those with KPS ≥ 70. Age did not significantly affect survival outcomes (OR = 1.00, p = 0.835). Conclusion: Our findings reveal that any adjuvant treatment (whether chemotherapy and radiotherapy combined, chemotherapy alone, or bevacizumab), no contrast uptake on imaging, and higher pre-operative KPS are key determinants of survival in IDH-wildtype glioblastoma and should therefore be considered when deciding whether to perform a biopsy.

MGMT methylation and its prognostic significance in inoperable IDH-wildtype glioblastoma: the MGMT-GBM study

INTRODUCTION

The methylation of the O6-Methylguanine-DNA Methyltransferase (MGMT) promoter is a valid biomarker for predicting response to therapy with alkylating agents and, independently, prognosis in IDH-wildtype(IDH-w) glioblastoma. We aim to study the impact of its methylation in overall survival of the unresectable IDH-w glioblastoma undergoing biopsy and systemic treatment.

METHODS

We collected six-year retrospective (2017-2023) data at a quaternary neurosurgery center for patients undergoing biopsy as the only surgical procedure for an unresectable IDH wildtype glioblastoma. Data was collected from patient records including neuro-oncology multidisciplinary team meeting (MDT) documentation. Patients were grouped into categories according to different types of treatment received after biopsy (no treatment, chemotherapy (CT), radiotherapy (RT), chemoradiotherapy (CRT), chemoradiotherapy with adjuvant temozolomide (CRT with adjuvant TMZ), EORTC-NCIC protocol followed by second line treatment) and according to methylation status (unmethylated (< 5%), borderline methylated (5-15%) and strongly methylated (> 15%)). Survival analysis was performed.

RESULTS

166 glioblastoma IDH wildtype patients were included in the study with mean age of 62.5 years (M: F = 1.5: 1). 70 (49.3%) patients had unmethylated MGMT status (< 5%), 29 (20.4%) patients had borderline methylated MGMT status (5-15%) and 43 (30.2%) patients had methylated MGMT status (> 15%). 36 (25.3%) patients did not receive any treatment post biopsy, 13 (9.1%) received CT only, 27 (19%) RT only, 12 (8.4%) CRT, 33 (23.2%) CRT with adjuvant TMZ, whereas 21 (14.7%) received EORTC-NCIC protocol along with second line treatment. In biopsy only group, there was no notable difference in survival outcomes among the different methylation statuses. For biopsy and any-other-form-of-treatment methylated groups showed a distinct trend of better survival compared to the borderline or unmethylated groups. Overall, methylated patients had better survival as compared to unmethylated or borderline groups.

CONCLUSION

Methylated MGMT status are predictors for better overall survival in unresectable IDH wildtype glioblastoma patients undergoing biopsy and treatment regardless of the treatment modality.

Leptomeningeal metastases in isocitrate dehydrogenase-wildtype glioblastomas revisited: Comprehensive analysis of incidence, risk factors, and prognosis based on post-contrast fluid-attenuated inversion recovery

BACKGROUND

The incidence of leptomeningeal metastases (LM) has been reported diversely. This study aimed to investigate the incidence, risk factors, and prognosis of LM in patients with isocitrate dehydrogenase (IDH)-wildtype glioblastoma.

METHODS

A total of 828 patients with IDH-wildtype glioblastoma were enrolled between 2005 and 2022. Baseline preoperative MRI including post-contrast fluid-attenuated inversion recovery (FLAIR) was used for LM diagnosis. Qualitative and quantitative features, including distance between tumor and subventricular zone (SVZ) and tumor volume by automatic segmentation of the lateral ventricles and tumor, were assessed. Logistic analysis of LM development was performed using clinical, molecular, and imaging data. Survival analysis was performed.

RESULTS

The incidence of LM was 11.4%. MGMTp unmethylation (odds ratio [OR] = 1.92, P = .014), shorter distance between tumor and SVZ (OR = 0.94, P = .010), and larger contrast-enhancing tumor volume (OR = 1.02, P < .001) were significantly associated with LM. The overall survival (OS) was significantly shorter in patients with LM than in those without (log-rank test; P < .001), with median OS of 12.2 and 18.5 months, respectively. The presence of LM remained an independent prognostic factor for OS in IDH-wildtype glioblastoma (hazard ratio = 1.42, P = .011), along with other clinical, molecular, imaging, and surgical prognostic factors.

CONCLUSIONS

The incidence of LM is high in patients with IDH-wildtype glioblastoma, and aggressive molecular and imaging factors are correlated with LM development. The prognostic significance of LM based on post-contrast FLAIR imaging suggests the acknowledgment of post-contrast FLAIR as a reliable diagnostic tool for clinicians.