OBJECTIVE: While the effect of increased extent of resection (EOR) on survival in diffuse infiltrating low-grade glioma (LGG) patients is well established, there is still uncertainty about the influence of the new WHO molecular subtypes. The authors designed a retrospective analysis to assess the interplay between EOR and molecular classes.METHODS: The authors retrospectively reviewed the records of 326 patients treated surgically for hemispheric WHO grade II LGG at Brigham and Women’s Hospital and Massachusetts General Hospital (2000–2017). EOR was calculated volumetrically and Cox proportional hazards models were built to assess for predictive factors of overall survival (OS), progression-free survival (PFS), and malignant progression–free survival (MPFS).RESULTS: There were 43 deaths (13.2%; median follow-up 5.4 years) among 326 LGG patients. Median preoperative tumor volume was 31.2 cm³ (IQR 12.9–66.0), and median postoperative residual tumor volume was 5.8 cm³ (IQR 1.1–20.5). On multivariable Cox regression, increasing postoperative volume was associated with worse OS (HR 1.02 per cm³; 95% CI 1.00–1.03; p = 0.016), PFS (HR 1.01 per cm³; 95% CI 1.00–1.02; p = 0.001), and MPFS (HR 1.01 per cm³; 95% CI 1.00–1.02; p = 0.035). This result was more pronounced in the worse prognosis subtypes of IDH-mutant and IDH-wildtype astrocytoma, for which differences in survival manifested in cases with residual tumor volume of only 1 cm³. In oligodendroglioma patients, postoperative residuals impacted survival when exceeding 8 cm³. Other significant predictors of OS were age at diagnosis, IDH-mutant and IDH-wildtype astrocytoma classes, adjuvant radiotherapy, and increasing preoperative volume.CONCLUSIONS: The results corroborate the role of EOR in survival and malignant transformation across all molecular subtypes of diffuse LGG. IDH-mutant and IDH-wildtype astrocytomas are affected even by minimal postoperative residuals and patients could potentially benefit from a more aggressive surgical approach.

Accurate brain meningioma segmentation and volumetric assessment are critical for serial patient follow-up, surgical planning and monitoring response to treatment. Current gold standard of manual labeling is a time-consuming process, subject to inter-user variability. Fully-automated algorithms for meningioma segmentation have the potential to bring volumetric analysis into clinical and research workflows by increasing accuracy and efficiency, reducing inter-user variability and saving time. Previous research has focused solely on segmentation tasks without assessment of impact and usability of deep learning solutions in clinical practice. Herein, we demonstrate a three-dimensional convolutional neural network (3D-CNN) that performs expert-level, automated meningioma segmentation and volume estimation on MRI scans. A 3D-CNN was initially trained by segmenting entire brain volumes using a dataset of 10,099 healthy brain MRIs. Using transfer learning, the network was then specifically trained on meningioma segmentation using 806 expert-labeled MRIs. The final model achieved a median performance of 88.2% reaching the spectrum of current inter-expert variability (82.6–91.6%). We demonstrate in a simulated clinical scenario that a deep learning approach to meningioma segmentation is feasible, highly accurate and has the potential to improve current clinical practice.

Butterfly glioblastomas (bGBM) are grade IV gliomas that spread to bilateral hemispheres by infiltrating the corpus callosum. Data on the effect of surgery are limited to small case series. The aim of this meta-analysis was to compare resection vs. biopsy in terms of survival outcomes and postoperative complications. A systematic review of the literature was conducted using PubMed, EMBASE, and Cochrane databases through March 2021 in accordance with the PRISMA checklist. Pooled hazard ratios were calculated and meta-analyzed in a random-effects model including assessment of heterogeneity. Out of 3367 articles, seven studies were included with 293 patients. Surgical resection was significantly associated with longer overall survival (HR 0.39, 95%CI 0.2–0.55) than biopsy. Low heterogeneity was observed (I²: 0%). In further analysis, the effect persisted in extent of resection subgroups of both ≥80% and <80%. No statistically significant difference between surgery and biopsy was detected in terms of postoperative complications, although these were numerically larger for surgery. In patients with bGBM, surgical resection was associated with longer survival prospects compared with biopsy.

BACKGROUND AND OBJECTIVES: The association between extent of resection (EOR) and outcomes after brain metastasis (BM) surgery remains unclear. The aim of this study was to examine the relation between EOR and overall survival (OS)/intracranial progression-free survival (IC-PFS) in this patient group. METHODS: We included patients who underwent BM resection and had postoperative MRI <72 hours. Presence of any residual on MRI was defined as subtotal resection (STR) as opposed to gross total resection. Multivariable analyses were adjusted for known confounders. Post hoc analysis explored the effect size across different subgroups. A secondary outcome was the occurrence of leptomeningeal disease (LMD). RESULTS: We included 867 patients; median age was 61 years (IQR 53-68), and median BM diameter was 3.0 cm (IQR 2.2-3.9). Extracranial metastases were present in 310 (35.8%) patients, and 365 (42.1%) received stereotactic radiosurgery (SRS) to the resection cavity. No residual on MRI was present in 345 patients (39.9%). In multivariable analysis, STR correlated with decreased IC-PFS (hazard ratio [HR] 1.32, 95% CI 1.13-1.55, P < .001) and OS (HR 1.28, 95% CI 1.08-1.53, P = .005) and a higher occurrence of LMD (odds ratio 1.74, 95% CI 1.10-2.76, P = .02). STR + SRS also correlated with decreased IC-PFS compared with gross total resection (HR 1.35, 95% CI 1.02-1.66, P = .04). In subgroup analysis, the strongest association between EOR and outcomes was observed in large (>3 cm) BMs, supratentorial BMs, and patients without extracranial disease. The use of cavity SRS or the number of BMs had little impact on this association. CONCLUSION: Residual tumor on postoperative MRI after BM resection correlated with worse IC-PFS and OS after adjusting for confounding variables. An increased prevalence of LMD may be a possible mechanism through which these patients experience worse outcomes.