Clinical outcomes of solitary fibrous tumors and hemangiopericytomas and risk factors related to recurrence and survival based on the 2021 WHO classification of central nervous system tumors

J Neurosurg 140:69–79, 2024

OBJECTIVE The authors aimed to explore the clinical outcomes and risk factors related to recurrence of and survival from solitary fibrous tumors (SFTs) and hemangiopericytomas (HPCs) that were reclassified according to the 2021 WHO classification of central nervous system (CNS) tumors.

METHODS The authors retrospectively collected and analyzed the clinical and pathological data of SFTs and HPCs recorded from January 2007 to December 2021. Two neuropathologists reassessed pathological slides and regraded specimens on the basis of the 2021 WHO classification. The prognostic factors related to progression-free survival (PFS) and overall survival (OS) were statistically assessed with univariate and multivariate Cox regression analyses.

RESULTS A total of 146 patients (74 men and 72 women, mean ± SD [range] age 46.1 ± 14.3 [3–78] years) were reviewed, and 86, 35, and 25 patients were reclassified as having grade 1, 2, and 3 SFTs on the basis of the 2021 WHO classification, respectively. The median PFS and OS of the patients with WHO grade 1 SFT were 105 months and 199 months after initial diagnosis; for patients with WHO grade 2 SFT, 77 months and 145 months; and for patients with WHO grade 3 SFT, 44 months and 112 months, respectively. Of the entire cohort, 61 patients experienced local recurrence and 31 died, of whom 27 (87.1%) died of SFT and relevant complications. Ten patients had extracranial metastasis. In multivariate Cox regression analysis, subtotal resection (STR) (HR 4.648, 95% CI 2.601–8.304, p < 0.001), tumor located in the parasagittal or parafalx region (HR 2.105, 95% CI 1.099–4.033, p = 0.025), tumor in the vertebrae (HR 3.352, 95% CI 1.228–9.148, p = 0.018), WHO grade 2 SFT (HR 2.579, 95% CI 1.343–4.953, p = 0.004), and WHO grade 3 SFT (HR 5.814, 95% CI 2.887–11.712, p < 0.001) were significantly associated with shortened PFS, whereas STR (HR 3.217, 95% CI 1.435–7.210, p = 0.005) and WHO grade 3 SFT (HR 3.433, 95% CI 1.324–8.901, p = 0.011) were significantly associated with shortened OS. In univariate analyses, patients who received adjuvant radiotherapy (RT) after STR had longer PFS than patients who did not receive RT.

CONCLUSIONS The 2021 WHO classification of CNS tumors better predicted malignancy with different pathological grades, and in particular WHO grade 3 SFT had worse prognosis. Gross-total resection (GTR) can significantly prolong PFS and OS and should serve as the most important treatment method. Adjuvant RT was helpful for patients who underwent STR but not for patients who underwent GTR.

Predictors of Progression-Free Survival in Patients With Spinal Intramedullary Ependymoma: A Multicenter Retrospective Study by the Neurospinal Society of Japan

Neurosurgery 93:1046–1056, 2023

Ependymoma is the most common spinal intramedullary tumor. Although clinical outcomes have been described in the literature, most of the reports were based on limited numbers of cases or been confined to institutional experience. The objective of this study was to analyze more detailed characteristics of spinal intramedullary ependymoma (SIE) and provide clinical factors associated with progression-free survival (PFS).

METHODS: This retrospective observational multicenter study included consecutive patients with SIE in the cervical or thoracic spine treated surgically at a total of 58 institutions between 2009 and 2020. The results of pathological diagnosis at each institute were confirmed, and patients with myxopapillary ependymoma, subependymoma, or unverified histopathology were strictly excluded from this study. Outcome measures included surgical data, surgery-related complications, postoperative systemic adverse events, postoperative adjuvant treatment, postoperative functional condition, and presence of recurrence.

RESULTS: This study included 324 cases of World Health Organization grade II (96.4%) and 12 cases of World Health Organization grade III (3.6%). Gross total resection (GTR) was achieved in 76.5% of cases. Radiation therapy (RT) was applied after surgery in 16 cases (4.8%), all of which received local RT and 5 of which underwent chemotherapy in combination. Functional outcomes were significantly affected by preoperative neurological symptoms, tumor location, extent of tumor resection, and recurrence. Multivariate regression analysis suggested that limited extent of tumor resection or recurrence resulted in poor functional outcomes. Multiple comparisons among the groups undergoing GTR, subtotal resection and biopsy, or partial resection of the tumor showed that the probability of PFS differed significantly between GTR and other extents of resection.

CONCLUSION: When GTR can be safely obtained in the surgery for SIE, functional maintenance and longer PFScan be expected.


The Impact of Extent of Ablation on Survival of Patients With Newly Diagnosed Glioblastoma Treated With Laser Interstitial Thermal Therapy

Neurosurgery 93:427–435, 2023

Upfront laser interstitial thermal therapy (LITT) can be used as part of the treatment paradigm in difficult-to-access newly diagnosed glioblastoma multiforme (ndGBM) cases. The extent of ablation, though, is not routinely quantified; thus, its specific effect on patients’ oncological outcomes is unclear.

OBJECTIVE: To methodically measure the extent of ablation in the cohort of patients with ndGBM and its effect, and other treatment-related parameters, on patients’ progression-free survival (PFS) and overall survival (OS).

METHODS: A retrospective study was conducted on 56 isocitrate dehydrogenase 1/2 wild-type patients with ndGBM treated with upfront LITT between 2011 and 2021. Patient data including demographics, oncological course, and LITTassociated parameters were analyzed.

RESULTS: Patient median age was 62.3 years (31-84), and the median follow-up duration was 11.4 months. As expected, the subgroup of patients receiving full chemoradiation was found to have the most beneficial PFS and OS (n = 34). Further analysis showed that 10 of them underwent near-total ablation and had a significantly improved PFS (10.3 months) and OS (22.7 months). Notably, 84% excess ablation was detected which was not related to a higher rate of neurological deficits. Tumor volume was also found to influence PFS and OS, but it was not possible to further corroborate this finding because of low numbers.

CONCLUSION: This study presents data analysis of the largest series of ndGBM treated with upfront LITT. Near-total ablation was shown to significantly benefit patients’ PFS and OS. Importantly, it was shown to be safe, even in cases of excess ablation and therefore could be considered when using this modality to treat ndGBM.

The impact of multiple lesions on progression-free survival of meningiomas: a 10-year multicenter experience

J Neurosurg 137:9–17, 2022

Multiple meningiomas (MMs) occur in as many as 18% of patients with meningioma, and data on progression- free survival (PFS) are scarce. The objective of this study was to explore the influence of the number of lesions and clinical characteristics on PFS in patients with WHO grade I meningiomas.

METHODS The authors retrospectively reviewed the records of all adults diagnosed with a meningioma at their three main sites from January 2009 to May 2020. Progression was considered the time from diagnosis until radiographic growth of the originally resected meningioma. A secondary analysis was performed to evaluate the time of diagnosis until the time to second intervention (TTSI). Univariable and multivariable analyses were conducted to assess whether the number of lesions or any associated variables (age, sex, race, radiation treatment, tumor location, and extent of resection) had a significant impact on PFS and TTSI.

RESULTS Eight hundred thirty-eight patients were included. Use of a log-rank test to evaluate PFS and TTSI between a single and multiple lesions showed a significantly shorter progression for MM (p < 0.001 and p < 0.001, respectively). Multivariable Cox regression analysis showed significantly inferior PFS on MM compared to a single lesion (hazard ratio [HR] 2.262, 95% confidence interval [CI] 1.392–3.677, p = 0.001) and a significantly inferior TTSI for patients with MM when compared to patients with a single meningioma (HR 2.377, 95% CI 1.617–3.494, p = 0.001). By testing the number of meningiomas as a continuous variable, PFS was significantly inferior for each additional meningioma (HR 1.350, 95% CI 1.074–1.698, p = 0.010) and TTSI was significantly inferior as well (HR 1.428, 95% CI 1.189–1.716, p < 0.001). African American patients had an inferior PFS when compared to non-Hispanic White patients (HR 3.472, 95% CI 1.083–11.129, p = 0.036).

CONCLUSIONS The PFS of meningiomas appears to be influenced by the number of lesions present. Patients with MM also appear to be more prone to undergoing a second intervention for progressive disease. Hence, a closer follow-up may be warranted in patients who present with multiple lesions. These results show a decreased PFS for each additional lesion present, as well as a shorter PFS for MM compared to a single lesion. When assessing associated risk factors, African American patients showed an inferior PFS, whereas older age and adjuvant therapy with radiation showed an improved PFS.


Risk factors associated with postoperative recurrence in atypical intracranial meningioma

Acta Neurochirurgica (2019) 161:2563–2570

Atypical meningioma (AM) has a high rate of local recurrence after surgery, and the role of adjuvant radiotherapy in AM remains controversial. We analysed progression-free survival (PFS) and identified the factors associated with postoperative recurrence in AM patients.

Methods Data were obtained from 263 AM patients who underwent surgery at our institution between October 2009 and September 2018. Analyses included factors such as the extent of surgical resection, MIB-1 labelling index, brain invasion and therapy modality. Univariate and multivariate analyses were used to assess recurrence-related prognostic factors.

Result The median follow-up duration was 41 months, and the median PFS was 28 months. Gross total resection (GTR) was achieved in 213 (81.0%) patients, and 86 (32.7%) patients received postoperative radiation therapy (RT). During follow-up, there were 61 (23.2%) tumour recurrences. In a Cox multivariate analysis, MIB-1 labelling index (hazard ratio = 2.637; p < 0.001), secondary tumour (hazard ratio = 3.541; p < 0.001), tumour size (hazard ratio = 1.818; p = 0.032) and extent of resection (hazard ratio = 2.861; p < 0.001) were independent significant predictors of tumour recurrence. RTwas associated with reduced tumour recurrence in subtotal resection (STR) (p = 0.023) but not GTR (p = 0.923). An analysis of 6 meningioma patients who underwent more than 3 operations suggested that the recurrence time became shorter and the MIB-1 labelling index increased as the number of recurrences increased.

Conclusions MIB-1 labelling index, secondary tumour, tumour size and extent of resection were powerful predictors of recurrence in AM patients. Postoperative RT did not decrease the risk of recurrence in GTR patients.

Posterior fossa meningiomas: perioperative predictors of extent of resection, overall survival and progression-free survival

Acta Neurochirurgica (2019) 161:1003–1011

Posterior fossa meningiomas (PFMs) often represent surgical challenges due to their proximity to neurovascular structures. Factors predicting the extent of resection (EOR), overall survival (OS), and progression-free survival (PFS) were identified and integrated in a prediction tool to offer evidence-based personalized therapeutic strategies.

Methods All meningiomas managed surgically from 1990 to 2010 from a single-center were reviewed. A classification tree was created using the classification and regression tree recursive partitioning analysis that incorporated patient and tumor data available before surgery in order to predict the rates of gross total resection (GTR).

Results A total of 198 patients were identified (female-to-male ratio, 2.7; mean age, 59.1 years) and compared with 1271 supratentorial meningiomas (STMs) operated in the same institution during the same time period. GTR was achieved less often (59.6% versus 81.9%; p < 0.01) in PFMs than STMs. Preoperative neurological symptoms were predictive of higher Simpson grades (OR, 2.19 [1.05; 4.58]; p = 0.04). Age was associated with reduced OS (OR, 1.08 [1.04;1.12]; p < 0.001). A KPS ≥ 70 was associated with higher survival rates (OR, 2.70 [2.19;2.92]; p = 0.02). Higher WHO grades were associated with reduced OS (OR, 3.56 [1.02;12.47]; p = 0.05). The GTR rate varies from 80% in patients without a preoperative deficit to 40% patients with a preoperative deficit, younger than 60 years old, and with adjacent bone invasion.

Conclusions This study provides a classification tree of the predictors of EOR in PFMs, based upon preoperative demographic, clinical, and radiological variables. An evidence-based management protocol with estimated EORs may guide the decision making process in PFMs.

Volumetric growth rates of meningioma and its correlation with histological diagnosis and clinical outcome

Acta Neurochir (2017) 159:435–445

Tumour growth has been used to successfully predict progression-free survival in low-grade glioma. This systematic review sought to establish the evidence base regarding the correlation of volumetric growth rates with histological diagnosis and potential to predict clinical outcome in patients with meningioma.

Methods This systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Databases were searched for full text English articles analysing volumetric growth rates in patients with a meningioma.

Results Four retrospective cohort studies were accepted, demonstrating limited evidence of significantly different tumour doubling rates and shapes of growth curves between benign and atypical meningiomas. Heterogeneity of patient characteristics and timing of volumetric assessment, both pre- and post-operatively, limited pooled analysis of the data. No studies performed statistical analysis to demonstrate the clinical utility of growth rates in predicting clinical outcome.

Conclusion This systematic review provides limited evidence in support of the use of volumetric growth rates in meningioma to predict histological diagnosis and clinical outcome to guide future monitoring and treatment.

Low-grade Glioma Surgery in Intraoperative Magnetic Resonance Imaging

Hypnosis for Awake Surgery of Low-grade Gliomas

Neurosurgery 78:775–786, 2016

The ideal treatment strategy for low-grade gliomas (LGGs) is a controversial topic. Additionally, only smaller single-center series dealing with the concept of intraoperative magnetic resonance imaging (iMRI) have been published.

OBJECTIVE: To investigate determinants for patient outcome and progression-freesurvival (PFS) after iMRI-guided surgery for LGGs in a multicenter retrospective study initiated by the German Study Group for Intraoperative Magnetic Resonance Imaging.

METHODS: A retrospective consecutive assessment of patients treated for LGGs (World Health Organization grade II) with iMRI-guided resection at 6 neurosurgical centers was performed. Eloquent location, extent of resection, first-line adjuvant treatment, neurophysiological monitoring, awake brain surgery, intraoperative ultrasound, and fieldstrength of iMRI were analyzed, as well as progression-free survival (PFS), new permanent neurological deficits, and complications. Multivariate binary logistic and Cox regression models were calculated to evaluate determinants of PFS, gross total resection (GTR), and adjuvant treatment.

RESULTS: A total of 288 patients met the inclusion criteria. On multivariate analysis, GTR significantly increased PFS (hazard ratio, 0.44; P < .01), whereas “failed” GTR did not differ significantly from intended subtotal-resection. Combined radiochemotherapy as adjuvant therapy was a negative prognostic factor (hazard ratio: 2.84, P < .01). Field strength of iMRI was not associated with PFS. In the binary logistic regression model, use of high-field iMRI (odds ratio: 0.51, P < .01) was positively and eloquent location (odds ratio: 1.99, P < .01) was negatively associated with GTR. GTR was not associated with increased rates of new permanent neurological deficits.

CONCLUSION: GTR was an independent positive prognostic factor for PFS in LGG surgery. Patients with accidentally left tumor remnants showed a similar prognosis compared with patients harboring only partially resectable tumors. Use of high-field iMRI was significantly associated with GTR. However, the field strength of iMRI did not affect PFS.