Surgical Management of Craniospinal Axis Solitary Fibrous Tumors

Neurosurgery 94:358–368, 2024

Meningeal solitary fibrous tumors (SFTs) comprise 0.4% of primary central nervous system neoplasms and carry metastatic potential. Disease course and optimal management are largely unknown, and there is currently no literature rigorously describing neurological outcomes in surgically managed SFTs. We present one of the largest craniospinal SFT series, analyze patient outcomes, and extensively review the associated literature.

METHODS: All surgically managed SFTs at our institution between January 2005 and March 2023 were retrospectively reviewed. Patient demographics, tumor and radiographic features, treatment, and clinical outcomes were collected. Neurological function was quantified using Frankel grade and Neurologic Assessment in NeuroOncology scores. Descriptive statistics, multivariate analysis, log-rank test, and Kaplan–Meier survival analysis were performed.

RESULTS: Twenty-one patients satisfied inclusion criteria. Tumor locations included 15 supratentorial, three infratentorial, and three spinal. All patients underwent surgical resection, and 16 (76.2%) underwent radiation. Six (28.6%) patients had tumor recurrence, and three (14.3%) developed metastasis. Younger age and higher postoperative Frankel grade were significantly associated with increased overall survival (OS) (P = .011, P = .002, respectively). All patients symptomatically improved or stabilized after surgery, and Neurologic Assessment in Neuro-Oncology score (P = .001) and functional status significantly improved postoperatively (Karnofsky Performance Status: 65.2 ± 25.2 vs 91.4 ± 13.5, P = .001). Sex, adjuvant radiation, and extent of resection were not significantly associated with OS.

CONCLUSION: SFT of the central nervous system is a rare entity with a variable clinical course. Surgical resection was associated with improved postoperative functional and neurological status. Higher postoperative neurological function was significantly associated with OS. Further studies are warranted to validate a standardized treatment algorithm and investigate the efficacy of adjuvant radiation in SFT.

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.

Extradural disconnection of the cavernous sinus with preservation of the internal carotid artery: indication and technique

Acta Neurochirurgica (2023) 165:2951–2956

Extradural disconnection of the cavernous sinus (CS) with preservation of the internal carotid artery (ICA) is indicated for aggressive and recurrent tumors, in patients presenting loss of oculomotor function and non-functional circle of Willis.

Method Extradural resection of the anterior clinoid process disconnects the CS anteriorly. The ICA is dissected in the foramen lacerum via extradural subtemporal approach. The intracavernous tumor is split and removed following the ICA. Bleeding control of the inferior and superior petrosal and intercavernous sinuses completes posterior CS disconnection.

Conclusion This technique can be proposed for recurrent CS tumors and need of ICA preservation.

Radiological Differentiation Between Intracranial Meningioma and Solitary Fibrous Tumor/Hemangiopericytoma

World Neurosurg. (2023) 170:68-83

Intracranial solitary fibrous tumor (SFT) is characterized by aggressive local behavior and high post-resection recurrence rates. It is difficult to distinguish between SFT and meningiomas, which are typically benign. The goal of this study was to systematically review radiological features that differentiate meningioma and SFT.

METHODS: We performed a systematic review in accordance with PRISMA guidelines to identify studies that used imaging techniques to identify radiological differentiators of SFT and meningioma.

RESULTS: Eighteen studies with 1565 patients (SFT: 662; meningiomas: 903) were included. The most commonly used imaging modality was diffusion weighted imaging, which was reported in 11 studies. Eight studies used a combination of diffusion weighted imaging and T1- and T2-weighted sequences to distinguish between SFT and meningioma. Compared to all grades/subtypes of meningioma, SFT is associated with higher apparent diffusion coefficient, presence of narrow-based dural attachments, lack of dural tail, less peritumoral brain edema, extensive serpentine flow voids, and younger age at initial diagnosis. Tumor volume was a poor differentiator of SFT and meningioma, and overall, there were less consensus findings in studies exclusively comparing angiomatous meningiomas and SFT.

CONCLUSIONS: Clinicians can differentiate SFT from meningiomas on preoperative imaging by looking for higher apparent diffusion coefficient, lack of dural tail/narrow-based dural attachment, less peritumoral brain edema, and vascular flow voids on neuroimaging, in addition to younger age at diagnosis. Distinguishing between angiomatous meningioma and SFT is much more challenging, as both are highly vascular pathologies. Tumor volume has limited utility in differentiating between SFT and various grades/subtypes of meningioma.