Multimodality management of cavernous sinus meningiomas with less extensive surgery followed by subsequent irradiation: Implications for an improved toxicity profile

Citation: Sager O, Beyzadeoglu M, Dincoglan F, Demiral S, Gamsiz H, et al. (2020) Multimodality management of cavernous sinus meningiomas with less extensive surgery followed by subsequent irradiation: Implications for an improved toxicity profile. J Surg Surgical Res 6(1): 056-061. DOI: https://dx.doi.org/10.17352/2455-2968.000098 https://dx.doi.org/10.17352/jssr DOI: 2455-2968 ISSN: C L IN IC A L G R O U P


Introduction
Meningiomas comprise the most frequent intracranial benign tumors accounting for approximately one third of all intracranial neoplasms, and generally follow an indolent disease course with a typically benign nature and slow-growing behaviour [1][2][3][4][5]. Incidence of meningiomas demonstrates an age dependency with the highest incidence in the elderly age group [4,5]. These dural based tumors are considered to arise from the arachnoid meningothelial cells due to unknown etiology, although exposure to ionizing radiation and background of neurofi bromatosis type 2 have been suggested to be in association with meningiomas [3].
Three World Health Organization (WHO) grades with 15 histological subtypes have been included in the WHO classifi cation scheme which underscores the heterogeneity in clinical and molecular characteristics of meningiomas [1,3,6].

Abstract
Meningiomas comprise the most frequent intracranial benign tumors accounting for approximately one third of all intracranial neoplasms, and generally follow an indolent disease course with a typically benign nature and slow-growing behaviour. Although majority of meningiomas may follow an indolent disease course, affected patients may suffer from a plethora of symptoms with regard to lesion location. Symptoms typically occur as a result of the mass effect leading to compression of critical neurovascular structures. Headache, focal seizures, weakness in the limbs, visual disturbances, loss of smell, impaired memory or hearing functions may be observed. Advances in neurosurgery may allow for an improved toxicity profi le following surgical resection as the traditional and a leading mode of management for meningiomas located at accessible brain areas. Nevertheless, vigilance is required given the morbidity and mortality risks associated with meningioma surgery particularly for elderly patients. In this context, radiation therapy (RT) may offer a viable alternative or adjunctive modality of management for meningiomas. Management of cavernous sinus meningiomas in intricate association with critical neurovascular structures pose a formidable challenge to the treating physicians. Attempting at extensive surgical procedures may be associated with substantial morbidity and even mortality. In this context, selected patients may benefi t from a tailored multimodality approach including less extensive surgical resection followed by subsequent irradiation. Primary advantages of this refi ned therapeutic strategy may include improved toxicity profi le along with improved functionality and quality of life. Herein, we assess multimodality management of cavernous sinus meningiomas with less extensive surgery followed by subsequent irradiation.
The most prevalent type includes grade 1 meningiomas as per the WHO classifi cation [6]. Nevertheless, meningiomas of higher WHO grades are typically associated with higher recurrence rates and lower survival durations [3]. Also, a preponderance for frequent relapses, malignant transformation an deven metastases may be of concern although not typical [3].
Diverse localization throughout the central nervous system (CNS) may be seen, nevertheless, the most frequent location for meningiomas includes the supratentorial region, followed by skull base and the posterior fossa [7]. Parasagittal meningiomas, parafalcine meningiomas, convexity meningiomas and intraventricular meningiomas are located at the supratentorial brain whereas sphenoid ridge meningiomas, tuberculum sellae meningiomas, olfactory groove meningiomas, petroclival meningiomas, cavernous sinus meningiomas, and intraorbital meningiomas are located at the skull base region, and jugular foramen meningiomas, peritorcular meningiomas. cerebellopontine angle meningiomas, and cerebellar convexity meningiomas are included in the group of posterior fossa meningiomas [7].
Principal imaging modality for meningiomas is magnetic resonance imaging (MRI). However, computed tomography (CT) imaging may have a role in detection of tumoral calcifi cations, bony changes such as hyperostosis or osteolysis, and intraosseous tumor growth and pneumosinus dilatans especially for skull base lesions [8,9]. Diagnostic features suggestive of meningioma may be present on CT imaging in a considerable proportion of the patients as a lobular and circumscribed lesion with dural attachment [8,9]. Visualization is typically homogeneous on unhanced CT as a hyperdense extraaxial lesion with homogeneous contrast enhancement after administration of the contrast media [8,9]. MRI may be used in detection of the dural tail in some patients visualized as a post-contrast linear thickening of the duramater close to the lesion. Meningiomas are typically visualized as hypointense or isointense lesions on T1-weighted MRI and as hyperintense lesions on T2-weighted MRI usually with well defi ned borders [8,9]. While areas of calcifi cation or necrosis may not demonstrate enhancement, homogeneous contrast enhancement is typical on MRI, and MRI may provide improved contrast differentiation to be utilized for differentiation of intraaxial and extraaxial meningioma lesions. Presence of dural tail may be suggestive of reactive dural changes whereas dural tails may also be infi ltrated by the tumor in some cases.
While not specifi c to meningiomas only, presence of the dural tail may facilitate differentiation of some meningioma lesions from other tumors not exhibiting dural tail such as pituitary adenomas or schwannomas [8,9].
Incidental detection may account for a considerable proportion of newly diagnosed meningiomas thanks to increased availability and use of modernized diagnostic imaging modalities [10][11][12]. Nevertheless, affected meningioma patients may also present with a plethora of symptoms with regard to lesion location. Symptoms typically occur as a result of the mass effect leading to compression of critical neurovascular structures. Headache, focal seizures, weakness in the limbs, visual disturbances, loss of smell, impaired memory or hearing functions may be observed.
Active surveillance by use of periodical neurological assessment with incorporation of advanced neuroimaging techniques may be an option for selected patients given the non-negligible risk of morbidity and quality of life impairment following treatment of particularly incidental intracranial meningiomas [10][11][12][13][14][15]. In the context of cavernous sinus meningiomas, understanding of the natural history may play an integral role in decision making for management. However, limited data exist in the literature regarding the natural history of cavernous sinus meningiomas [16]. Growth of meningiomas within the cavernous sinus has been a less addressed issue, and series of radiation treatment typically focused on tumor growth under therapy without a control group of untreated cavernous sinüs meningiomas. In the comprehensive study by Amelot et al. focusing on this less addressed perspective, the evolution of cavernous sinus meningiomas were reported as unpredictable and irregular [16]. In contrast with meningiomas at other locations, modelling of growth rate profi les may be challenging for cavernous sinus meningiomas [16]. While some lesions may remain indolent for longer periods, gradual upsizing or abrupt manifestation with rapid progression may occur. It appears that thorough neuroimaging follow up is an indispensable component of conservative management of cavernous sinus meningiomas given the unpredictable natural history in a considerable proportion of lesions. Nevertheless, advances in neurosurgery may allow for an improved toxicity profi le following surgical resection as the traditional and a leading mode of management for meningiomas located at accessible brain areas. Nevertheless, vigilance is required given the morbidity and mortality risks associated with meningioma surgery particularly for elderly patients [15,[17][18][19]. Specifi c complications of surgery may include venous bleeding, intratumoral hemorrhages, damage to vital neurovascular structures such as the internal carotid artery, oculomotor nerve or the trigeminal nerve [16].
In this context, radiation therapy (RT) with conventional fractionation of radiosurgery delivered in a single or few treatment fractions may offer a viable alternative or adjunctive modality of management for meningiomas. Herein, we assess multimodality management of cavernous sinus meningiomas with less extensive surgery followed by subsequent irradiation.