Trends in the Management of Non-Vestibular Skull Base and Intracranial Schwannomas

Carlos Suárez,^1,2 Fernando López,^{1– 3} William M Mendenhall,⁴ Simon Andreasen^{5– 7}†, Lauge Hjorth Mikkelsen,⁷ Johannes A Langendijk,⁸ Stefano Bondi,⁹ Juan P Rodrigo,^{1– 3} Leif Bäck,¹⁰ Antti A Mäkitie,^{10– 12} Verónica Fernández-Alvarez,¹³ Andrés Coca-Pelaz,^{1– 3} Robert Smee,¹⁴ Alessandra Rinaldo,¹⁵ Alfio Ferlito<sup>16

1</sup>Instituto de Investigación Sanitaria del Principado de Asturias and CIBERONC, ISCIII, Oviedo, Spain; ²Instituto Universitario de Oncología del Principado de Asturias, Universidad of Oviedo, Oviedo, Spain; ³Department of Otorhinolaryngology, Hospital Universitario Central de Asturias, Oviedo, Spain; ⁴Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL, USA; ⁵Department of Otorhinolaryngology Head and Neck Surgery and Audiology, Rigshospitalet, Copenhagen, Denmark; ⁶Department of Otorhinolaryngology and Maxillofacial Surgery, Zealand University Hospital, Køge, Denmark; ⁷Department of Pathology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark; ⁸Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands; ⁹Department of Otorhinolaryngology-Head and Neck Surgery, San Raffaele Hospital, Vita-Salute University, Milan, Italy; ¹⁰Department of Otorhinolaryngology - Head and Neck Surgery, University of Helsinki, Helsinki University Hospital, Helsinki, Finland; ¹¹Research Program in Systems Oncology, Faculty of Medicine, University of Helsinki, Helsinki, Finland; ¹²Division of Ear, Nose and Throat Diseases, Department of Clinical Sciences, Intervention and Technology, Karolinska Institute, Karolinska Hospital, Stockholm, Sweden; ¹³Vascular Surgery Department, Hospital Universitario Central de Asturias, Oviedo, Spain; ¹⁴Department of Radiation Oncology, The Prince of Wales Cancer Centre, Sydney, NSW, Australia; ¹⁵University of Udine School of Medicine, Udine, Italy; ¹⁶International Head and Neck Scientific Group, Padua, Italy

†Simon Andreasen passed away on February 28, 2020

Correspondence: Carlos Suárez
Instituto de Investigación Sanitaria del Principado de Asturias and CIBERONC, ISCIII, Avenida de Roma s/n, Oviedo 33011, Spain
Email csuareznieto@gmail.com
Fernando López
Department of Otorhinolaryngology, Hospital Universitario Central de Asturias, Avenida de Roma s/n, Oviedo 33011, Spain
Email flopez_1981@yahoo.es

Abstract: The aim of this review is to analyze the latest trends in the management of non-vestibular skull base and intracranial schwannomas in order to optimize tumor control and quality of life. Non-vestibular cranial nerve schwannomas are rare lesions, representing 5– 10% of cranial nerve schwannomas. Management decisions should be individualized depending on tumor size, location and associated functional deficits. Generally, large sized schwannomas exerting significant mass effect with increased intracranial pressure are treated surgically. In some cases, even after optimal skull base resection, it is not possible to achieve a gross total resection because tumor location and extent and/or to reduce morbidity. Thus, subtotal resection followed by stereotactic radiosurgery or fractioned radiotherapy offers an alternative approach. In certain cases, stereotactic radiosurgery or radiotherapy alone achieves good tumor control rates and less morbidity to gross total resection. Finally, given the slow growth rate of most of these tumors, observation with periodic radiographic follow-up approach is also a reasonable alternative for small tumors with few, if any, symptoms.

Keywords: schwannoma, head and neck, cranial nerves, non-vestibular, skull base