The study of clinical factors influencing the growth rate of vestibular schwannoma in neurofibromatosis type II

Abstract

Objective To assess the clinical factors influencing the growth rate of neurofibromatosis type 2 (NF2)-related vestibular schwannomas (VSs). Methods The medical records of 66 patients with NF2 treated in Department of Neurosurgery of Beijing Tiantan Hospital from January 2003 to October 2016 were analyzed retrospectively. The tumors were measured by the software of Image J. The tumor growth rate was estimated by linear regression analysis of the changes in VS volumes over time. The clinical characteristics of all patients were documented. The relationship between the tumor growth rate and clinical factors was investigated. Linear regression, Pearson's correlation and t-test were conducted using the SPSS 19.0 statistical package. Results The median follow-up duration was 58.8±10.4 months. The average growth rate was 2.6±1.2 cm3/year. The VS growth rate was positively correlated with the initial volume of VS (r=0.97, P<0.01). However, it was negatively correlated with the age at symptom onset (r=-0.41, P<0.01). The VS growth rate in patients who underwent resection of a contralateral VS was slightly higher than that of patients with untreated VSs (P<0.01). The average VS growth rate in patients with spinal tumors was higher than that in those without spinal tumors. Conclusions The potential clinical factors influencing the VS growth rate include the age at symptom onset, initial tumor volume, resection of contralateral VS and presence of spinal tumors, which could provide reference for clinical treatment. Key words: Neurofibromatosis 2; Neuroma, acoustic; Tumour growth rate