Clinical Parameters and Radiomics of Vestibular Schwannomas in NF2-related Schwannomatosis

NF2-related schwannomatosis is a rare hereditary tumor predisposition syndrome, formerly known as Neurofibromatosis type 2 (NF2), and is characterized by the development of multiple schwannomas. The hallmark manifestation is the occurrence of bilateral vestibular schwannomas (VSs). Disease progression and clinical outcomes vary widely among patients, and conventional magnetic resonance imaging (MRI) metrics-such as tumor size-do not fully account for these differences. Radiomic analysis offers a quantitative approach to extract advanced imaging biomarkers that may capture tumor microstructure and growth behavior more accurately, potentially improving prognostication and individualized management in NF2.

A retrospective cohort of 32 patients with NF2 was analyzed, comprising 170 cranial MRI scans of 232 VSs (112 left, 120 right) acquired at different time points over the course of disease, with previously treated tumors excluded. Tumor growth was quantified as absolute and percentage growth rates per month. Radiomic features were extracted from segmented tumors and correlated with Common Terminology Criteria for Adverse Events (CTCAE) graded clinical findings. Hearing impairment was graded based on subjective function due to limited audiometric data.

In this exploratory analysis, no Spearman |ρ| >0.40 correlations were observed between radiomics features and tumor growth rates, nor among clinical parameters (excluding depression and anxiety). Right-sided tumors were associated with significantly greater hearing impairment compared to left-sided tumors despite comparable volumes (p=0.030). Age-stratified analyses revealed distinct patterns: in younger patients (<30 years), fast-growing tumors displayed more homogeneous texture profiles, while in older patients (>30 years), rapid growth was linked to greater heterogeneity.

Radiomic profiling indicates that both tumor laterality and patient age influence the relationship between imaging features and clinical outcomes in NF2-associated VS. Homogeneity was linked to aggressive growth in younger patients, heterogeneity characterized progression in older patients. These findings suggest that radiomic biomarkers may complement volumetric measures and support individualized monitoring and treatment strategies in NF2.