Conservative Management of Small Acoustic Neuromas: Compliance Rates and Outcomes Over 5 Years at a Single Institution

Objectives (1) Evaluate rate of compliance and outcomes over 5.5 years for patients opting to undergo serial imaging and observation for management of a small acoustic neuroma (< 2 cm). (2) Identify predictive factors that may influence follow-up compliance, including distance from imaging center, patient age, and patient comorbidities.

Methods All patients diagnosed with an acoustic neuroma between the years 2006 and 2016 were identified using CPT codes. Patients who underwent stereotactic radiosurgery or surgical resection were excluded from the study (n = 300). Magnetic resonance imaging was used to determine the size of tumor and growth rate at each follow-up visit. Outcomes measured included number of follow-up visits, tumor growth rate, symptom progression, hearing outcomes, as well as number of patients who failed conservative management (and went on to surgical or stereotactic radiosurgery).

Results A total of 189 patients were included in this study (87 females, 102 males). Mean age at diagnosis was 59.7 years. Five patients (2.6%) had a diagnosis of neurofibromatosis-2 (NF-2). The average number of follow-up visits in 5.5 years was 2.2. We intend to evaluate symptoms progression and tumor growth rate. We will also use a predictive model to identify any factors that could negatively or positively influence follow-up compliance rates as well as the number of patients who fail conservative management and go on to interventional treatment.

Conclusion The compliance rate for follow-up in patients opting to undergo serial imaging and observation for small acoustic neuromas is very low. We hypothesize that geographical proximity to the imaging center, comorbidities, and age are factors that can affect compliance rates in this patient population.