Background: There has been no report of a detailed long-term study of hearing at defined frequencies.
Aims/objectives: This study aimed to evaluate long-term vestibular shwannoma (VS) growth and long-term changes in hearing thresholds at defined frequencies.
Methods: We retrospectively retrieved the medical records of 67 VS patients. Cases that were followed up for more than 5 years were analyzed.
Results: Tumor growth was observed in 15 cases (22.4%) and 6 cases underwent gamma knife treatment (9.0%). The longest case of tumor growth and gamma knife treatment was observed 11 years after the initial diagnosis. Hearing thresholds at 500-2000 Hz was significantly different between the no growth and growth group (p < .05). Particularly at 1000 Hz, there was a significant difference between the two groups from an early time-point.
Conclusions and significance: Even a 10-year or longer follow-up of VS may show an increase in tumor growth. Moreover, hearing thresholds, particularly at 1000 kHz, may predict tumor growth when following-up VS patients.
Keywords: Acoustic neuroma; gamma knife; hearing threshold; magnetic resonance imaging; wait-and-scan.