Vestibular schwannomas with spontaneous shrinkage: about 35 cases

• Published in: European archives of oto-rhino-laryngology Vol. 278; no. 11; pp. 4235 - 4241
• Main Authors: Trau, Guillaume, Venkatasamy, Aïna, Charpiot, Anne
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-11-2021; Springer Verlag
• Subjects: Head and Neck Surgery; Mechanics; Medicine; Medicine & Public Health; Neurosurgery; Otology; Otorhinolaryngology; Physics; Regression; Volumetric analysis; Spontaneous shrinkage; Magnetic resonance imaging; Acoustic neuroma; Vestibular schwannoma
• ISSN: 0937-4477; 1434-4726
• DOI: 10.1007/s00405-020-06530-6

Purposes
The first aim is to describe the epidemiological, clinical, and radiological characteristics of regressive vestibular schwannomas (VS), based on volumetric measurements on MRI to define which regressions are significant. The secondary aim is to look for a correlation between a shrinkage of the tumor and the medical history, and the presence of clinical symptoms.
Methods
We first selected all patients presenting with a VS who underwent two or more MRI of the internal auditory canal on the same 3 T MRI machine retrospectively between January 2013 and June 2018. All MRI images were evaluated independently by two radiologists. The volumetric analysis was performed contrast-enhanced 2D spin-echo T1-weighted sequence and expressed in cubic centimeters.
Results
Thirty-five patients presented with a regressive VS on MRI (14%). The annual mean shrinkage rate was 0.08 cm
3
/year. Eighty percent of the patients present both a shrinkage by more than 0.01 cm
3
/year and a decrease of the initial tumor volume by more than 20%. The majority of patients are asymptomatic or presented moderate balance disorders, which remained stable or improved over time. Tinnitus was observed in 47% and was stable or improved in the majority of cases and the mean annual mean hearing loss was by < or = 4 dB/year.
Conclusion
Out of 247 VS, 14% decreased using follow-up (by > or = 2 MRI), and a spontaneous shrinkage greater than 0.01 cm
3
/year and greater than 20% could be considered significant.