NF2 leads bilateral VS, which cause high rates of deafness by mid-adulthood. Conventional treatments, like radiotherapy and surgery, carry high risks including facial and auditory nerve damage. Bevacizumab, a non-invasive treatment, protects hearing, but its impact on quality of life and expanded audiological parameters remains unknown. In 2022, our Neurofibromatosis Expertise Center introduced a standardized protocol for disease surveillance and bevacizumab administration.

This is a retrospective descriptive study including patients with NF2 and divided into three groups: Group 1, treated with bevacizumab prior to 2022; Group 2, monitored since 2022 but without treatment indication; and Group 3, treated with bevacizumab since 2022. For each group, audiology parameters, tumor volume, and quality of life were measured and followed over time. 

22 patients were included: 5 in group 1, 12 in group 2, and 5 in group 3. 12 symptomatic ears were treated with bevacizumab: 6 in group 1 and 6 in group 3. 4 ears were free from further hearing loss in group 3 after a median treatment duration of 6 months as opposed to 2 ears in group 1 after a median treatment duration of 96 months.  Median SV volume at treatment initiation was 23.5 mL in group 1, and 8.8mL in group 3. The median total score at the SSQ-12 was 2.5 at treatment initiation in group 3. 

More patients were free of hearing loss and their VS were smaller in sizes at treatment initiation in the group with a standardized surveillance and treatment protocol than in the group prior to its introduction. Prior to bevacizumab initiation, patients have low scores in the SSQ-12.