J Neurol Surg B Skull Base 2018; 79(S 01): S1-S188
DOI: 10.1055/s-0038-1633819
Poster Presentations
Georg Thieme Verlag KG Stuttgart · New York

Long-Term Effects of Bevacizumab on Vestibular Schwannoma Volume in Neurofibromatosis Type 2 Patients: The UT Southwestern Experience

Daniel E. Killeen
1   Department of Otolaryngology – Head and Neck Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, United States
,
Laura Klesse
2   Departments of Pediatrics and Neurosurgery, University of Texas Southwestern Medical Center, Dallas, Texas, United States
,
Anthony M. Tolisano
1   Department of Otolaryngology – Head and Neck Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, United States
,
Jacob B. Hunter
1   Department of Otolaryngology – Head and Neck Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, United States
,
Joe Walter Kutz
1   Department of Otolaryngology – Head and Neck Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, United States
› Author Affiliations
Further Information

Publication History

Publication Date:
02 February 2018 (online)

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Background Bevacizumab offers the potential of a medical treatment that may slow growth and progression of vestibular schwannomas with possible hearing preservation in neurofibromatosis type 2. This study aims to investigate the effect of long-term bevacizumab treatment on vestibular schwannoma progression and hearing.

Methods In this retrospective chart review, audiometric, radiographic, demographic, and clinical data were collected from the medical records of all neurofibromatosis type 2 patients treated with bevacizumab at a tertiary medical center. Statistical analysis included Whitney–Mann’s U test and Cox’s regression.

Results Eleven tumors from seven subjects with neurofibromatosis type 2 treated with bevacizumab were analyzed. The median age was 17 years (range: 12–47). Median bevacizumab treatment time was 33 months (range: 12–74). Complications of bevacizumab treatment included fatigue (three out of seven, 43%), nausea/vomiting (three out of seven, 43%), epistaxis (two out of seven, 29%), proteinuria (two out of seven, 29%), irregular menstrual cycle (two out of seven, 28%), mucositis (one out of seven, 14%), conjunctivitis (one out of seven, 14%), and diarrhea (one out of seven, 14%). One subject had a cerebrovascular accident detected on screening MRI without symptoms or neurological sequelae. Median change in pure tone average for hearing during bevacizumab treatment was 15 dB (range: −4.4–50). Change in tumor volume during bevacizumab treatment (median: 0.1 cm3/y, range: −0.92–0.41) was significantly smaller (p = 0.0263) than the change in volume of these tumors without bevacizumab (median: 1.38 cm3/y, range: 0.013–3.74). There was reduced tumor progression during bevacizumab treatment based on either linear greatest diameter (hazard ratio: 0.16, p = 0.006) or volume (hazard ratio: 0.15, p = 0.023).

Discussion These results suggest that bevacizumab may reduce tumor growth rate and the risk of progression based on either volumetric or linear measurements.