Growth characteristics of vestibular schwannomas.
OBJECTIVE
To assess the growth characteristics of small- to medium-sized vestibular schwannomas in patients undergoing watch, wait, and rescan management.


METHODS
Cohort study using prospectively collected size and tumor morphology data.


METHODS
Tertiary referral center for cranial base surgery.


METHODS
Three hundred eighty-one patients with sporadic unilateral vestibular schwannomas and 2 or more magnetic resonance scans were included. Linear measurements were used to assess tumor size. The point of growth and pattern of growth progression were assessed. Factors influencing growth were investigated.


RESULTS
Approximately 33% of tumors demonstrated significant growth. Mean size at presentation was 9.9 mm (standard deviation [SD]. 4.8). For growing tumors, mean size at final review was 13.7 mm (SD, 4.8). This was a statistically significant increase in size (p < 0.0001). Mean annual change in size for growing tumors was 2.3 mm (SD, 2.3). 52.4% of growing tumors showed radiologically demonstrable first growth within 18 months of presentation. Approximately 7.2% of tumors showed radiologically demonstrable first growth after 5 years of follow-up. There were no demographic or morphologic predictors of growth.


CONCLUSIONS
Tumor growth is usually slow and is most likely to occur within the first 3 years of observation. Growth may occur after five years of follow-up. A protocol for the scanning of patients is suggested based on the findings of the study.
Cambridge University Teaching Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Cambridge, UK.
David A
DA
Moffat
Anand
A
Kasbekar
Patrick R
PR
Axon
Simon K W
SK
Lloyd
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D016208:Databases, Factual; D018450:Disease Progression; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000473:pathology*; D011446:Prospective Studies; D016019:Survival Analysis; D057832:Watchful Waiting