title: Stereotactic Radiosurgery versus Natural History in Patients with Growing Vestibular Schwannomas.
abstract: Objective To describe our experience with stereotactic radiosurgery and its efficacy on growing tumors, and then to compare this result with the natural history of a similar cohort of non-radiation-treated lesions. Study Design A retrospective chart review and cohort comparison. Methods The long-term control rates of patients having undergone radiosurgery were collected and calculated, and this population was then compared with a group of untreated patients from the same period of time with growing lesions. Results A total of 61 patients with growing vestibular schwannomas treated with radiosurgery were included. After a mean of 160 months, we observed a control rate of 85.2%. When compared with a group of 36 patients with growing tumors who were yet to receive treatment (previously published), we found a corrected control rate or relative risk reduction of only 76.8%. Conclusion Radiosurgery for growing vestibular schwannomas is less effective than previously reported in unselected series. Although radiosurgery still has a role in managing this disease, consideration should be given to the actual efficacy that may be calculated when the natural history is known. We hope other centers will similarly report their experience on this cohort of patients.
authors.affiliation: Division of Neurosurgery, University of British Columbia, British Columbia, Canada.
authors.forename: Albert
authors.initials: A
authors.lastname: Tu
authors.affiliation: Division of Neurosurgery, University of British Columbia, British Columbia, Canada.
authors.forename: Peter
authors.initials: P
authors.lastname: Gooderham
authors.affiliation: Division of Otolaryngology, Kelowna General Hospital, Kelowna, British Columbia, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Mick
authors.affiliation: Division of Otolaryngology, University of British Columbia, British Columbia, Canada.
authors.forename: Brian
authors.initials: B
authors.lastname: Westerberg
authors.affiliation: Division of Neurosurgery, University of British Columbia, British Columbia, Canada.
authors.forename: Brian
authors.initials: B
authors.lastname: Toyota
authors.affiliation: Division of Neurosurgery, University of British Columbia, British Columbia, Canada.
authors.forename: Ryojo
authors.initials: R
authors.lastname: Akagami
keywords: control rates; growing tumors; natural history; radiosurgery; vestibular schwannomas