Clinical Question: What are the clinical and radiologic variables associated with recurrence using magnetic resonance imaging (MRI) following vestibular schwannoma (VS) resection?
Background: Although the primary goal of surgery for VS is complete tumor removal, in a subset of patients, adherent tumor remnants may be left behind intentionally to preserve neural integrity. However, there is no consensus regarding an optimal post-operative MRI surveillance schedule.
Explore this issue:February 2012
Study design: Retrospective cohort study.
Setting: Department of Otolaryngology-Head and Neck Surgery, Department of Radiology, Department of Neurologic Surgery and Department of Health Sciences Research, Mayo School of Graduate Medical Education, Rochester, Minn.
Synopsis: Of 350 patients who underwent microsurgical VS resection, 203 met study criteria for the time period of 2000 to 2010. Stable enhancement patterns were seen in 24.5 percent of patients, regression in 66 percent and resolution in 3.5 percent. Those receiving subtotal resection were more than nine times more likely to experience recurrence compared to those undergoing near total or gross total resection. Nodular enhancement on the initial post-operative MRI was associated with a 16-fold increased risk for future recurrence compared with those with linear patterns. Among those with nodular enhancement on baseline post-operative MRI, a maximum linear diameter of > 15 mm or volume of > 0.4 cm was associated with an approximate five-fold increase in risk for future growth.
Bottom line: While MRI enhancement within the post-surgical bed following VS resection is extremely common, making the diagnosis of tumor recurrence difficult, factors such as completeness of resection and baseline post-operative MRI findings provide valuable information regarding risk for recurrence.
Reference: Carlson ML, Van Abel KM, Driscoll CL, et al. Magnetic resonance imaging surveillance following vestibular schwannoma resection. Laryngoscope. 2012;122(2):378-388.