Acoustic neuroma: What the evidence says about evaluation and treatment
Tumor size and a patient’s age, condition, and personal preference are key factors in choosing among watchful waiting, microsurgery, or stereotactic radiosurgery.
Based on these limited studies, patient-oriented outcomes can be comparable between stereotactic radiosurgery and micro-surgery in medium-sized tumors (1-2.9 cm), depending on the patient’s clinical presentation. Hearing and preservation of nerve VII are more likely with radiosurgery than with microsurgery. But several real and potentially large confounding factors limit this interpretation. How does one define tumor control in light of AN’s inherently slow growth? What about reports of less than optimal microsurgery outcomes if previous radiosurgery has failed? And, although it is small, a definite risk of malignant transformation exists after irradiation.8,13
For patients to make good decisions, family physicians need to be aware of these issues when discussing treatment options. To aid in patient education and decision making, there is a helpful algorithm from the International RadioSurgery Association in Stereotactic radiosurgery for patients with vestibular schwannomas (available online at https://www.irsa.org/ANGuideline.pdf).15
Follow-up
Follow-up depends on the treatment modality, but usually relies on MRI to document tumor behavior. MRI studies are typically performed at predetermined intervals such as 6 months and 1, 2, and 4 years. For patients with preserved serviceable hearing, audiograms are recommended at intervals coinciding with clinical and neuroimaging re-evaluations. Tumors proven to be stable over 4 to 5 years can subsequently be reassessed at 2- to 4-year intervals.15
Enabling recovery. One of the most important educational opportunities involves early vestibular rehabilitation to facilitate recovery of postural control after treatment. Research has shown benefit from customized vestibular rehabilitation in addition to instructions that stress the need to engage in some type of activity, such as walking or other modes of exercise.22
CORRESPONDENCE
Robert McDonald, MD, Spartanburg Family Medicine Residency Program, 853 N. Church Street, Suite 510, Spartanburg, SC 29303; rmcdonald@srhs.com
