Stereotactic radiation therapy for treatment of canine intracranial meningiomas.

The objective of this study is to determine the rate of toxicity, median survival time (MST) and prognostic factors in dogs with presumed intracranial meningiomas that were treated with stereotactic radiation therapy (SRT). Patient demographics, neurological history, details of SRT plans and response to treatment (including toxicity and survival times) were examined for potential prognostic factors. Overall MST (MST) due to death for any cause was 561 days. There was a mild to moderate exacerbation of neurological symptoms 3-16 weeks following SRT treatments in 11/30 (36.7%) of dogs. This presumed adverse event was treated with corticosteroids, and improvement was seen in most of these dogs. Death within 6 months of treatment as a result of worsening neurologic signs was seen in 4/30 (13.3%) of dogs. Volume of normal brain that received full dose at a prescription of 8Gy × 3 fractions was predictive of death due to neurological problems within this 6-month period.