COMPLICATIONS FROM ARTERIOVENOUS MALFORMATION RADIOSURGERY - MULTIVARIATE-ANALYSIS AND RISK MODELING

Purpose/Objective: To assess the relationships of radiosurgery treatme nt parameters to the development of complications from radiosurgery fo r arteriovenous malformations (AVM). Methods and Materials: We evaluat ed follow-up imaging and clinical data in 307 AVM patients who receive d gamma knife radiosurgery at the University of Pittsburgh between 198 7 and 1993, All patients had regular clinical or imaging follow up for a minimum of 2 years (range: 24-96 months, median = 44 months). Resul ts: Post-radiosurgical imaging (PRI) changes developed in 30.5% of pat ients with regular follow-up magnetic resonance imaging, and were symp tomatic in 10.7% of all patients at 7 years, PRI changes resolved with in 3 years developed significantly less often (p = 0.0274) in patients with symptoms (52.8%) compared to asymptomatic patients (94.8%), The 7-year actuarial rate for developing persistent symptomatic PRI change s was 5.05%. Multivariate logistic regression modeling found that the 12 Gy volume was the only independent variable that correlated signifi cantly with PRI changes (p < 0.0001) while symptomatic PRI changes wer e correlated with both 12 Gy volume (p = 0.0013) and AVM location (p = 0.0066). Conclusion: Complications from AVM radiosurgery can be predi cted with a statistical model relating the risks of developing symptom atic post-radiosurgical imaging changes to 12 Gy treatment volume and location. (C) 1997 Elsevier Science Inc.