Cerebral arteriovenous malformations: the value of radiologic parameters in predicting response to radiosurgery.

PURPOSE To define the morphological patterns of cerebral arteriovenous malformations (AVMs) that influence their response to radiosurgery at 2 years.

METHODS We retrospectively reviewed the yearly MR and angiographic follow-up studies in 102 patients who had radiosurgical treatment for cerebral AVMs between 1990 and 1992. Parameters studied were maximum length and volume of the nidus, position relative to the midline, anatomic structures involved, sectional anatomic location (depth within the brain tissue), angioarchitecture, and Spetzler and Martin grading. Statistical analysis determined their influence on treatment results at 2 years.

RESULTS Parameters that correlated with obliteration at 2 years were maximum length less than 25 mm, small volume, sectional location deep within brain tissue, and plexiform angioarchitecture. Ventricular and paraventricular locations correlated with nonobliteration at 2 years.

CONCLUSION This study highlights the role of two new morphological parameters in predicting the efficiency of radiosurgery in the treatment of cerebral AVMs: depth within the parenchyma and angioarchitecture. It also emphasizes the usefulness of sectional imaging in the work-up before radiosurgery.