Integrating 3D Rotational Angiography into Gamma Knife Planning

A 34-year-old woman with an unruptured, small, left medial frontal arteriovenous malformation, once treated with gamma knife (A). The small remnant nidus persisted at 3.5 years from the initial radiosurgery (B, a red arrowhead shows the remnant nidus). The actual treatment planning of the secondary treatment (C) shows that 3D rotational angiography (left column) successfully depicts the faint remnant, while both time-of-flight (middle column) and gadolinium-enhanced T1 images (right column) fail to depict it. The nidus was finally obliterated (D) at 1.5 years from the secondary treatment. Yellow lines show the prescription isodose lines.