1. From the Departments of Pathology (Drs Evans and Bilbao) and Neurosurgery (Drs Fayaz and Cusimano), St. Michael's Hospital, and Department of Radiation Oncology, Princess Margaret Hospital (Dr Laperriere), University of Toronto, Toronto, Ontario.
2. Reprints: Juan M. Bilbao, MD, Department of Pathology, St. Michael's Hospital, 30 Bond St, Toronto, Ontario, Canada M5B 1W8 (bilbaoj@smh.toronto.on.ca).