1. Department of Surgery , Division of Thoracic Surgery, Queen Elizabeth II Health Sciences Centre, , Halifax, Nova Scotia, Canada
2. Dalhousie University , Division of Thoracic Surgery, Queen Elizabeth II Health Sciences Centre, , Halifax, Nova Scotia, Canada
3. Department of Surgery , Division of Neurosurgery, Queen Elizabeth II Health Sciences Centre, , Halifax, Nova Scotia, Canada
4. Dalhousie University , Division of Neurosurgery, Queen Elizabeth II Health Sciences Centre, , Halifax, Nova Scotia, Canada
5. Department of Pathology , Queen Elizabeth II Health Sciences Centre, , Halifax, Nova Scotia, Canada
6. Dalhousie University , Queen Elizabeth II Health Sciences Centre, , Halifax, Nova Scotia, Canada