Professor John Armstrong
- Consultant Radiation Oncologist
- Fellow Royal College of Physicians of Ireland
- Fellow of the Faculty of Radiology – Royal College of Surgeons in Ireland
- Member of American Society of Clinical Oncology
- Member of Amercian Society of Therapeutic Radiology and Oncology
- Member of American Endocurietherapy Society
- Member of Royal Academy of Medicine in Ireland
- Member of International Association for the study of Lung Cancer
- Founding member and ex - President of the following:
- Irish Clinical Oncology Research Group
- The European Organization for the Research and Treatment of Cancer
- The European Society of Therapeutic Radiology and Oncology