St. Luke's Hospital, Rathgar

Professor Sinéad Brennan serves as the National Lead of IRROG and has been a Consultant Radiation Oncologist at St. Luke’s Radiation Oncology Network (SLRON) and St. James’s Hospital since 2010. She is also a Clinical Associate Professor at Trinity College Dublin, with a clinical and academic focus on head and neck and breast cancers.

Professor Brennan plays a central role in the design, delivery, and governance of radiotherapy research in Ireland. She is a senior leader within Cancer Trials Ireland, serving on both the Executive Committee and Senior Management Group, and chairs the Irish Head and Neck Cancer Disease Subgroup. She has also been a Director on the Board of the Irish Cancer Society from 2016 to 2025, and is an active faculty member of the Radiology and Radiation Oncology Committee at the Royal College of Surgeons in Ireland.

Dr. Brendan McClean is the Director of Physics at the St. Luke’s Radiation Oncology Network (SLRON) in Dublin and has dedicated his career to advancing cancer treatment through innovation, research, and education.

After earning a BSc and PhD in Physics from Queen’s University Belfast, he completed postdoctoral research in medical physics at the University of Alberta in Canada. He went on to work as a Senior Radiotherapy Physicist at the Cross Cancer Institute in Edmonton before returning to Ireland in 1995 to take up his current leadership role at SLRON.

Brendan plays a key role in shaping radiotherapy research in Ireland. He is the Physics Lead for the National Cancer Control Programme, Chair of the SLRON Research Ethics Committee, and a Board Member of the St. Luke’s Institute of Cancer Research. He also oversees the Michael Moriarty Research Laboratory Scientific Committee, helping to ensure that research is carried out to the highest ethical and scientific standards.

Professor Brian O’Neill is the IRROG Site Lead at the St. Luke’s Centre in Beaumont Hospital, where he has served as a Consultant Radiation Oncologist with the St. Luke’s Radiation Oncology Network (SLRON) since 2008. He is deeply involved in shaping national policy and clinical guidelines, and is a key voice in strategic research and ethics governance in Ireland.

Professor O’Neill is the Chair of the National Cancer Control Programme’s (NCCP) Radiation Oncology Subgroups for both Prostate and Gastrointestinal Cancers, setting national standards for radiotherapy treatment and research. He is also a Board Member of the St. Luke’s Cancer Research Fund and the St. Luke’s Institute of Cancer Research, and contributes as a faculty member of the Royal College of Surgeons in Ireland.

Professor John Armstrong is the IRROG Site Lead at St. Luke’s Hospital Rathgar and has been a major force in advancing radiotherapy research and innovation in Ireland for more than two decades. A former Director of Research at the St. Luke’s Radiation Oncology Network (SLRON), he has overseen some of the most impactful clinical developments in Irish radiotherapy.

Professor Armstrong trained at the Memorial Sloan Kettering Cancer Center in New York, where he directed the Lung Cancer Radiation Research Programme—bringing back with him extensive expertise in advanced radiotherapy techniques and trial methodology. Under his leadership, SLRON was one of the first Irish centres to implement Intensity Modulated Radiation Therapy (IMRT) and Stereotactic Radiosurgery (SRS), now standard in the treatment of complex cancers.