Dr Siobhra O'Sullivan

Consultant Radiation Oncologist
Dr Siobhra O'Sullivan Consultant Radiation Oncologist

Areas of Specialty

  • Radiation Oncology
  • Breast Cancer
  • Neuro-Spine Metastases
  • Oligometastases
  • Advanced Radiotherapy Techniques
  • Stereotactic Radiosurgery (SRS)
  • Stereotactic Ablative Radiotherapy (SABR)
  • Radiotherapy


Dr O’Sullivan graduated from Trinity College Dublin and is a Foundation Scholarship Fellow of the University. She completed her general medical training at St James’s Hospital and Tallaght University Hospital, and has also worked at the Royal Free Hospital in London. Dr O’Sullivan completed specialist training in radiation oncology through the RSCI at St Luke’s Radiation Oncology Network and Galway University Hospital.


Dr O’Sullivan’s fellowship training has focused on the use of stereotactic radiotherapy for both intracranial and extracranial disease. In March 2018 she attended the Harvard-affiliated Dana-Farber/Brigham and Women’s Cancer Centre in Boston to gain experience in stereotactic radiotherapy of liver and pancreatic cancers – this fellowship was kindly funded by the Donal Hollywood Travelling Fellowship award. Dr O’Sullivan completed further fellowship training through St Luke’s Institute of Cancer Research where she successfully developed and implemented the Spine Stereotactic Radiotherapy program at St Luke’s Radiation Oncology Network/Beaumont Hospital, along with development of a clinical trial for patients with spine metastases. She has authored multiple research papers and is an active member of Cancer Trials Ireland.

More recently Dr O’Sullivan has worked as a locum consultant at St Luke’s Radiation Oncology Network, and now joins the Beacon Hospital on a full time basis.

Her areas of interest include radiotherapy management of breast cancer, brain and spine metastases, and the use of advanced radiotherapy techniques including stereotactic radiotherapy for oligometastatic disease.