Professor Joerg Lehmann is an accredited Radiation Oncology Medical Physicist at Calvary Mater Newcastle, where he serves as Lead Medical Physicist for Research. His research focuses on dosimetry, quality assurance, image guidance for radiotherapy, and data mining.
Joerg leads a groundbreaking project to develop the first system for continuously and directly measuring internal anatomy to guide breast cancer radiation treatment during deep inspiration breath hold, currently in clinical trials.

He also heads a project to enhance the sensitivity of clinical quality assurance systems to improve radiation oncology treatments. This project involves an international team from Australia, the UK, and the US, closely collaborating with the National Physical Laboratory in the UK.

He is involved in several international working groups, including a joint task group of the American Association of Medical Physics (AAPM) and the European Society for Radiotherapy and Oncology (ESTRO) on performance validation of surrogate assessment systems (TG 360). Joerg is a member of the AAPM Global Research and Scientific Innovation Committee and serves as Vice Chair of the Global Clinical Trials Subcommittee.

As a physicist for the Transtasman Radiation Oncology Group (TROG), Joerg contributes to radiotherapy dosimetry audits and quality assurance. He previously chaired the Global Quality Assurance of Radiation Therapy Clinical Trials Harmonisation Group (GHG), which standardises and improves quality assurance across multi-institutional clinical trials.

In Australia, Joerg is a recognized expert in clinical dosimetry, serving on the Radiation Dosimetry Advisory Group of ARPANSA and the Australasian College of Physical Sciences and Engineering in Medicine (ACPSEM).

As an acknowledged expert in clinical dosimetry in Australia, Joerg serves on the Radiation Dosimetry Advisory Group of the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) and the Australasian College of Physical Sciences and Engineering in Medicine (ACPSEM).