Battle of the Titans TG-51 vs. TRS-398: A Global Dosimetry Debate
Description
Reference dosimetry forms the foundation of accurate dose delivery in radiation therapy. Two primary calibration protocols dominate clinical practice: AAPM’s TG-51, used throughout North America and select countries, and IAEA’s TRS-398, adopted widely across most other regions. While both aim to establish the same absorbed dose to water, their measurement steps, and some underlying assumptions differ. This session will bring these differences to life through a lively point–counterpoint debate between two experienced clinical physicists who routinely implement each protocol. Across three concise rounds, the speakers will first introduce the physics principles of their respective protocols for both photon and electron beams and highlight the ease of measurement. In the second round, each will identify potential failure modes in the opposing protocol, emphasizing how these weaknesses could translate into clinical safety issues. In the final round, each physicist will conclude by defending their chosen standard. A third speaker – an experienced international trainer - will provide guidance for educators and trainers transitioning between regions where different standards prevail. The session will conclude with a moderated audience discussion on the global future of reference dosimetry: should efforts continue to maintain both protocols, or is it time to harmonize toward a single international standard?