Code Blue Response in Radionuclide Therapy Wards: A Standard Operating Procedure for Emergency Care and Radiation Safety

High-dose radionuclide therapy wards present unique challenges during medical emergencies because patients receiving therapeutic radiopharmaceuticals continue to emit ionising radiation while being managed in isolation. Standard hospital Code Blue protocols are designed for conventional clinical environments and do not address radiation exposure, radioactive contamination risks, responder protection, or coordination with radiation safety services. Conversely, existing radiation protection guidelines focus primarily on routine clinical practice and contamination control, and provide limited operational guidance for managing acute medical emergencies such as cardiac arrest. In real-world settings, healthcare providers responding to Code Blue events in radionuclide therapy wards must therefore balance the urgency of life-saving interventions with radiation safety considerations, underscoring the need for a clear, integrated, and practical standard operating procedure to guide effective and safe emergency response. This continuing medical education (CME) article provides a structured, practical Standard Operating Procedure (SOP) for managing Code Blue emergencies in high-dose radionuclide therapy wards. The SOP integrates American Heart Association life-support principles with internationally accepted radiation safety guidance from the International Atomic Energy Agency, International Commission on Radiological Protection, World Health Organisation, and national regulatory authorities. Key components include early recognition and activation of Code Blue, clearly defined multidisciplinary roles, exposure control strategies based on time, distance, and shielding, contamination prevention measures, thyroid blockade protocols for radioiodine exposure, and safe post-event decontamination practices. Special emphasis is placed on the role of the Radiological Safety Officer in real-time supervision, dose monitoring, contamination control, and documentation during emergency response. The article also outlines recommended dose constraints for responders, ethical considerations during life-saving interventions, and the importance of regular training and simulation drills. This SOP is intended as an educational framework to support preparedness, improve responder confidence, and enhance safety during emergencies in radionuclide therapy settings. The principles described are adaptable to a wide range of nuclear medicine facilities and are designed to complement existing institutional Code Blue policies while maintaining compliance with radiation protection standards.