Prompt-gamma imaging in particle therapy

Abstract Prompt-gamma imaging has been a source of intensive research over the years since its first proposal in 2003. Several detection approaches have been researched and developed, and many studies on prompt-gamma imaging have been conducted on its feasibility, detection systems optimisation, and possible workflows. Now, this form of particle therapy monitoring is finally arriving in clinical settings and showing impressive results. Prompt-gamma imaging may be the key to enabling crucial improvements in particle therapy, namely when considering more complex workflow scenarios, like adaptive radiotherapy using ion beams. Herein, several aspects related to prompt-gamma imaging are introduced, covering both its advantages and limitations. The need for particle therapy monitoring, the different prompt-gamma radiation detection systems, the difficulties with dealing with low emission yields and with the tools used to simulate it, the prediction tools for prompt-gamma radiation, and the translation into clinical applications are presented and discussed. Finally, some considerations are also made on the future of prompt-gamma imaging and what it may bring into particle therapy, ultimately benefiting patients worldwide.