Visualisation of Range Shortening in Carbon Ion Beams and Washout of Positron Emitter: First-in-Human Report.

BACKGROUND/AIM: Auto-activation positron emission tomography (AAPET) is one of the most promising methods to verify beam range in carbon ion radiotherapy (C-ion RT). We aimed to confirm this for the first time in a clinical setting by performing AAPET in a patient with pancreatic cancer previously receiving coil embolisation of hepatic artery pseudoaneurysm. MATERIALS AND METHODS: A 70-year-old pancreatic head cancer patient was treated with C-ion RT on a clinical dose of 4.6 Gy (RBE), followed by AAPET, to verify beam ranges in C-ion RT. RESULTS: Positron emission tomography (PET) revealed low positron emitter concentrations at the distal side of the internal metals and in the aorta compared to the dose distribution of the treatment plan, indicating range shortening by internal metals in C-ion beams and positron emitter transportation by biofluids. CONCLUSION: AAPET may detect range shortening by internal metals in the trajectory and washout of intravascular positron emitter compared to plan dose distribution.