In-beam PET measurement of washout in rabbit using ¹¹C and ¹⁵O ion beams

In particle therapy, in-beam positron emission tomography (PET) is expected to enable in situ noninvasive confirmation of the treatment delivery. For accurate range and dose verification or three-dimensional (3D) volume imaging, however, correction of the biological washout effect in a living body is necessary. In this study, we implanted ¹¹C and ¹⁵O ion beams into rabbit brain, and observed the diffusion process to the whole body. Data were acquired by our large-bore in-beam PET 6th-prototype, which enables 3D in-beam imaging. Regions of interests (ROIs) were set as a 3D positron distribution and the time activity curves (TACs) of the brain, heart and lung region were acquired. A difference between diffusion process in ¹¹C ions and the ¹⁵O ions was observed. This study provided the new data to investigate the biological washout mechanism. (author)