OpenPET: a novel open-type PET system for 3D dose verification in particle therapy

The OpenPET is the world's first open-type 3D PET scanner for PET image-guided particle therapy such as in situ dose verification and direct tumour tracking. Even with a full-ring geometry, the OpenPET has an open gap between its two detector rings through which the treatment beam passes. Following the initial proposal of the dual-ring OpenPET (DROP), the single-ring OpenPET (SROP) was also proposed as a more efficient geometry than DROP in terms of manufacturing cost and sensitivity. A small SROP prototype was developed and feasibility of visualizing a 3D distribution of beam stopping positions inside a phantom was shown with the help of radioisotope particle beams, used as primary beams. Following these results, a full-size whole-body SROP prototype was developed. (paper)