The aim of the EndoTOFPET-US collaboration is the development of an endoscopic TOF-PET system with integrated ultrasound probe. This project became only recently possible due to the evolving miniaturisation of components. Usually, the detectors in positron emission tomography are placed on a ring surrounding the patient. Using SiPMs it is possible to integrate part of the system into a endoscopic probe. Due to the close proximity of this device to the tissue under investigation, it covers a large spatial angle despite its small size. At the same time, the endoscopic probe can be used for ultrasound measurements. Combining both imaging measurements leads to new diagnostic possibilities. A high photon detection efficiency and a efficient coincidence discrimination enforced by a precise time resolution leads to an improved sensitivity. This can be used to reduce the strain for the patient both by lowering the radioactive dose and the examination time. A potential application for this detector are diseases like prostatic or pancreatic cancer.
This novel approach is challenging in many fields. The detector R&D group at KIP is involved in to central fields, data aquisition and detector integration. For data aquisition, fast and reliable electronics is needed to steer and read out the sensors of the inner and outer detector part. The goal is achieve a time resolution of better than 200ps, raising the sensitivity by improving the coincidence discrimination. For this purpose an ASIC chip named STiC is developed which is able to handle 64 channels of the outer plate. At the same time, fast scintillating crystals are required for this purpose and are under investigation.
One major challenge for the detector integration is the development of a detector head comprising all the necessary components like crystals and photo detectors in a compact housing, which is compatible to commercially available endoscopic probes.