Improving the quality of 68Ga PET images using a radionuclide-specific point spread function reconstruction (with MUMC+)

A project with MUMC+

Positron Emission Tomography (PET) explores cellular and molecular processes in vivo. With the broad availability of on-site 68Ge/68Ga-generators, 68Ga is extensively used in PET imaging of various tumors. Consequently, optimal 68Ga-PET imaging is highly important for staging and follow-up of oncological diseases. However, compared to 18F, the most commonly used PET radionuclide, 68Ga emits high-energy positrons which travel a significantly larger distance in tissue compared to 18F-generated positrons, before annihilating in two photons that are detected by the PET system. This results in a degraded spatial resolution of 68Ga-PET compared to 18F-PET images when standard, off-the-shelf reconstruction algorithms are used. This leads to a suboptimal quantification and detection of small lesions in 68Ga-PET images in the current clinical setting.

AIM: The aim of this project is to improve the image quality and clinical value of 68Ga-PET imaging by developing accurate corrections for the tissue-dependent positron range of 68Ga to improve 68Ga-PET quantification and lesion detectability.

This is achieved by incorporating 68Ga-specific corrections, based on Monte-Carlo simulations, to PET image reconstruction techniques, currently used in clinical practice. Optimization and thorough validation of this 68Ga-specific reconstruction algorithm will be performed through realistic Monte-Carlo simulations as well as real-life measurements on state-of-the-art digital PET/CT and PET/MRI systems available at the MUMC+. Finally, the image quality, quantification and lesion detectability of the developed 68Ga-specific reconstruction algorithm will be compared to commercially available reconstruction algorithms and the added diagnostic value will be evaluated in a large prospective patient study.