Whole body dynamic PET imaging (with MUMC+)

A project with MUMC+

In oncologic 18F-FDG positron emission tomography (PET) imaging, qualitative reporting based on visual comparison of observed FDG uptake to expected normal bio-distribution, is usually performed. However, subjective visual assessment can be challenging in case of poor tumor uptake, partial tumor response or small early stage treatment effects. Consequently, visual assessment is subject to inter-reader variability. In contrast, (semi-) quantitative analysis of FDG tumor uptake has been shown to greatly improve the accuracy and consistency of diagnostics and treatment response evaluation. 18F-FDG PET imaging facilitates accurate quantification of the metabolic rate of tumour glucose consumption, denoted by Km. However, current techniques for Km assessment require complex pharmacokinetic modelling, time-consuming dynamic (multi-time-point) PET scanning and invasive arterial blood sampling. Consequently, these techniques are not compatible with current oncologic PET examinations in which static (single-time-point) whole-body 3D-images are acquired without blood sampling. Therefore, in clinical PET imaging a surrogate for Km is used, the standardized uptake value (SUV). However, the SUV suffers from a number of important shortcoming. First, it strongly depends on the elapsed time between 18F-FDG administration and PET acquistion, necessitating a strict standardization of this uptake time. Second, the tumour uptake depends on the (total) amount of 18F-FDG available to the tumour from the arterial blood. This availability depends inter-alia on the overall 18F-FDG consumption in the body, kidney clearance and the actual whole-body distribution volume. Consequently, discrepancies between the SUV and Km have been reported which may result in a wrong diagnosis or treatment response evaluation.

AIM: The aim of this project is to develop a technique to assess Km by using whole body dynamic PET imaging.

This is achieved by developing a dynamic whole body PET acquisition protocol on a state-of-the-art digital PET/CT system available in the MUMC+. In addition, a pharmacokinetic modeling technique needs to be developed capable of processing this dynamic PET data to assess Km. Finally, the clinical added value of Km will be evaluated in a patient study.