A Clinically Suitable Approach to Whole-Body Imaging for Quantification of Regional Perfusion: Validation of Positron Emission Tomography (PET) with 62Cu-ETS and Image-based Tracer Kinetic Modeling
Background & Hypothesis: We hypothesize that whole-body PET imaging with 62Cu-ETS and readily implemented tracer kinetic models, can enable absolute quantification of regional perfusion (mL•min-1•g-1) in a fashion that is reproducible; readily standardized across institutions; and logistically suitable for clinical implementation.
Experimental Design: Thirty-five paired 62Cu-ETS and H215O studies were performed in six Göttingen minipigs to validate the use of image-derived input functions. H215O estimates of tissue perfusion served as a reference standard for comparison with 62Cu-ETS. To demonstrate quantitative whole-body perfusion imaging in humans, paired 62Cu-ETS and H215O studies were performed in 14 renal cell carcinoma patients both prior to and following sunitinib therapy.
Results: The pig studies showed a strong correlation between regional blood flow estimates made with 62Cu-ETS and H215O, using image-derived input functions with tracer kinetic model-based corrections for 62Cu-ETS decomposition in blood (slope=0.932, R2=0.746). High quality voxel-wise 62Cu-ETS perfusion and blood volume parametric images demonstrated a strong correlation with H215O across all tissues within the imaging field-of-view. Using a same-day test-retest design, which was then repeated across two weeks, the animal study demonstrated good test-retest variability (TRV) for 62Cu-ETS and H215O with TRV of 6.3% ± 5.40% and 5.0% ± 4.77%, respectively. These findings strongly support application of the modeling methods to the human data, which is currently in progress.
Conclusion & Potential Impact: Whole-body imaging to non-invasively quantify regional perfusion holds promising potential for clinical implementation, using 62Cu-ETS PET coupled with tracer kinetic models that rely solely on the acquired imaging data.
Copyright (c) 2018 Monica Cheng, Nathaniel J. Smith, Wendy L. Territo, Carla J. Mathias, James W. Fletcher, Theodore F. Logan, Mark A. Green, Gary D. Hutchins
This work is licensed under a Creative Commons Attribution 4.0 International License.