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Date of Award
Doctor of Philosophy (PhD)
Radioembolization of yttrium-90 (Y-90) microspheres is used to treat primary and secondary cancers in the liver. Though this therapy has existed for decades, the treatment is not well optimized from treatment planning to post-procedural assessment. Recently, there has been a surge to utilize the small positron yield from the radioactive decay of Y-90 for post-radioembolization positron emission tomography (PET) imaging of the microsphere activity distribution. These images provide promise for dosimetry assessment, identifying extrahepatic uptake and possible under-dosed lesions that may benefit from subsequent therapy. However, due to the low positron statistics and high flux of Bremsstrahlung radiation, PET imaging of Y-90 presents with its own unique set of challenges. In this work, we optimized the PET imaging acquisition and reconstruction parameters when imaging with a hybrid PET/MRI scanner to offer the most accurate images for quantitative dosimetric applications. We then tested the variability of imaging Y-90 with PET across multiple institutions in a world-wide phantom study in preparation for a multi-institutional phase I/II clinical trial. Lastly, we determined the clinical utility of using Y-90 PET-based dosimetry to predict clinical outcomes and assess how well it correlates with pre-treatment imaging.
Parag J. Parikh
Mark A. Anastasio, Hong Chen, Harold H. Li, Richard L. Wahl,