Optimizing dosimetric accuracy in radioembolization: comparative effectiveness of SPECT/CT, planar imaging, and PET/CT for lung shunt fraction assessment.

Background: In radioembolization therapy for hepatic malignancies, the accurate estimation of lung shunt fraction (LSF) is crucial to minimize the risk of radiation-induced pneumonitis and fibrosis due to hepatopulmonary shunting of yttrium-90 (90Y)-microspheres. This study aimed to compare the accuracy and precision of LSF estimation using technetium-99m macroaggregated albumin single photon emission computed tomography ([99mTc]Tc-MAA SPECT) LSF, [99mTc]Tc-MAA planar LSF, and 90Y PET LSF in patients undergoing 90Y-radioembolization.

Material And Methods: A retrospective study was conducted involving 15 patients diagnosed with hepatocellular carcinoma (HCC) or liver metastases and planned to undergo transarterial radioembolization with 90Y SirSpheres after multidisplinary team discussion.

The role of activity, scan duration and patient's body mass index in the optimization of FDG imaging protocols on a TOF-PET/CT scanner.

Background: Time-of-flight (TOF) PET technology determines a reduction in the noise and improves the reconstructed image quality in low count acquisitions, such as in overweight patients, allowing a reduction of administered activity and/or imaging time. However, international guidelines and recommendations on the F-fluoro-2-deoxyglucose (FDG) activity administration scheme are old or only partially account for TOF technology and advanced reconstruction modalities. The aim of this study was to optimize FDG whole-body studies on a TOF-PET/CT scanner by using a multivariate approach to quantify how physical figures of merit related to image quality change with acquisition/reconstruction/patient-dependent parameters in a phantom experiment.