Journal of nuclear medicine : official publication, Society of Nuclear Medicine
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In high-activity radioiodine therapies for differentiated thyroid cancer, blood dosimetry has been developed to estimate the maximum tolerable activity (MTA) of (131)I that can be safely administered without leading to toxic effects. The reference protocol involves a series of both blood sampling (BS) and whole-body counting (WC) over a period of several days. The aim of this retrospective study was to identify simplified protocols without an appreciable loss of accuracy. ⋯ The pretherapy blood dosimetry protocol can be substantially shortened and may be beneficial to patients and patient management while reducing the radiation exposure to medical staff.
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The joint maximum-likelihood reconstruction of activity and attenuation (MLAA) for emission-based attenuation correction has regained attention since the advent of time-of-flight PET/MR imaging. Recently, we improved the performance of the MLAA algorithm using an MR imaging-constrained gaussian mixture model (GMM). In this study, we compare the performance of our proposed algorithm with standard 4-class MR-based attenuation correction (MRAC) implemented on commercial systems. ⋯ The proposed MLAA algorithm is promising for accurate derivation of attenuation maps on time-of-flight PET/MR systems.
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Prostate-specific membrane antigen (PSMA) is a promising target for diagnosis and treatment of prostate cancer. EuK-Subkff-(68)Ga-DOTAGA ((68)Ga-PSMA Imaging & Therapy [PSMA I&T]) is a recently introduced PET tracer for imaging PSMA expression in vivo. Whole-body distribution and radiation dosimetry of this new probe were evaluated. ⋯ (68)Ga-PSMA I&T exhibits a favorable dosimetry, delivering organ doses that are comparable to (kidneys) or lower than those delivered by (18)F-FDG.