Value of [68Ga]Ga-PSMA-11 PET/MRI in the Assessment of Liver Cirrhosis

DRUG

Injection of a gadolinium contrast agen

All patients will be requested to have an injection of a gadolinium contrast agent, which may be either Gadavist (Bayer, Whippany, NJ, USA), Eovist (Bayer, Whippany, NJ, USA), or Dotarem (Guerbet, Princeton, NJ, USA) (ancillary drugs). * About halfway through the examination, the same intravenous catheter used to inject the radiotracer will be used to inject the MRI contrast agent; * After being positioned on the PET/MRI table, the nuclear medicine technicians will connect the patient to the MRI-safe power-injector; - The catheter will be flushed before and after injection with 0.9% saline solution;

DRUG

Radiotracer Injection

All patients will be requested to have a radiotracer injection of Ga-PSMA (Illucix, Telix Pharmaceuticals). An intravenous catheter will be placed in an arm or hand vein for injection of the Ga-PSMA; * The catheter will be flushed post-injection with 0.9% saline solution * The injected dose and the time of injection will be recorded. * The subjects will be positioned on the scanner table; support devices under the back and/or legs will be used to enable the patient to comfortably maintain his/her position throughout the scan

DIAGNOSTIC_TEST

Imaging

PET, MRI and fused PET/MRI images will be qualitatively assessed in comparison to standard of reference data. For PET, standard of reference will be PET images as obtained by standard PET acquisition mode. Attenuation correction of the PET images will be performed using a 2-point Dixon MRI sequence and a vendor-specific atlas-based attenuation map. 3D scatter correction by single scatter simulation is also performed using the MRI-derived attenuation data. MRI images will be compared to dedicated 3 Tesla MR upper abdominal protocol images acquired at the MGH in patients with liver cirrhosis, including those undergoing imaging follow-up after systemic or local regional therapies. For PET/MRI fused images, the standard of reference will be co-registered and fused PET/MRI images as obtained by standard MRI sequences/reconstructions.

Assessment of LI-RADS with Ga-PSMA-PET/MRI

Time frame: 1-2 Months

PET, MRI, and fused PET/MRI images will be evaluated to determine the effect of contrast-enhanced Ga-PSMA/PETMRI on evaluating liver nodules. Images will be evaluated at least 4 weeks apart from each other to reduce recall bias. Each lesion described by the readers of the imaging modalities will then be classified accordingly into true positive, false positive, true negative, or false negative. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value will then be computed using adequate proportions as estimates.

What is a clinical trial?

A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.

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Will I receive a placebo instead of treatment?

When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.

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