PET/CT-Assessment of Liver Tumor Ablation

Overview

In this research study, the investigators are evaluating whether ammonia PET scans or FDG PET perfusion scans are more useful in helping radiologists determine whether liver tumors were successfully destroyed by the heating or freezing procedures (ablations) than other scans currently available to radiologists, such as CT scans and MRI scans. The currently available scan (usually a CT scan with contrast dye) is not always effective in showing how completely the tumor has been destroyed. The ammonia PET scan is a different way of looking at how much tumor has been destroyed. This study will compare the standard scan (CT scan) with the ammonia PET scan.

The plan for this study involves the non-therapeutic administration of a radiopharmaceutical, N-13 ammonia or F-18 fluorodeoxyglucose, one to two doses, during the tumor ablation procedure. The perfusion PET scan is a diagnostic imaging test. The tumor ablation procedure is performed according to our standard clinical practice and is not itself a research activity. The use of N-13 ammonia or F-18 fluorodeoxyglucose to image liver perfusion with a PET scanner is the research portion of the procedure. The patient will receive one or two doses of N-13 ammonia (10 mCi (millicurie)/dose) for intraprocedural assessment of ablation results. Not more than two doses will be administered and one or both doses will be administered on the day of the tumor ablation procedure only. The ammonia perfusion scan will not be used to change or modify the ablation procedure. After the screening procedures confirm that that the participant is eligible to participate in the research study: * Ammonia Perfusion PET: The participant will be scheduled for the tumor ablation procedure as part of the participant's routine care. If the participant decided to take part in this research study, then the participant will have one or two ammonia perfusion PET scans during the ablation procedure to see if the ablation was successful or not as compared to standard CT scanning. The ammonia perfusion PET scans are the research part of the participant's procedure. The rest of the participant's procedure is not research. The participant will receive one or two doses of the radioactive tracer called N-13 ammonia. This tracer is administered through the same IV (thin tube placed in a vein) used by the Anesthesiologist to give the participant routine medications that relax the participant, prevent pain, and allow the participant to sleep during the procedure. This tracer does not treat the participant's tumor in any way. Instead, the tracer may allow the radiologist to better see how much of the participant's tumor was destroyed. * Photographs: Photographs may be taken during the procedure. Care will be taken to ensure these do not reveal the participant's identity. * Clinic visits: The investigators routinely see patients after tumor ablation procedures within one to two weeks after the procedure and then every three months after the procedure for one to two years, and as needed in the future. Accordingly, the clinic visits are routine and not an added research commitment.