PET Assessment of Acute Lung Transplant Rejection

Positron emission tomography with fluorodeoxyglucose (FDG-PET) is a potential way we can measure lung inflammation. FDG-PET imaging is a clinically accepted and FDA-approved method that is commonly used in the diagnosis and management of cancer. PET is a machine that detects radiation and generates pictures using a donut shaped scanner similar in appearance to an x-ray "CAT" computerized axial tomography or computed tomography (CT) scan. FDG stands for \[18F\] (flourine 18) fluorodeoxyglucose, a radiolabeled sugar that is used to identify areas of inflammation with the PET scanner. A CT scan takes a picture of what the lungs and airways look like. T cells are the primary cause of acute rejection of lung transplants. Because T cells must divide in order to be activated and cause rejection, imaging them while they are dividing is another way that we can determine whether acute rejection is occurring. A new PET tracer called \[18F\]ISO-1 (18F-labeled σ2-receptor ligand for PET, N-(4-(6,7-dimethoxy-3,-4-dihydroisoquinolin-2(1H)-yl)butyl)-2-(2-18F-fluoroethoxy)-5-methylbenzamide (18F-3c), binds to dividing cells. Therefore, \[18F\]ISO-1 may help us measure acute rejection more accurately. \[18F\]ISO-1 is an investigational drug.