18F-FDG Tumor and Infectious Imaging Radiotracer

                       Radiation Doses                                     (BGL = Blood Glucose Level)

            Fluordeoxiglucose labelled with 18F, is the most valuable PET tracer employed to detect several pathologic conditions, mainly malignancies and more recently inflammatory and infectious conditions. 18F has a half life of 109 min. It is estimated that this compound can be shipped to places about a radius of 4 hours from the cyclotron and still be adequate for clinical studies.

            FDG is a glucose analogue molecule and differs chemically from it because it takes into position 2 a 18F atom instead of an OH group. FDG is taken up by the cell transporters and phosphorelized, but not metabolized. In this way its concentration inside the cell is very significant. Malignant cells of a variety of tumors use glucose intensively and so can be detected by labeled 18F-FDG. Likewise, cells involved in inflammatory and infective disease disease such as neutrophils, macrophages, mastocits, also concentrate FDG. Other tracers less commonly used  to diagnose tumors less avid of glucose are 11C labeling the amino acids metionine and coline. These are introduced into cell proteins and so become part of the cell proper.

References:

1  Rohren EM, Turkington TG, Coleman RE. Clinical applications of PET in oncology. Radiology. 2004 May;231(2):305-32.

2  Basu S, Ranade R.18-Fluoro-deoxyglucose-PET/Computed Tomography in Infection and Aseptic Inflammatory Disorders: Value to Patient Management. PET Clin. 2015 Jul;10(3):431-9. doi: 10.1016/j.cpet.2015.03.006. Epub 2015 Apr 8.

3  Hess S, Hansson SH, Pedersen KT, Basu S, Høilund-Carlsen PF.FDG-PET/CT in Infectious and Inflammatory Diseases. PET Clin. 2014 Oct;9(4):497-519, vi-vii. doi: 10.1016/j.cpet.2014.07.002. Epub
2014 Aug 10.

4  Vaidyanathan S, Patel CN, Scarsbrook AF, Chowdhury FU.FDG PET/CT in infection and inflammation--current and emerging clinical applications. Clin Radiol. 2015 Jul;70(7):787-800. doi: 10.1016/j.crad.2015.03.010. Epub 2015 Apr 25.