Published online by Cambridge University Press: 06 July 2010
Introduction
At present there is no clinical role for whole or half body imaging with 18F-fluoro-2-deoxy-D-glucose (FDG)–positron emission tomography (PET) in detecting breast cancer, but this technique has been shown to be useful in staging and restaging breast cancer, in the evaluation of response to therapy, and in problem solving when conventional imaging results are equivocal. In these scenarios FDG–PET often demonstrates loco-regional or unsuspected distant disease that affects clinical management.
Positron emission tomography
PET is an imaging technique increasingly used in oncology. It may map functional activity before structural changes have taken place. The most commonly used isotope is FDG, a glucose analogue which, like normal glucose, is taken up by cells via the membrane glucose transporter system and phosphorylated by hexokinase. Unlike glucose, the metabolic product FDG-6-phosphate does not cross the cell membrane and is trapped in cells. FDG accumulation is dependent on the rate of transport through the cell membrane mediated by glucose transporters (GLUT). Many malignancies, including breast cancers, show increased expression of GLUT-1, contributing to increased FDG accumulation. FDG may also accumulate in non-malignant areas of infection or inflammation leading to false-positive findings.
Technique
An intravenous injection of 300 to 400 megabecquerels (MBq) of FDG is used in most institutions and the patient imaged at least one hour after injection. Delaying the time of imaging may improve the tumor-to-background ratio.
To save this book to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.