Rahul Anil Sheth MD, Presenter: Nothing to Disclose

Lee Josephson PhD, Abstract Co-Author: Nothing to Disclose

Umar Mahmood MD, PhD, Abstract Co-Author: Research agreement, Aposense

A fluorescent analog to FDG-PET would greatly expand the clinical utility of metabolic imaging by allowing for the introduction of this imaging paradigm into intraoperative and minimally invasive settings. We present an evaluation of 2-NBDG, a fluorescently-labeled glucose molecule, as a molecular beacon of glucose utilization through both in vitro and in vivo experimentation; we then present several clinically relevant applications for this imaging modality.

2-NBDG uptake into cultured tumor cells was investigated using fluorescence microscopy. The competitive inhibition of 2-NBDG uptake by excess free glucose in the growth medium was compared against 18F-FDG uptake inhibition. Extension into the macroscopic regime was explored by measuring 2-NBDG uptake in the brain of a mouse experiencing a generalized seizure, and in subcutaneously implanted tumors in mice during fed and fasting states. The spatial resolution and accurate localization of 2-NBDG into malignant tissues was interrogated by imaging uptake in an RFP-labeled tumor grown in a dorsal window chamber implanted in a mouse. The clinical relevance of 2-NBDG imaging was examined by performing fluorescence colonoscopy in an orthotopic murine model of colorectal cancer, and by correlating pre-operative FDG-PET imaging of peritoneal tumors with intraoperative fluorescence imaging.

2-NBDG was avidly transported into tumor cells in culture and exhibited a similar uptake inhibition to 18F-FDG by excess glucose in the growth media. Uptake was significantly increased in the brain of an animal experiencing seizures versus control, and in subcutaneous tumors after the animals were kept NPO for 24 hours vs ad libidum feeding. The clinical utility of 2-NBDG was confirmed by the ready detection of colon adenomas with fluorescence colonoscopic imaging. Peritoneal tumors found to be FDG-PET avid were readily visualized by intraoperative imaging with 2-NBDG as well.

FDG-PET imaging plays a very important role in the diagnosis and management of a wide number of diseases. We present herein an optical analog of FDG-PET, to serve as a supplement that extends the applicability of metabolic imaging to minimally invasive and intraoperative settings.

This technology allows for the translation of metabolic activity data from non-invasive FDG-PET imaging into intraoperative and minimally invasive settings.

Sheth, R, Josephson, L, Mahmood, U, Evaluation and Clinically Relevant Applications of a Fluorescent Imaging Analog to FDG-PET.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8005128.html