A dual radiologic contrast agent protocol for 18F-FDG and 18F-FLT PET/CT imaging of mice bearing abdominal tumors.
OBJECTIVE
The aim of the study was to improve abdominal tumor detection by use of a dual radiologic contrast protocol.


METHODS
eXia160® (Benitio international) was mixed with 2-deoxy-2-[¹⁸F]fluoro-D: -glucose or 3'-[¹⁸F]fluoro-3'-deoxythymidine for intravenous (IV) injections. Omnipaque® 300 (GE healthcare) was used for intraperitoneal (IP) injections. Positron emission tomography/computed tomography (PET/CT) scans were acquired on a Siemens Biograph® equipped with point spread function reconstruction. The optimal concentration and injection schedule of IP contrast agent was studied in 12 mice. The impact of IP contrast media on PET quantitative accuracy was investigated by phantom studies and by imaging six mice before and after IP injection of Omnipaque®. The impact of a dual contrast media protocol on tumor delineation and quantitation was evaluated in 15 tumor-bearing mice using ex vivo counting as the reference.


RESULTS
The optimal sequence was a mixture of tracer plus IV contrast agent followed by 1 mL of IP contrast agent (20 mg iodine/mL) administered 10 min before PET/CT acquisition. Phantom studies showed that the use of a 20-mg iodine/mL concentration of Omnipaque® led to a 4.8% overestimation of radioactivity concentration, as compared to saline. This was confirmed by animal studies that demonstrated a 4.3% overestimation. Tumor detection was excellent and correlation between PET/CT quantitative data and ex vivo counting was good (r² = 0.91, slope = 0.7).


CONCLUSIONS
A dual radiologic contrast protocol is useful in PET/CT scanning of mice bearing abdominal tumors. Contrast agents used in this manner lead to a small but acceptable overestimation of quantitative PET data.
Aide
Nicolas
N
Bioticla Team, EA 1772, IFR 146 ICORE, GRECAN, François Baclesse Cancer Centre and Caen University, Caen, France. n.aide@baclesse.fr.|PET Centre, Caen University Hospital and François Baclesse Cancer Centre, Caen, France. n.aide@baclesse.fr.|Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia. n.aide@baclesse.fr.|Nuclear Medicine Department, Centre François Baclesse, Avenue Général Harris, 14076, Caen cedex 5, France. n.aide@baclesse.fr.
Kinross
Kathryn
K
Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia.|Sir Donald and Lady Trescowthick Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Australia.
Beauregard
Jean-Mathieu
JM
Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia.
Neels
Oliver
O
Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia.
Potdevin
Titaina
T
Sir Donald and Lady Trescowthick Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Australia.
Roselt
Peter
P
Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia.
Dorow
Donna
D
Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia.|Sir Donald and Lady Trescowthick Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Australia.
Cullinane
Carleen
C
Sir Donald and Lady Trescowthick Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Australia.
Hicks
Rodney J
RJ
Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, Australia.|Sir Donald and Lady Trescowthick Laboratories, Peter MacCallum Cancer Centre, East Melbourne, Australia.|The Department of Medicine, The University of Melbourne, Parkville, Australia.
D000008:Abdominal Neoplasms / Q000000981:diagnostic imaging*; D000818:Animals; D001201:Ascites / Q000473:pathology; D003287:Contrast Media / Q000008:administration & dosage; D015224:Dideoxynucleosides / Q000008:administration & dosage; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage; D007275:Injections, Intravenous; D051379:Mice; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed
D003287:Contrast Media; D015224:Dideoxynucleosides; D019788:Fluorodeoxyglucose F18; C002854:alovudine