5th EuropEan MolEcular IMagIng MEEtIng - ESMI

42 Introduction:
WarSaW, poland May 26 – 29, 2010
Cerenkov radiation imaging of a xenograft murine model of mammary carcinoma
Boschi F. (1) , Calderan L. (1) , D’ambrosio D. (2) , Marengo M. (2) , Fenzi A. (1) , Calandrino R. (3) , Sbarbati A. (1) , Spinelli A. E. (3) .
(1) University of Verona,
(2) S. Orsola – Malpighi University Hospital,
(3) S. Raffaele Scientific Institute.
federico@anatomy.univr.it
2-[18F]fluoro-2-deoxy-D-glucose
( 18 F-FDG) is a well known radiotracer for the in
vivo studies of several diseases. In a previous paper
[1] we showed that the positrons emitted by 18 F-FDG,
travelling into tissues faster than the speed of light
in the same medium, are responsible of Cerenkov
Radiation (CR) emission which is prevalently in the
visible range. The purpose of this work was to show
that Cerenkov radiation escaping from tumour tissues
of small living animals injected with 18 F-FDG
can be detected with optical imaging (OI) techniques
using a commercial optical instrument equipped
with charged coupled detectors.
Methods: In order to demonstrate as a proof of
principle the possibility of imaging tumours using
CR we studied an experimental model of mammary
carcinoma named BB1. BB1 tumours were obtained
by subcutaneous injection of BB1 cells, which are
epithelial cells, from spontaneous mammary carcinomas
of FVB transgenic mice for HER-2/neuT
oncogene. The BB1 carcinomas exhibit histopatological
and vascular features very similar to those
of the parent spontaneous tumours. The BB1 mouse
tumour model was well explained by Galiè and coworkers
[2] and will not be described here.
The images show a comparison between images acquired pre injection (left image) and 1 hour after 18F-
FDG injection for two mice. White arrows indicate the position of the tumour masses.
imaging life
Mice injected with 18 F-FDG or saline solution underwent
dynamic OI acquisition and a comparison
between images were performed. Multispectral analysis
of the radiation was used to estimate the deepness
of the source of Cerenkov light. Small animal
PET images were also acquired in order to compare
the 18 F-FDG bio-distribution measured using OI
and PET scanner.
Results: The first Cerenkov in vivo whole body images
of tumour bearing mouse and the measurements
of the emission spectrum (560-660 nm range) were
presented. Brain, kidneys and tumour were identified
as a source of visible light in the animal body:
the tissue time activity curves reflected the physiological
accumulation of 18 F-FDG in these organs.
The identification is confirmed by the comparison
between CR and 18 F-FDG images.
Conclusions: These results will allow the use of
conventional optical imaging devices for the in
vivo study of the cancer glucose metabolism and
the assessment, for example, of anti-cancer drugs.
Moreover this demonstrates that 18 F-FDG can be
employed as it is as bimodal tracer for PET and OI
techniques.
References:
1. Spinelli A E et al; Phys.
Med. Biol. 55(2):483-
495 (2010)
2. Galiè M et al;
C a r c i n o g e n e s i s .
26:1868-1878 (2005)