Intraoperative imaging of tumors using Cerenkov luminescence endoscopy: a feasibility experimental study.
Cerenkov luminescence imaging (CLI) is an emerging new molecular imaging modality that is relatively inexpensive, easy to use, and has high throughput. CLI can image clinically available PET and SPECT probes using optical instrumentation. Cerenkov luminescence endoscopy (CLE) is one of the most intriguing applications that promise potential clinical translation. We developed a prototype customized fiberscopic Cerenkov imaging system to investigate the potential in guiding minimally invasive surgical resection.


METHODS
All experiments were performed in a dark chamber. Cerenkov luminescence from (18)F-FDG samples containing decaying radioactivity was transmitted through an optical fiber bundle and imaged by an intensified charge-coupled device camera. Phantoms filled with (18)F-FDG were used to assess the imaging spatial resolution. Finally, mice bearing subcutaneous C6 glioma cells were injected intravenously with (18)F-FDG to determine the feasibility of in vivo imaging. The tumor tissues were exposed, and CLI was performed on the mouse before and after surgical removal of the tumor using the fiber-based imaging system and compared with a commercial optical imaging system.


RESULTS
The sensitivity of this particular setup was approximately 45 kBq (1.21 μCi)/300 μL. The 3 smallest sets of cylindric holes in a commercial SPECT phantom were identifiable via this system, demonstrating that the system has a resolution better than 1.2 mm. Finally, the in vivo tumor imaging study demonstrated the feasibility of using CLI to guide the resection of tumor tissues.


CONCLUSIONS
This proof-of-concept study explored the feasibility of using fiber-based CLE for the detection of tumor tissue in vivo for guided surgery. With further improvements of the imaging sensitivity and spatial resolution of the current system, CLE may have a significant application in the clinical setting in the near future.
Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bio-X Program, Canary Center at Stanford for Cancer Early Detection, Stanford University, Stanford, California 94305, USA.
Hongguang
H
Liu
Colin M
CM
Carpenter
Han
H
Jiang
Guillem
G
Pratx
Conroy
C
Sun
Michael P
MP
Buchin
Sanjiv S
SS
Gambhir
Lei
L
Xing
Zhen
Z
Cheng
D000818:Animals; D004724:Endoscopy / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D019788:Fluorodeoxyglucose F18; D005910:Glioma / Q000000981:diagnostic imaging / Q000601:surgery; D007432:Intraoperative Period; D008163:Luminescent Measurements; D051379:Mice; D057054:Molecular Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D049268:Positron-Emission Tomography
D019788:Fluorodeoxyglucose F18