A Comparison of microCT and microPET for Evaluating Lymph Node Metastasis in a Rat Model.
OBJECTIVE
The demand to optimize multidisciplinary treatment strategies in patients with benign and malignant diseases of the lung and other organs has led to the increased need of mechanistic proof-of-concept studies in preclinical small animal models using new non-invasive imaging methods. Therefore, we evaluated the role of microPET and microCT for mediastinal lymph node staging in an orthotopic lung cancer model in rats.


METHODS
Human lung cancer cells (NCI-H460) were injected transthoracically in nude rats (NIH-RNU). After 2 weeks of tumour growth, animals underwent multiphase contrast-enhanced microCT using ExiTron nano 12000 as a contrast agent and dynamic microPET using the tracer 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG). Thereafter, animals were sacrificed for histological analysis.


RESULTS
Late phase micro X-ray computed tomography (microCT) revealed the best delineation of lymph node metastases, as compared to earlier scans. In terms of an increased [(18)F]FDG uptake over time, dynamic micro positron emission tomography (microPET) delineated lymph node metastases and enabled metabolic examinations of the induced lung cancer metastases.


CONCLUSIONS
The combination of contrast-enhanced microCT and dynamic microPET is feasible in rats for the visualization of mediastinal lymph node metastases.
Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany.|Translational Lung Research Center Heidelberg, Member of the German Center for Lung Research DZL, Heidelberg, Germany.
Paul
P
Flechsig
Department of Nuclear Medicine, University Hospital Heidelberg, INF 400, 69120, Heidelberg, Germany.
Clemens
C
Kratochwil
Institute of Pathology, University Hospital Heidelberg, Heidelberg, Germany.|Translational Lung Research Center Heidelberg, Member of the German Center for Lung Research DZL, Heidelberg, Germany.
Arne
A
Warth
Department of Nuclear Medicine, University Hospital Heidelberg, INF 400, 69120, Heidelberg, Germany.
Daniel
D
Rath
Core Facility Small Animal Imaging, German Cancer Research Center, Heidelberg, Germany.
Viktoria
V
Eichwald
Molecular Radiation Oncology, German Cancer Research Center and University Hospital Center Heidelberg, Heidelberg, Germany.
Peter E
PE
Huber
Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany.|Translational Lung Research Center Heidelberg, Member of the German Center for Lung Research DZL, Heidelberg, Germany.
Hans-Ulrich
HU
Kauczor
Department of Nuclear Medicine, University Hospital Heidelberg, INF 400, 69120, Heidelberg, Germany.|Cooperation Unit Nuclear Medicine, German Cancer Research Center (DKFZ), Heidelberg, Germany.
Uwe
U
Haberkorn
Department of Nuclear Medicine, University Hospital Heidelberg, INF 400, 69120, Heidelberg, Germany. frederik@egiesel.com.|Cooperation Unit Nuclear Medicine, German Cancer Research Center (DKFZ), Heidelberg, Germany. frederik@egiesel.com.
Frederik L
FL
Giesel
D000818:Animals; D045744:Cell Line, Tumor; D003287:Contrast Media; D004195:Disease Models, Animal; D006801:Humans; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging*; D008297:Male; D049268:Positron-Emission Tomography / Q000379:methods*; D011923:Rats, Nude; D055114:X-Ray Microtomography / Q000379:methods*
D003287:Contrast Media
Computed tomography; Lung cancer; Orthotopic lung cancer model; [18F]FDG/PET-CT