Validation of a new method for quantifying in vivo murine tumor necrosis by sonography.
OBJECTIVE
At present, the gold standard to evaluate tumor necrosis is histology. We described here a new method to quantify the degree of tumor necrosis by ultrasonography. This technique combines ultrasound exploration of tissue and post-treatment of the numerical sequences using a dedicated software to evaluate backscattered power within the tumor.


METHODS
In order to establish that the backscattered power could be considered as a relevant marker of tumor necrosis, we performed (1) intra- and interoperator reproducibility in estimation of tumor dimensions obtained on sonographic scans; and (2) intra- and interoperator reproducibility in quantification of backscattered power in postprocessing using the HDILab software. The third part of the study consisted of correlating the degree of tumor necrosis estimated by histology and the ultrasound backscattered power, both obtained on xenografted melanomas at different days after tumor transplantation.


RESULTS
Results concerning tumor size estimations and quantification of echogenicity were reproducible (coefficient of variation < 4.33%). The degree of necrosis measured in histology and echogenicity were significantly negatively correlated (P < 0.003).


CONCLUSIONS
In conclusion, backscattered power could be considered as a relevant parameter to quantify tumor necrosis in vivo.
Rouffiac
Valérie
V
Laboratoire d'Imagerie du Petit Animal, UMR CNRS 8121, Institut Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif Cedex, France. rouffiac@igr.fr
Bouquet
Céline
C
Lassau
Nathalie
N
Opolon
Paule
P
Koscielny
Serge
S
Peronneau
Pierre
P
Perricaudet
Michel
M
Roche
Alain
A
D000818:Animals; D008546:Melanoma, Experimental / Q000000981:diagnostic imaging / Q000473:pathology; D051379:Mice; D008819:Mice, Nude; D009336:Necrosis; D009374:Neoplasms, Experimental / Q000000981:diagnostic imaging* / Q000473:pathology*; D009447:Neuroblastoma / Q000000981:diagnostic imaging / Q000473:pathology; D015203:Reproducibility of Results; D012984:Software; D014463:Ultrasonography