Caracterización ecográfica de un modelo experimental de metástasis hepáticas de carcinoma de colon / Ultrasonographic characterization of an experimental model of liver metastases from colon carcinoma in rats

Objetivo: Determinar las características ultrasonográficas de la patología metastásica hepática inducida en un modelo múrido, para evaluar la utilidad de la ecografía en la valoración no invasiva de la infiltración tumoral. Material y métodos: El hígado de 46 ratas WAG/RijCrl fue diseminado con células singénicas de carcinoma colorrectal CC-531 mediante inoculación intraesplénica. En los días 21, 28, 35, 42 y 70 posteriores a la siembra tumoral, se realizaron series de ecografías para valorar inducción tumoral en diferentes grupos de animales; 37 ratas se estudiaron mediante sonda lineal de 10Mhz y 9 con sonda multifrecuencia de 6–18Mhz. Como signos ecográficos de desarrollo tumoral se consideró la detección de nódulos intrahepáticos, festoneado del contorno hepático, megalias de lóbulos y masas extrahepáticas. Los hallazgos ecográficos se verificaron tras necropsia, y en ambas técnicas se determinó el número de implantes, tamaño (<3, entre 3–7 y >7mm) y localización lobular. Resultados: Comparado con los resultados de la necropsia, en ecografía se detectaron lesiones en el 64% de los animales con patología. Todas las masas extrahepáticas fueron correctamente diagnosticadas. Se identificaron metástasis en el 90% de ratas afectadas por lesiones>7mm, en el 75% de animales con implantes de 3–7mm y en el 25% con lesiones<3mm. Con la sonda de 6–18Mhz se detectaron el 50% de lesiones

Objective: To determine the ultrasonographic characteristics of liver metastases induced in a rat model; to evaluate the usefulness of ultrasonography in the noninvasive evaluation of tumor infiltration. Material and methods: We seeded the livers of 46 WAG/RijCrl rats with CC-531 syngeneic colorectal carcinoma cells by intrasplenic inoculation. At 21, 28, 35, 42, 70 days after tumor seeding, we performed a series of ultrasonographic examinations to evaluate tumor induction in different groups of animals: 37 rats were studied with a 10MHz linear probe and 9 were studied with a 6–18MHz multifrequency probe. The following signs were considered indicative of tumor development: intrahepatic nodules, sinuate liver borders, lobe enlargement, and extrahepatic masses. Ultrasonographic findings were verified at autopsy. We determined the number of implants, size (less than 3mm, between 3 and 7mm, or greater than 7mm), and lobe location for each technique. Results: Compared to the autopsy results, ultrasonography detected 64% of the animals with disease. All the extrahepatic masses were correctly diagnosed. Metastases were identified in 90% of the rats with lesions greater than 7mm, in 75% of those with implants between 3 and 7mm, and in 25% of those with lesions less than 3mm. In the group in which we used the 6–18 MHz probe, we detected 50% of the lesions less than 3mm.ConclusionUltrasonography was useful for monitoring the experimental model and enabled the noninvasive oncologic evaluation of the rat liver with reasonable sensitivity (AU)

[Ultrasonographic characterization of an experimental model of liver metastases from colon carcinoma in rats]. / Caracterización ecográfica de un modelo experimental de metástasis hepáticas de carcinoma de colon.

OBJECTIVE: To determine the ultrasonographic characteristics of liver metastases induced in a rat model; to evaluate the usefulness of ultrasonography in the noninvasive evaluation of tumor infiltration. MATERIAL AND METHODS: We seeded the livers of 46 WAG/RijCrl rats with CC-531 syngeneic colorectal carcinoma cells by intrasplenic inoculation. At 21, 28, 35, 42, 70 days after tumor seeding, we performed a series of ultrasonographic examinations to evaluate tumor induction in different groups of animals: 37 rats were studied with a 10 MHz linear probe and 9 were studied with a 6-18 MHz multifrequency probe. The following signs were considered indicative of tumor development: intrahepatic nodules, sinuate liver borders, lobe enlargement, and extrahepatic masses. Ultrasonographic findings were verified at autopsy. We determined the number of implants, size (less than 3mm, between 3 and 7 mm, or greater than 7 mm), and lobe location for each technique. RESULTS: Compared to the autopsy results, ultrasonography detected 64% of the animals with disease. All the extrahepatic masses were correctly diagnosed. Metastases were identified in 90% of the rats with lesions greater than 7 mm, in 75% of those with implants between 3 and 7 mm, and in 25% of those with lesions less than 3mm. In the group in which we used the 6-18 MHz probe, we detected 50% of the lesions less than 3mm. CONCLUSION: Ultrasonography was useful for monitoring the experimental model and enabled the noninvasive oncologic evaluation of the rat liver with reasonable sensitivity.