Development of a Multimodal Tumor Model for Porcine Liver

Abstract

In our efforts to develop a guidance system for laparoscopic liver surgery, we are working towards a live animal tumor model. The objective of this study was to establish the tumor model for live porcine liver, visible on both computed tomography (CT) and ultrasound images. The tumor model was created by injecting a mixture of agarose, sephadex, and glycerol. Together with water, the mixture was heated to bring its components into solution. Once heating was complete, methylthionine chloride and CT contrast were added. Using laparoscopic ultrasound guidance, the tumor model mixture was injected into in vivo porcine liver. The resulting model tumors were radiolucent, visible on both CT and conventional X-ray. They appeared as hyperechoic lesions on ultrasound images. Compared to the CT images, the model tumors in the ultrasound images showed good correspondence in size. We conclude that our tumor model, due to its clearly identifiable nature on multiple imaging modalities, is a valuable tool for further studies on laparoscopic ultrasound (2D and 3D) and navigated ultrasound in laparoscopic surgery of the liver and other organs in a pre-clinical set-up.

Improving Echo-Guided Procedures Using an Ultrasound-CT Image Fusion System

“…[3][4][5]7 A step forward was made by Rethy et al, 6 who slightly modified the mix used to develop a multimodal tumor model, which was also visualized on CT scan.…”

“…The absence of a biological liver tumor model in large animals has driven several groups to develop synthetic tumors to simulate liver lesions. [3][4][5][6][7][8] When it comes to human pathology, synthetic tumors are clearly irrelevant to assess the efficacy of molecular targeted therapies or chemotherapy/chemoembolization. On the other hand, these injectable tumors can be helpful in verifying the accuracy of navigation systems and/or the precision of image-guided percutaneous or transcutaneous energybased ablative techniques.…”

“…An US-detectable mix of agarose, cellulose, glycerol, and methylene blue, injected in the liver of pigs, has been used as a training model and to evaluate accuracy of US-guided RF or high-intensity focused ultrasound. [3][4][5]7 A step forward was made by Rethy et al, 6 who slightly modified the mix used to develop a multimodal tumor model, which was also visualized on CT scan.…”