The goal of this work was to develop and validate a pancreas tumor animal model to investigate the relationship between photodynamic therapy (PDT) effectiveness and photosensitizer drug delivery. More specifically, this work lays the foundation for investigating the utility of dynamic contrast enhanced blood perfusion imaging to be used to inform subsequent PDT. A VX2 carcinoma rabbit cell line was grown in the tail of the pancreas of three New Zealand White rabbits and approximately 3-4 weeks after implantation the rabbits were imaged on a CT scanner using a contrast enhanced perfusion protocol, providing parametric maps of blood flow, blood volume, mean transit time, and vascular permeability surface area product.
Conventional CT imaging methods lack the accuracy that is necessary for detailed assessment of liver metastasis. However, quantitative measurement of hepatic perfusion has the potential to provide important information necessary for both the evaluation and treatment of liver metastasis. VX2 carcinoma cells were injected into the liver of healthy male rabbits. A two-phase scan protocol was used to acquire CT images for the determination of liver perfusion prior to and post implantation. Contrast enhancement curves from the aorta, portal vein and liver parenchyma were obtained from the reconstructed images. The weighted summation of the aortic and portal venous curve were de-convolved against the liver parenchymal curve to derive functional parameters such as total hepatic blood flow (HBF) and hepatic arterial fraction (HAF). Results show that the HAF of the implanted tumor increased throughout the period of the study. Twelve days after tumors were implanted the HAF in the liver significantly increased (P < 0.05) from the normal tissue value of 35 ± 1 to 57 ± 9 %. Functional maps of the HAF have the potential to improve treatment outcome of patients owing to the earlier diagnosis of liver cancer. We are able to detect VX2 tumors in the liver as early as 8 days after they were implanted.