Investigating the Effect of Size and Site of Implantation on Tumour Vascular Morphology and Function Using Combined Carbogen USPIO (CUSPIO) Imaging

Jake Samuel Burrell¹, Jane Halliday², Simon Walker-Samuel³, John C. Waterton², Jessica Boult¹, Yann Jamin¹, Lauren C. Baker¹, Simon P. Robinson¹

Tumour vascular morphology and function is dependent on both tumour size and site of implantation. Perturbation of tissue R₂* by carbogen gas (95% O2, 5% CO2) breathing, or ultra small paramagnetic iron oxide (USPIO) particle injection offers biomarkers for tumour oxygenation, and blood volume respectively. Using a combined carbogen USPIO imaging protocol, tumour δR₂* during carbogen breathing, and after injection of USPIO particles was found to be significantly different in small and large subcutaneous, and orthotopic PC3 prostate tumours. This has implications when considering both drug delivery, and extent of tumour oxygenation during drug trials