Chemotherapy medications can be delivered directly to the blood supply of a tumour allowing a possible increase in the effectiveness of the drugs.
What is intra-arterial chemotherapy?
Traditional chemotherapy is administered through a catheter into a peripheral vein. This means the chemotherapy drug has to pass via the heart and lungs before being delivered to the cancer, and therefore the drug is diluted by the time it reaches the target. If we deliver the chemotherapy directly into an artery as close to the tumour as possible we can maximise the amount of chemotherapy delivered to the cancer cells and therefore possibly increase the effectiveness of our treatment.
How is intra-arterial chemotherapy delivered?
The arteries commonly used for intra-arterial chemotherapy are the femoral arteries in the hind legs and the carotid arteries in the neck. The artery is exposed via a small incision and a catheter placed. Under fluoroscopy (live video x-rays) tiny wires and catheters are advanced through the arterial system to reach the vessel supplying blood directly to the tumour. The chemotherapy drug can then be delivered very close to the tumour itself.
This is an image of a dog with bladder cancer and highlights us mapping the blood supply to the bladder, prostate and local lymph nodes in order to deliver the chemotherapy directly the tumour rather than through the intravenous route. Early work has shown this allows significantly higher doses of the chemotherapy to reach the cancer.
What is the benefit of intra-arterial chemotherapy?
Intra-arterial chemotherapy allows selective delivery of high doses of chemotherapy directly to the tumour. Intra-arterial (IA) administration allows significantly greater concentrations of chemotherapy to reach the tumour without the side effects that would be encountered had an equivalent intravenous dose been used to achieve the same local chemotherapy concentrations. Experimental studies in dogs have documented the improved effectiveness of these techniques in achieving higher local concentrations and improved tumour remission rates for certain types of tumours.
What tumours can be treated with intra-arterial chemotherapy?
While most investigatory work has been performed in liver tumours, urinary tumours (bladder, prostate and urethra) and osteosarcomas (bone tumours) there are a wide range of cancers which are likely to benefit from intra-arterial administration of chemotherapy.