An apparatus and method particularly useful in treatments and therapies directed at the kidneys such as the prevention of radiocontrast nephropathy (RCN) arising from diagnostic procedures using iodinated contrast materials. A series of treatment schemes are provided based upon local therapeutic agent delivery to the kidneys that can be used as a prophylactic treatment for patients undergoing interventional procedures that have been identified as being at an elevated risk for developing RCN as well as for low risk patients. The methods may include pre-exposure and post contrast exposure treatments alone or in combination with the local delivery of therapeutic agents to the kidneys. Among the agents identified for such treatments are normal saline and the vasodilators papaverine and fenoldopam mesylate and appropriate dosing is provided.