Systems and methods are disclosed for directing magnetizable particles comprising therapeutic agents to a target volume, or for guiding magnetizable particles comprising therapeutic agents from a first target volume to a second target volume, at a distance using a magnetic field, to enable the treatment of diseased areas including areas deep inside a patients body. The methods may be used to diagnose or treat diseased areas within a patient, for example tumors of the lungs, intestines, and liver, and is also useful in enhancing the permeability of solid tumors to chemotherapeutic agents.