A method of treatment of a diseased patient in which a dose of at least one heavy metal is delivered to the patient, with a surface area which is accessible for direct contact with the patient's tissue and effects release of heavy metal ions for uptake by immuno reactive cells. The criteria to be complied with in order for the heavy metal to be effective is that the surface area is greater than the surface area of a solid sphere of the same at least one heavy metal, and that the solid sphere and dose have the same weight. In a preferred embodiment, the dose of heavy metals is delivered to the patient as very small hollow particles.