Disclosed are therapeutic methods for the treatment of disease material involving administration of a thermotherapeutic magnetic composition, which contains single-domain magnetic particles attached to a target-specific ligand, to a patient and application of an alternating magnetic field to inductively heat the thermotherapeutic magnetic composition. Also disclosed are methods of administering the thermotherapeutic magnetic material composition. The thermotherapeutic methods may be used where the predetermined target is associated with diseases, such as cancer, diseases of the immune system, and pathogen-borne diseases, and undesirable targets, such as toxins, reactions associated with organ transplants, hormone-related diseases, and non-cancerous diseased cells or tissue.