Radiation therapy, along with surgery and chemotherapy, are the major therapeutic strategies for cancer treatment. It involves the delivery of ionizing radiation with high accuracy to the tumor tissue, resulting in the death of tumor cells. Radiation sensitization is a process of enhancing the susceptibility of tumor tissues to injury by radiation exposure. Hence, radiation sensitizers are therapeutic or otherwise inert agents that enhance the effects of radiation therapy. Iron oxide nanoparticles, a type of magnetic nanoparticle (MNP), are amongst the nanomaterials which have been suggested as radiation sensitizers (Figure 1). 1 Hyperthermia is a type of cancer treatment in which tissue is exposed to elevated temperatures. Hyperthermia is almost always used with other forms of cancer therapy, such as radiation therapy and chemotherapy. Hyperthermia may make some cancer cells more sensitive to radiation. When hyperthermia and radiation therapy are combined, they are often given within an hour of each other. MNP can induce localized hyperthermia when exposed to an alternating magnetic field (AMF). 3,4 As MNP are potentially capable of producing two sensitization effects (x-ray interaction and hyperthermia generation) they are particularly attractive for this application.