“…Thus, ionizing radiation can achieve not only direct cancer cell death but also has an indirect and systemic anti-tumor mechanism outside of the irradiated field, which has been reported in some clinical settings (Antoniades, et al, 1977,Ehlers and Fridman, 1973,Kingsley, 1975,Nobler, 1969,Perego and Faravelli, 2000,Rees, 1981,Rees and Ross, 1983,Sham, 1995. Local irradiation resulted in an anti-tumor effect at a non-irradiated location in a patient with hepatocellular carcinoma that regressed after palliative local radiotherapy for pain control of bone metastases (Ohba, et al, 1998).…”