A combination of an anti-cancer agent and a metal radiosensitizer potentiates the radiotherapy of cancer. Said anti-cancer agent is preferably cisplatin while the metal radiosensitizer is preferably gold nanoparticles. Both the anti-cancer agent and the metal radiosensitizer bind to DNA and potentiate the radiotherapy of cancer by synergistically increases the amount of double strand breaks induced by the radiation. The anti-cancer agent and the metal radiosensitizer may be encapsulated in liposomes.
