The disclosed subject-matter relates to a method for treatment of a patient by irradiating a tumor by means of an irradiation device, the method comprising the steps of scanning at least a part of a body of the patient to generate a scan, said part comprising the tumor； localizing the tumor in the scan； determining a hypoxic and a normoxic region of the tumor in the scan； targeting only the hypoxic region for irradiation； and irradiating the targeted hypoxic region； wherein the normoxic region is not targeted for irradiation during the treatment. The disclosed subject-matter further relates to a system configured to carry out the method.
