How Can We Overcome Tumor Hypoxia in Radiation Therapy?

Local recurrence and distant metastasis frequently occur after radiation therapy for cancer and can be fatal. evidence obtained from radiochemical and radiobiological studies has revealed these problems to be caused,at least in part,by a tumor-specific microenvironment,hypoxia. moreover,a transcription factor,hypoxia-inducible factor 1 (hif-1),was identified as pivotal to hypoxia-mediated radioresistance. to overcome the problems,radiation oncologists have recently obtained powerful tools,such as simultaneous integrated boost intensity-modulated radiation therapy (sib-imrt),which enables a booster dose of radiation to be delivered to small target fractions in a malignant tumor