Radiotherapy is the primary treatment for advanced head and neck cancer and this treatment is often compromised by cancer cells containing low levels of oxygen (hypoxia). We have discovered new examples of drugs that mimic oxygen and sensitise these hypoxic cells to radiotherapy (radiosensitisers). We will identify the best of these radiosensitisers to use in head and neck cancer. We will examine these drugs in human head and neck cell lines and use 3D cell cultures to determine their ability to diffuse to low oxygen regions of solid tumours. Drugs will be compared with the clinical radiosensitiser, nimorazole, as sensitisers of human tumours to stereotactic body radiotherapy (SBRT). SBRT is an emerging treatment that uses fewer, larger radiation doses and shortens treatment duration. Our longer term objective is to support first-in-human clinical trials of a radiosensitiser for in head and neck cancer in NZ .