This study is being conducted in order to find out if this approach is as good as the usual approach in controlling the cancer and has fewer side effects and better quality of life. The usual approach for patients who are not in a study is treatment which includes radiotherapy to the tumour and to both sides of the neck to decrease the risk of spread or recurrence of the cancer
This study is being done to answer the following question:~Is the chance of cancer spreading or returning the same if radiotherapy to the neck is guided, by using a special imaging study called lymph node mapping (lymphatic mapping) Single Photon Emission Computed Tomography (SPECT-CT), compared to the usual treatment when radiotherapy is given to both sides of the neck?