Phase II and III studies have demonstrated IMRT to be safe and standard practice for head and neck cancers treated with radiotherapy. This study will be an extension to an earlier, in-house, trial to allow continued recording of toxicities and outcomes in patients receiving IMRT for head and neck cancers. This study will allow us to examine radiobiological modelling for normal tissue complication probability and in particular, determining the dose threshold for parotid glands. Our primary objective is to assess the potential effectiveness of intensity-modulated radiotherapy (IMRT) in reducing xerostomia in head and neck cancer patients and determining threshold dose for whole parotid gland and superficial lobes of parotid glands

Inclusion Criteria:

• Histologically confirmed squamous cell cancer or undifferentiated cancer of nasopharynx, oropharynx, larynx and hypopharynx and squamous cell carcinoma unknown primary.
• TNM Stage: T1-4, N0-3 M0
• Patients requiring primary or postoperative radiotherapy to the primary site and bilateral neck irradiation requiring IMRT
• Parotid sparing IMRT feasible (parotids clear of malignant disease)
• WHO Performance status 0-1 (Karnofsky >80)
• Aged 18 or older
• Induction chemotherapy and concomitant platinum based chemotherapy is permitted
• Concomitant cetuximab is permitted where platinum chemotherapy is contraindicated
• All patients must be suitable to attend regular follow-up and salivary flow measurements and be available for long term follow up.
• All patients must be able to complete self-assessed quality of life questionnaire
• Be able to provide written informed consent

Exclusion Criteria:

• Previous radiotherapy to the parotid gland/s
• Pre-existing salivary gland pathology interfering with saliva production
• Previous or concurrent illness which in the investigator's opinion which will interfere with either completion of therapy or follow up
• Brachytherapy is not allowed as part of the treatment
• Presence of lymphadenopathy adjacent to or involving both parotid glands making whole parotid sparing or superficial parotid sparing impossible
• Prophylactic use of amifostine or pilocarpine is not allowed

Patients with histologically confirmed squamous cell cancer or undifferentiated cancer of nasopharynx, oropharynx, larynx and hypopharynx and squamous cell carcinoma unknown primary referred for primary or postoperative radiotherapy to the primary site and bilateral neck irradiation requiring IMRT