Inclusion Criteria:

All of the following criteria must be satisfied:

1. Histological evidence of squamous cell carcinoma of the head & neck (T1-T4 arising in
either the oral cavity, larynx & pharynx, except Nasopharyngeal carcinoma);OR
patients with histological evidence of squamous cell carcinoma metastatic to the neck
and an unknown primary site after conventional workup without any of the following:
i). Clinically suspected skin primary or previous diagnosis of skin cancer arising in
the head and neck area; ii). Patients of Asian or African decent -possible
nasopharynx primary; iii). Patients whose malignant adenopathy is confined to zone V
-possible nasopharynx primary; and iv). Patients whose malignant adenopathy is
confined to zone IV (supraclavicular)-possible lung primary.

2. Presence of advanced N2 or N3 neck disease.

3. Planned for primary curative radiation therapy (± chemotherapy) followed by neck
dissection eight to twelve weeks after completion of treatment.

Exclusion Criteria:

1. Presence of distant metastasis

2. Recurrent tumour

3. Prior neo-adjuvant chemotherapy

4. Previous radiation therapy to intended treatment volumes

5. Other active malignancy

6. Surgically inoperable neck disease

7. Unable to remain supine for 60 minutes

8. Unfit to undergo general anesthetic or neck dissection for medical reasons

9. Known hypersensitivity to CT contrast

10. Pregnancy