PET/CT: Role in Detecting Unknown Primary Head and Neck Cancer

The Clinical Utility of PET-CT in the Management of Squamous Cell Carcinoma of Neck Nodes With an Unknown Primary Malignancy.

Historically metastatic squamous cell carcinoma in a cervical lymph node from an occult primary malignancy of the head and neck was evaluated with panendoscopy and biopsies of high risk areas, such as the base of tongue, nasopharynx, and tonsils. This diagnostic protocol identifies the primary malignancy in about 50% of cases. In recent years, the availability of CT has slightly increased the detection rate to 65% when used as an adjunct to the traditional work-up. Studies using PET as an adjunct are conflicting with detection rates ranging up to 75%. Currently, no prospective study has analyzed the role of the PET-CT fusion in the work-up of an occult primary malignancy of the head and neck. This study will compare the detection rate of the traditional work-up to a new protocol involving a pre-operative diagnostic PET-CT.

Inclusion Criteria:

• Age > 18 years old
• Biopsy proven SCC in a cervical lymph node
• Unknown primary cancer after: History, Physical exam, and office endoscopy by otolaryngologist
• Negative Chest X-Ray for malignancy
• Patient consent signed to undergo investigative protocol

Exclusion Criteria:

• Un-fit for general anesthesia
• Unable to lie flat for 45 minutes
• Unable to fast for > 6 hours
• Unable to perform PET-CT (Obesity > 150kg)
• Pregnant
• Prior Head and Neck cancer
• Any invasive cancer (Non-Head and Neck) within the last 2 years