Real-time Targeted Fluorescence Endoscopy for Detection of the Primary Cancer Lesion in Patients With a Metastasis of Unknown Primary Tumor in the Head and Neck

Inclusion Criteria:

* Cytology and/or histology-confirmed diagnosis of squamous cell carcinoma most likely originating from the head \& neck area and scheduled to undergo endoscopy of the upper aerodigestive tract as decided by the multidisciplinary head and neck tumor board of the UMCG;
* The primary tumor was not identified during standard diagnostic work-up in the outpatient clinic including physical head and neck examination, fiberoptic laryngoscopy, chest X-ray, CT and PET/CT;
* Age ≥ 18 years;
* Written informed consent;

Exclusion Criteria:

* Medical or psychiatric conditions that compromise the patient's ability to give informed consent;
* Concurrent uncontrolled medical conditions;
* Received an investigational drug within 30 days prior to the dose of cetuximab-800CW;
* History of myocardial infarction, cerebrovascular accident, uncontrolled cardiac heart failure, significant liver disease (ALT \>3X upper limits of normal or increased total bilirubin) or unstable angina within 6 months prior to enrollment;
* Inadequately controlled hypertension with or without current antihypertensive medications;
* History of allergy or infusion reactions cetuximab or other monoclonal antibody therapies;
* Pregnant or lactating women. Documentation of a negative pregnancy test must be available for women of childbearing potential. Moreover, the need to be willing to ensure that she or her partner uses effective contraception during the trial and for 6 months thereafter. Woman of childbearing potential are premenopausal women with intact reproductive organs and women less than two years after menopause;
* Evidence of QT prolongation on pretreatment ECG (greater than 440 ms in males or greater than 450 ms in females)
* Patients receiving Class IA (quinidine, procainamide) or Class III (dofetilide, amiodarone, sotalol) antiarrhythmic agents.
* Life expectancy \< 12 weeks;
* Karnofsky performance status \< 70%.