Administrative reasons.

The purpose of this research is to assess the safety and evaluate the potential of the Multispectral Optoacoustic Tomography (MSOT) device to more precisely identify and assess the neck lymph nodes which might be affected in patients with metastatic head and neck squamous cell carcinomas.

This is a 2-Arm investigational device study designed to provide safety information regarding the use of the Acuity MSOT device in the clinical setting, and to determine the ability of MSOT imaging data to correlate with clinical findings identified via pathology. Imaging with the MSOT device is expected to obtain information about the number, size, and appearance of the lymph nodes in the neck. The device will be used to obtain images of the tumor or lymph node margins for investigational use only to compare to clinical pathology and patient's medical records. All images will be obtained pre-surgery for Arm 1 patients (undergoing surgery for their cancer) and before, during and after radiotherapy in Arm 2 patients (undergoing radiotherapy treatment for their cancer). The temperature of the patient's skin will also be measured prior to and after each MSOT scan. Once radiotherapy treatment has completed, images using the MSOT device will be obtained every 6 months for 2 years to assess for radiation induced fibrosis. MSOT scans will be for research only and no treatment decisions will be based on the MSOT images obtained.

Inclusion Criteria:

• Clinically confirmed node positive head and neck squamous cell cancer
• Written informed consent signed and dated by the patient prior to the performance of the MSOT
• At least 18 years-of-age at the time of signature of the informed consent form (ICF)
• Patients planned for curative intent therapy
• Patient available for the study duration
• Patients of childbearing potential must have a negative pregnancy test prior to the study entry.
• Patients of childbearing potential must use an effective form of contraceptive as per the protocol.

Exclusion Criteria:

• History of previous head and neck radiotherapy
• Intent of treatment palliative
• Women who are pregnant
• Patients with a prior or concurrent malignancy whose natural history or treatment does not have the potential to interfere with the safety of efficacy assessment of the investigational regimen should be included.
• Psychological, familial, sociological, or geographical conditions that do not permit compliance with the protocol and/or follow-up procedures outlined in the protocol.