Combined FDG PET/CT Imaging in Response Evaluation After Radiochemotherapy in Patients With Locally Advanced Head and Neck Squamous Cell Carcinoma (HNSCC) (ECLYPS)

• The sensitivity and specificity of high-resolution FDG PET/CT [ Time Frame: 12 weeks after chemoradiation ] [ Designated as safety issue: No ]
• The sensitivity and specificity of dual time point FDG PET/CT [ Time Frame: 12 weeks after chemoradiation ] [ Designated as safety issue: No ]
• The number of additional metastases found on PET and the % change in patient management [ Time Frame: Prior to start of chemoradiation ] [ Designated as safety issue: No ]
• DFS and OS, correlation with baseline SUV, early PET response and with HPV status [ Time Frame: 1 year after completion of chemoradiation ] [ Designated as safety issue: No ]

To determine if combined [18F]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) is performant enough with respect to detecting residual lymph node involvement after chemoradiation in order to omit planned neck dissections in patients with locally advanced potentially operable, N2 and N3 head and neck squamous cell carcinoma (HNSCC).

Primary study hypothesis: FDG PET/CT will have a negative predictive value (NPV) higher than 90% to detect residual malignant lymph node involvement at 12 weeks after completing chemoradiation.

Patients with locally advanced, N2 and N3 head and neck squamous cell carcinoma (HNSCC) will be recruited. All subjects receiving induction chemotherapy will undergo a baseline integrated [18F]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) scan before the start of concurrent chemoradiation. This baseline assessment is optional in patients not receiving neo-adjuvant treatment.

All patients will undergo a dedicated FDG PET/CT protocol 12 weeks after the end of chemoradiation (primary endpoint). In PET/CT negative patients, 2 monthly control visits will be performed complemented with additional imaging as required. All patients will undergo PET/CT 1 year after completing chemoradiation unless recurrent/residual disease was already proven pathologically. Patients with a PET/CT suspected for residual nodal disease must have pathological proof of nodal involvement (fine needle aspiration in non-operable patients or neck dissection in the others) before salvage chemotherapy is started.

In a subset of patients receiving induction chemotherapy prior to concurrent chemoradiation, an additional FDG PET/CT scan will be performed at baseline and after 1 cycle of chemotherapy to evaluate the metabolic response to the treatment (secondary endpoint).

Patients with locally advanced, N2 and N3 HNSCC

Inclusion Criteria:

• Patients with locoregionally advanced HNSCC (clinically and/or radiological N2 or N3 disease, any T stage) with no evidence of distant metastases, scheduled for concurrent chemoradiation and being potential candidates for a subsequent neck dissection.
• Induction chemotherapy is allowed if this approach is followed by concurrent chemo-radiation.

Exclusion Criteria:

• Other head and neck cancer histologies
• Upfront inoperable patients in the neck (eg. carotid invasion)
• Presence of distant metastases
• A history of another primary malignancy, except when disease-free for at least 5 years after radical treatment, or except for treated basaloid skin cancer or in situ carcinoma of the cervix