[PET/CT and PET/MRI in Head and Neck Cancer]

Positron emission tomography (PET) with ¹⁸F-fluordeoxyglucose (FDG) in combination with computed tomography (CT) is well established for the diagnostic work-up of patients with head and neck cancer. Possible applications include the detection of an occult primary tumor metastatic to cervical nodes, locoregional staging, assessment of treatment response to external beam irradiation (also in combination with chemotherapy), and surveillance for recurrence. The success of high-precision irradiation techniques such as intensity-modulated radiation therapy (IMRT) appears to be improved by delineating the tumor volume using PET/CT. Combined PET/Magnetic Resonance Imaging (MRI) offers advantages in staging with regard to increased anatomical details and radiation dose reduction but is inferior to PET/CT in the detection of pulmonary metastases and secondary tumors. As shown by a randomized trial in patients with advanced head and neck cancer, neck dissection can be omitted if FDG PET/CT is negative after radiochemotherapy and survival is not compromised. With this high level of evidence PET/CT in head and neck cancer currently found its way into the catalog of diagnostic procedures for patients in the statutory health insurances.