| PET provides functional instead of anatomical information like conventional diagnostic techniques as CT and MRI. We performed pilot studies in HNSCC patients with diagnostic problems: detection of lymph node and distant metastases, the detection of an occult primary tumor and the detection of recurrent tumor. The detection of occult lymph node metastasis in the clinical negative neck is under investigation. In patients at risk for distant metastases and synchronous primary tumors the value of PET was slightly better than CT-thorax and may prevent unnecessary treatment. In patients with lymph node metastases of an unknown primary tumor PET was able to detect the primary tumor more often than CT- or MRI-scan of the neck and may prevent unnecessary wide field gamma-irradiation. PET was superior to CT and MRI in discrimination between recurrent laryngeal carcinoma and post-radiotherapy changes in patients with clinical suspicion on recurrent laryngeal carcinoma and may prevent unnecessary laryngoscopy. Currently efficacy studies are ongoing to develop diagnostic guidelines for HNSCC patients with aforementioned diagnostic problems to prevent unnecessary invasive diagnostic techniques and treatments. Multicenter studies on screening for distant metastases and synchronous second primary tumors below the clavicles and the detection of unknown primary tumors presenting as a metastases in the head and neck have been started. |
