[en] PURPOSE: To examine the role of positron emission tomography (PET) with labeled fluorodeoxyglucose (FDG) in patients with primary neoplasms of the head and neck. MATERIALS and METHODS: Between (9(92)) and (9(94)), forty-four FDG PET scans were performed on 27 patients with head and neck neoplasms. FDG uptake at the tumor sites was quantified with standardized uptake values (SUV). There were seven women and 20 men. Median age was 70 (37 - 85). All patients had squamous cell carcinoma except two with esthesioneuroblastoma. In six patients the primary site was occult and treatment consisted of surgery followed by radiation. In the other patients, primary sites included nasopharynx (2), base of tongue (6), tonsil (4), larynx (2), piriform sinus (3) paranasal sinuses (3) and multiple (1). Three were Stage II, four were Stage III, 11 were Stage IV and three had recurrent disease. Gross disease was treated by radiation (2), twice daily radiation (8) or concurrent chemotherapy and radiation (11). The median follow-up of survivors is 12 months (6 - 30). RESULTS: All patients had baseline scans prior to radiation therapy. In the six patients with occult primaries, no primary lesions were discovered by PET scans. In the other 21 patients, all known primary sites, regional node metastases and distant metastases demonstrated increased uptake on PET imaging. In one patient distant metastases were suggested on PET (but without corroborating clinical or radiographic evidence) and in two patients additional regional node metastases were discovered. Eleven patients had PET scans at the conclusion of radiation therapy. Five patients had complete responses by PET, two had major responses and four had partial responses. However, all these patients had good clinical responses and none have failed locally. Five patients had six scans during follow-up (at 3 to 12 months) to differentiate radiation changes from persistent disease. In four patients the PET scans were negative and they are all NED. The fifth patient (esthesioneuroblastoma) had a negative scan 8 months after treatment followed by a positive scan 4 months later. However, surgical exploration and biopsy revealed no disease. CONCLUSIONS: Our sample size is somewhat small but suggests the following. (1) For head and neck neoplasms, PET imaging is sensitive for both loco-regional and distant disease and may be useful in patients who are equivocally staged by conventional studies. (2) In patients with occult primary disease, PET scanning seems not helpful. (3) Positive PET scans immediately following radiation do not seem to predict local failure. (4) PET imaging may be of assistance in following non-surgically treated patients and may allow the elimination of some hazardous post-radiation biopsies