PET in head and neck cancers

FDG PET is useful when cancer in the head or neck (except for tumors of the salivary glands, which cannot be characterized accurately) is diagnosed of suspected but not confirmed by biopsy It can for example, find evidence of suspicious lymph nodes in clinically No necks, detect foci suggestive of distant metastases of second cancers, and provide useful prognostic information. Because it con be very difficult to identify anatomical structures and landmarks on PET images in the head and neck region, PET/CT fusion is very helpful in this area. In early assessment of chemotherapy, the absence of a significant reduction in FDG uptake after one or two cycles predicts lock of efficacy and thus indicates the need to modify the regimen. Conversely the disappearance of FOG foci indicates effective treatment and good prognosis but cannot rule out the persistence of any malignant tissue at the end of treatment, especially neoadjuvant. Diagnostic impact is probably greatest in monitoring for recurrence and restaging known recurrence: FDG PET should be performed perhaps routinely - early enough that curative options ore still open, but long enough after the end of treatment to ovoid false positive results from inflammation. The strategy and timing of FD6 PET during follow-up should be determined in more detail in the future, as should the role (if any) of fluorotyrosine (FET) PET in squamous cell carcinoma.