[PET scan in tumor diagnosis in the head and neck]

PET, a new method in nuclear medicine, allows the in vivo measurement of tumor metabolism and tumor perfusion. Absolute and standardized PET data can be used for comparative examinations before, during and after therapy. It thereby is possible to assess very early the efficacy of a therapy and also to change the therapeutic scheme. Furthermore PET studies with multiple parameters allow the evaluation of the biological behaviour of the tumor and yield information that is relevant for prognosis.