C-11 methionine PET and 18-F FDG-PET for identifying recurrent laryngeal carcinoma

Preservation of the larynx is an important goal in the treatment of laryngeal cancer. Laryngeal cancer is therefore usually treated with radiotherapy. The recurrence rate after therapy is on an average 30%. The differentiation between radiation reactions may be difficult. A biopsy under general anesthesia with all its negative consequences for the patient is the gold standard to confirm a recurrence. During the last decades several studies have been published which indicate that [18F]FDG-PET may detect recurrent laryngeal cancer. Our study shows that [18F] FDG -PET is an alternative for a traditional work-up, although the number false positive results remains high. We searched for alternatives to [18F] FDG. The alternative we have tested [11C] methionine reduced the number of false positive results. On the other hand the number of false negative results inclined. [11C]MET is no alternative to [18F] FDG.