FDG-PET in the pretherapeutic evaluation of primary squamous cell carcinoma of the oral cavity and the involvement of cervical lymph nodes.

Purpose: The diagnostic role of positron emission tomography (PET) with 2-deoxy-2-[18F]fluoro-D-glucose (FDG) in squamous cell carcinoma of the oral cavity is evaluated.

Procedures: In 38 patients, the results of FDG-PET, magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound were compared. The standard uptake values (SUV) of FDG-PET were correlated to histopathological grading and DNA-image cytometry.

Results: In the case of lymph node metastases, the sensitivity of FDG-PET (93%) was higher than the sensitivity for the compared methods. The specificity was best for CT. SUVs of diploid tumor cell lines seemed to be lower than in non-diploid tumor cell lines.

Conclusions: The high sensitivity and the high negative predictive value of PET may lead to more restrictive therapeutic regimens regarding lymph node metastases. Studies are necessary regarding possible relationships between glucose metabolism and tumor grading.