[FDG-PET-CT based imaging of retropharyngeal lymph nodes with its impact on radiotherapy]. / Die Darstellung retropharyngealer Lymphknoten in der FDG-PET/CT und ihre Bedeutung für die Radiotherapie.

BACKGROUND: In about 20% there is an involvement of the retropharyngeal lymph nodes in patients with locally advanced carcinoma of the hypopharynx and cervical esophagus. A case report should demonstrate the diagnostic and therapeutic impact of FDG-PET/CT in the radiotherapeutic management of a locally advanced carcinoma of the hypopharynx in special consideration of the RPLN. PATIENT AND METHOD: A pretherapeutic FDG-PET/CT was performed with the patient fixed in the radiotherapy mask in order to integrate the anatomic and metabolic information into the radiotherapy planning system by an exact matching of the data. RESULTS: Only the FDG-PET could detect a retropharyngeal lymph node involvement (RPLN) by an intensive glucose utilisation with a consecutive modification of the target volume and dose increase in this region. CONCLUSION: This case report demonstrates that FDG-PET/CT facilitates the imaging of metabolic active and otherwise hardly detectable lymph nodes in locally advanced head and neck cancer with consequences on target volume definition and dose application in radiotherapy.