Management of cervical lymph node recurrence of melanoma of the head and neck

To compare the diagnostic accuracy between Positron emission tomography using 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG-PET scan) and conventional work-up such as ultrasound (US) and/or Computed tomography (CT) in the detection of cervical lymph node recurrences of melanoma of the head and neck after initial cervical lymph node surgery.

A retrospective review was performed on patients who presented with clinical and/or radiological suspicion of isolated cervical lymph node recurrence after lymph node surgery from April 2004 to January 2007. All patients underwent CT and/or US of the neck, and FDG-PET scan before salvage neck dissection. None of included patients had clinical or radiological detectable distant metastases at the time of the lymph node dissection. Performances of conventional imaging and FDG-PET scan in detection of lymph node recurrence were calculated and compared by using the histopathological results of lymphadenectomy as gold standard with Fischer's exact test.

Of the twelve cases in included in the study (9 patients, 3 of them had 2 consecutive lymph node redissection for a second lymph node recurrence), melanoma recurrence was found in 10 cases (83%). Sensitivity, specificity, positive predictive value and negative predictive values were 78.6%, 40%, 78.6%, and 40% respectively for conventional imaging and 85.7%, 40%, 80% and 50% for FDG-PET scan. No statistically significant difference was found between the 2 methods.

This is the first study that compares the diagnostic accuracy between FDG-PET scan and conventional imaging in the detection of cervical lymph node recurrence of melanoma of the head and neck. Our results showed that FDG-PET scan is actually not better than conventional imaging to detect these cervical lymphatic recurrences.