2[F]-fluoro-2-deoxy-D-glucose positron emission tomography is a sensitive tool for the detection of occult primary cancer (carcinoma of unknown primary syndrome) with head and neck lymph node manifestation.
BACKGROUND
The neck lymph nodes are a common site of metastases from carcinoma of unknown primary (CUP syndrome). 2[(18) F]-fluoro-2-deoxy-D-glucose positron emission tomography (18-FDG-PET) has been shown to be a sensitive tool for detecting primary malignant lesions as well as metastatic spread. We have prospectively investigated the sensitivity of 18-FDG-PET in detecting occult primary carcinomas with manifestation in the head and neck lymph nodes.


METHODS
From May 1994 to July 1998, in 723 patients a cancer of the head and neck was diagnosed at the University of Cologne ENT outpatient clinic. The routinely performed staging procedures were chest radiography; full blood count; cervical and liver ultrasound; endoscopy of the nasopharynx, oropharynx, hypopharynx, larynx, and esophagus; and laboratory analyses. After the staging workup, in 27 of 723 patients (3.7%) CUP syndrome had to be presumed because the primary cancer could not be detected. In these patients 18-FDG-PET was performed, and images were reconstructed with a transmission-emission fusion technique.


RESULTS
In 7 of 27 patients (26%) 18-FDG-PET revealed an unknown primary: in 2 a bronchial carcinoma, in 2 a nasopharyngeal carcinoma, in 1 a squamous cell carcinoma of the parotid gland, in 1 a squamous cell carcinoma of the hypopharynx, and in 1 a carcinoma of the tonsil. In 4 of 7 patients the occult primary tumor was removed surgically. In 8 of 27 patients therapeutic strategy was changed as a result of the 18-FDG-PET findings.


CONCLUSIONS
18-FDG-PET should be performed in all patients with CUP syndrome after conventional diagnostic workup fails to identify the primary.
Jungehülsing
M
M
ENT and Nuclear Medicine Departments, University of Cologne, Germany.
Scheidhauer
K
K
Damm
M
M
Pietrzyk
U
U
Eckel
H
H
Schicha
H
H
Stennert
E
E
D000230:Adenocarcinoma / Q000556:secondary; D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000556:secondary*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000556:secondary*; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009382:Neoplasms, Unknown Primary / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D014055:Tomography, Emission-Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18