In search of an unknown primary tumour presenting with cervical metastases: performance of hybrid FDG-PET-CT.
OBJECTIVE
In patients with cervical lymph node metastases from unknown primary tumour (UPT), the primary tumour is frequently localized in the head and neck area. Because the detection of the primary tumour is of importance to optimize the patient's management and allows a targeted therapy, the performances of hybrid positron emission tomography-computed tomography (PET-CT) using fluorodeoxyglucose (FDG) were evaluated in a retrospective study.


METHODS
Thirty-eight consecutive patients with cervical lymph node metastases, and in whom the primary was not detected by the comprehensive diagnostic work-up including endoscopy and conventional imaging methods, were referred for a PET-CT scan.


RESULTS
PET-CT was positive with an increased FDG focal uptake suggesting the potential primary site in 68% of patients (26/38), which guided the biopsies during a second rigid panendoscopy in 17 of these 26 patients: 13 primary tumours were then histologically proven. PET-CT showed distant lesions in three patients. It had treatment-related implications in 23/38 patients (60%), consisting of modification of radiation planning, surgery or abstention from surgery.


CONCLUSIONS
Hybrid FDG-PET-CT is helpful for the detection of a potential head and neck primary tumour. Furthermore, hybrid FDG-PET-CT has the ability to diagnose occult or distant second tumour and metastatic disease and modify patient management.
Wartski
Myriam
M
Nuclear Medicine Department of Cancer Research Center Rene Huguenin, Saint-Cloud, France. m.wartski@stcloud-huguenin.org
Le  Stanc
Elise
E
Gontier
Eric
E
Vilain
Didier
D
Banal
Alain
A
Tainturier
Catherine
C
Pecking
Alain Paul
AP
Alberini
Jean Louis
JL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging; D005260:Female; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009382:Neoplasms, Unknown Primary / Q000175:diagnosis*; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed / Q000379:methods*
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18