[Diagnostic value of dual-head 18F-FDG imaging in metastatic lesion with unknown primary tumour].
OBJECTIVE
To investigate the diagnostic value of dual-head (18)F-fluorodeoxyglucose ((18)F-FDG) imaging in metastatic lesion with unknown primary tumour (UPT).


METHODS
Seventy patients with UPT underwent dual-head (18)F-FDG imaging after iv (18)F-FDG 1.85 MBq/kg. The primary tumour was diagnosed according to the FDG uptake and T/N value.


RESULTS
Of the 70 patients, the primary tumour was identified by positive FDG imaging and finally confirmed pathologically in 58 patients (82.9%), and 12 patients had a negative FDG imaging (17.1%). Forty-two of the 58 positive patients were found to have lung cancer (72.4%). Among the 12 negative patients, their primary tumour was then identified by other diagnostic procedures in 5 patients (41.7%), in 1 patient, the primary site was detected during follow-up, however, the primary tumour was never detected in the rest 6 patients.


CONCLUSIONS
Dual-probe (18)F-FDG imaging is a simple, quick, non-invasive and sensitive technique with an accuracy over 80% in the diagnosis of unknown primary tumour. The lung is found to be the most frequent primary site. Dual-probe (18)F-FDG imaging can be recommended as the first diagnostic choice for UPT.
Pan
Yan-ji
YJ
Department of Radiatiion Oncology, First Foshan People's Hospital, Foshan 528041, China.
Wei
Guang-yu
GY
Feng
Yan-lin
YL
Yu
Feng-wen
FW
Liu
De-jun
DJ
Zhang
Ning
N
D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D009382:Neoplasms, Unknown Primary / Q000000981:diagnostic imaging* / Q000473:pathology; D049268:Positron-Emission Tomography
D019788:Fluorodeoxyglucose F18