Diagnosis efficacy of structural (CT) and functional (FDG-PET) imaging methods in the thoracic and extrathoracic staging of non-small cell lung cancer.
OBJECTIVE
To evaluate the efficacy of FDG-PET in the definition of tumour lung node lesions and to compare the diagnostic validity of CT and FDGPET in the staging of patients with non-small cell lung cancer (NSCLC).


METHODS
Patients with clinical suspicion of potentially resectable NSCLC (n = 108) were studied by standard procedures in our setting, including fibrobronchoscopy, transthoracic fine-needle aspiration, thoracoabdominal CT and FDG-PET. PET images were analysed by researchers blinded to results of other imaging modalities. Definitive tumour diagnosis was by histopathological study in patients who underwent surgery and by specific imaging methods and biopsy, when available, in patients who did not. Diagnostic accuracy was evaluated by comparing CT/PET results with the definitive diagnosis.


RESULTS
In 13% of patients, no FDG-PET findings were observed and the histological study was negative for tumour. In 22% of patients, FDG-PET detected metastatic disease (M0 by CT). For mediastinal involvement, global diagnostic accuracy was 0.90 with FDG-PET and 0.59 with CT. False positive FDG-PET findings were produced by inflammatory conditions and false negative findings by the small size or proximity of lymph nodes to primary tumour. Mediastinal staging by CT and FDG-PET was correct in 56% and 87% of patients, respectively. CT indicated mediastinal invasion in 17% of patients with no FDG-PET finding of mediastinal involvement. Conversely, mediastinal spread was undetected by CT in 14% of patients with FDG-PET findings of mediastinal involvement.


CONCLUSIONS
Although complementary, the functional method (FDG-PET) is significantly superior to the structural method (CT) for detection of mediastinal tumour disease.
Rodríguez Fernández
Antonio
A
Servicio de Medicina Nuclear, Hospital Universitario Virgen de las Nieves, Granada,, Spain. antonio.rodriguez.f.sspa@juntadeandalucia.es
Gómez Río
Manuel
M
Llamas Elvira
José Manuel
JM
Sánchez-Palencia Ramos
Abel
A
Bellón Guardia
María
M
Ramos Font
Carlos
C
Torné Poyatos
Pablo
P
Pedraza Muriel
Vicente
V
D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18