18F-FDG PET for the lymph node staging of non-small cell lung cancer in a tuberculosis-endemic country: is dual time point imaging worth the effort?
OBJECTIVE
This study was to compare (18)F-FDG positron emission tomography (PET) with thoracic contrast-enhanced CT (CECT) in the ability of lymph node (LN) staging non-small cell lung cancer (NSCLC) in a tuberculosis-prevalent country. The usefulness of dual time point PET imaging (DTPI) in NSCLC nodal staging was also evaluated.


METHODS
We reviewed 96 NSCLC patients (mean age, 65.3+/-11.7 years) who had received PET studies before their surgery. DTPI were performed on 37 patients (mean age, 64.8+/-12.2 years) who received an additional scan of thorax 3 h after tracer injection. The accuracies of nodal staging by CECT and PET were evaluated according to final histopathology of hilar and mediastinal LN resected by surgery.


RESULTS
The accuracy for nodal staging by CECT was 65.6% and that by PET was 82.3% (p<0.05). Six patients were over-staged and 11 were under-staged by PET. Tuberculosis (n=3, 50%) were mostly responsible for false-positive, while small tumor foci (n=7, 63.6%) were mostly accountable for false-negative. For the 37 patients with DTPI, 45 min standardized uptake value (SUV) and 3 h SUV for negative LNs are significantly lower than those for positive LNs (p<0.0001). Nevertheless, the retention index (RI) showed no significant difference between these two groups.


CONCLUSIONS
Our study demonstrates that PET is more accurate than CECT in LN staging NSCLC patients in Taiwan where TB is still prevalent. Semi-quantitative SUV method or DTPI with RI does not result in better diagnostic accuracy than visual analysis of PET images.
Yen
Ruoh-Fang
RF
Department of Nuclear Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
Chen
Ke-Cheng
KC
Lee
Jang-Ming
JM
Chang
Yeun-Chung
YC
Wang
Jane
J
Cheng
Mei-Fang
MF
Wu
Yen-Wen
YW
Lee
Yung-Chie
YC
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000150:complications / Q000000981:diagnostic imaging* / Q000556:secondary*; D005189:False Positive Reactions; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000150:complications / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D013624:Taiwan; D014057:Tomography, X-Ray Computed; D014397:Tuberculosis, Pulmonary / Q000150:complications
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18