[18F-FDG imaging by coincidence circuit SPECT with low-dose CT in preoperative assessment of pulmonary lesions].
OBJECTIVE
To assess the clinical diagnostic value of 18F-FDG imaging by coincidence circuit SPECT with low-dose CT in differential diagnosis of pulmonary lesions and mediastinal lymph node involvement, which can not be definitely diagnosed based on regular CT image in patients with non-small-cell lung cancer (NSCLC).


METHODS
By using GE-Millennium VG with Hawkeye, 18F-FDG imaging was carried out in 48 patients with suspected lung cancer. Clinical value of 18F-FDG imaging for diagnosing malignancy was evaluated through comparison with the final pathological results. Mediastinal lymph node involvement was also assessed through lesion-by-lesion comparison with pathologic results in 74 lymph node regions from 24 patients.


RESULTS
Final pathologic diagnoses of these patients were 36 malignancies consisting of 20 adenocarcinomas, 12 squamous cell carcinomas, 3 small cell carcinomas and I large cell carcinoma; 12 benign tumors including 6 pneumonias, 2 tuberculosis, 2 hamatomas, 1 cyst and 1 neurofibroma. Of 48 patients, uptake of 18F-FDG in the chest was found to be abnormal in 40. Correct diagnosis were made in 34 malignancies and 6 false positive lesions were excluded based on morphology and 18F-FDG uptake status of the lesion. There were 6 false positive and 2 false negative cases. Furthermore, extrathoracic metastases which were not showed on previous CT image in 4 patients including one in the adrenal gland and 3 in the bone were detected by 18F-FDG imaging. The sensitivity, specificity and accuracy of the 18F-FDG imaging for differentiating malignant tumor from benign was 94.4%, 50.0% and 83.3%, respectively. Squamous cell carcinoma was found to uptake more FDG than adenocarcinoma. For determination of mediastinal lymph node involvement, the sensitivity, specificity and accuracy of 18F-FDG imaging was 57.9% , 90.9% and 82.4%, respectively through lesion-by-lesion comparison; whereas, which was 61.5%, 81.8% and 70.8%, respectively, based on case-by-case comparison.


CONCLUSIONS
18F-FDG imaging by coincidence circuit SPECT with low-dose CT is quite helpful in differential diagnosis for patient with undetermined lesion on regular CT image, but it is limited for staging of lung cancer in the patients with non-small cell lung cancer.
Wang
Qian
Q
Department of Nuclear Medicine, People's Hospital, Beijing University, Beijing 100044, China.
Huang
Li-Li
LL
Yue
Ming-Gang
MG
Qin
Shu-Ling
SL
Wang
Yu
Y
Nie
Yu-Xin
YX
Zhang
Cai-Qun
CQ
Liang
Tie-Jun
TJ
Zhao
Ya-Mei
YM
D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011014:Pneumonia / Q000175:diagnosis* / Q000000981:diagnostic imaging; D011300:Preoperative Care; D011829:Radiation Dosage; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014057:Tomography, X-Ray Computed; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000000981:diagnostic imaging
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18