The maximum standardized uptake value of 18F-FDG PET/CT combined with the image features on high resolution CT for the diagnosis of lung cancer

Abstract

Objective To investigate the diagnostic value of the SUVmax of 18F-FDG PET/CT combined with the image features on high resolution CT(HRCT) for lung cancer.Methods 18F-FDG PET/CT and HRCT data of 122 patients with pulmonary tumor-like lesions from August 2010 to August 2011 were analyzed retrospectively.Diagnoses of the subjects were confirmed by pathology or follow-up (＞ 8 months).x2 test was performed to compare the differences in the constituent ratio of different HRCT features of the lesions.One-way analysis of variance was used to evaluate the differences of SUVmax in different pathological types of lung cancer.Multivariate logistic stepwise regression analysis was performed to evaluate the significance of SUVmax and HRCT features for diagnosis of lung cancer.Results Out of the 122 patients,there were 40 with benign lesions and 82 with malignant lesions.Spiculation sign (64.6％,53/82),lobulation sign (63.4％,52/82) and pleural indentation sign (39.0％,32/82) were the top three HRCT features of the pulmonary malignant tumors,higher than those of benign lesions (x2 =19.08,30.89,10.88,all P ＜0.01).There was a statistical difference of SUVmax between benign (3.01 ± 3.62) and respective type of malignant lesions (F =20.83,P ＜ 0.01).SUVmax of squamous cell carcinoma,small cell carcinoma and adenocarcinoma was 12.57 ± 4.34,10.66 ± 2.90 and 8.19 ± 6.01 respectively.There was a statistical difference of SUVmax between adenocarcinoma and squamous cell carcinoma (P ＜0.01).The AUC on ROC curves of SUVmax was 0.863.The sensitivity,specificity and Kappa value were 89.0％ (73/82),75.0％(30/40),0.644 with a SUVmax cutoff of 2.99 and 91.5％ (75/82),65.0％ (26/40),0.597 with a SUVmax cutoff of 2.50 for malignant lesion,respectively.Multivariate logistic stepwise regression analysis showed that OR for SUVmax 2.99 was higher than OR for SUVmax 2.5 (5.42 vs 3.93).SUVmax (OR =5.42,P =0.01),tumor maximal diameter (OR =7.27,P =0.02),spiculation sign (OR =7.70,P ＜ 0.01) and lobulation sign (OR =12.38,P ＜ 0.01) were the significant parameters in differential diagnoses of lung cancer.Conclusions SUVmax is valuable in the diagnosis of lung cancer.Combination of SUVmax and HRCT may improve the diagnostic capabilities for lung cancer.SUVmax,tumor maximal diameter,spiculation sign and lobulation sign are the significant parameters or features for image interpretation. Key words: Lung neoplasms; Tomography, emission-computed; Tomography, X-ray computed ; Deoxyglucose