Analysis of glucose metabolism of (18)F-FDG in major depression patients using PET imaging: Correlation of salivary cortisol and α-amylase.

Current diagnosis of Major depressive disorder (MDD) depends on its clinical symptoms, not on the results of any laboratory examinations. Establishing biological markers for diagnosis of MDD is one of the most important problems to be solved in psychiatry practice. MDD patients (n=8) and a healthy control group (n=8) were recruited in this study. Hamilton Depression Rating Scale (HAM-D) assessments were completed and saliva samples were collected for assessments of salivary cortisol and salivary α-amylase (sAA). PET examination was performed. Salivary cortisol and sAA in the MDD patients group were significantly higher than the healthy control group (P<0.001). MDD patients showed lower glucose metabolism of 18F-FDG in Cingulate Gyrus (BA24), Superior Frontal Gyrus (BA6), Rectal Gyrus (BA11) and Orbital Gyrus (BA11/47) compared with the healthy control group. The severity of depression, salivary cortisol and sAA correlated negatively with regional glucose metabolism in Cingulate Gyrus (BA 24), Superior Frontal Gyrus (BA 6), Rectal Gyrus (BA 11) and Orbital Gyrus (BA 11/47). The combination of salivary cortisol, sAA, superior frontal gyrus and rectal gyrus was the potential predictor of depression for MDD patients (ΔR(2)=0.981, p<0.001). The present study showed that, MDD patients group showed higher salivary cortisol, sAA levels and lower glucose metabolism of (18)F-FDG in several brain areas compared with the healthy control group. The combination of salivary cortisol, sAA, glucose metabolism of (18)F-FDG of superior frontal gyrus and rectal gyrus may serve as a simple clinical tool for the early diagnosis of MDD.

Association of pro-inflammatory cytokines, cortisol and depression in patients with chronic obstructive pulmonary disease.

Evidence suggests that pro-inflammatory cytokines and cortisol play a crucial role in the etiology of chronic obstructive pulmonary disease (COPD) and depression. Depression occurs commonly among COPD patients and an earlier diagnosis would be beneficial. This study investigated the associations between depression, sputum cytokines and salivary cortisol in COPD patients. The diurnal rhythms of sputum IL-1, IL-6, TNF-α and salivary cortisol were measured in COPD patients with depression compared to those only with depression, or COPD and healthy controls. The area under the diurnal variation curves (AUC) over the 24h time course and relative diurnal variation (VAR) were calculated while correlation and regression analysis were performed. Patients with co-morbid depression and COPD showed an increasing sputum IL-1, sputum TNF-α AUC and a decreasing salivary cortisol VAR (P<0.001). The combination of sputum TNF-α AUC, sputum IL-1 AUC, sputum IL-6 AUC and salivary cortisol VAR performed best as a potential biomarker in the diagnosis of depression in COPD patients, with a sensitivity of 94.74% and a specificity of 96.67%. Positive correlations were found between sputum IL-1 AUC and sputum TNF-α AUC versus depressive symptoms, respectively a negative correlation was found between salivary cortisol VAR and depression. They were independently associated with depression in logistic regression models. Depression in COPD is associated with higher 24-h overall levels of sputum IL-1, TNF-α and flattened diurnal salivary cortisol. These non-invasive sputum and salivary biomarkers may serve as a simple clinical tool for the early diagnosis of depression in COPD patients.

Flavonoid components in Scutellaria baicalensis inhibit nicotine-induced proliferation, metastasis and lung cancer-associated inflammation in vitro.

The objective of the present study was to investigate the therapeutic efficacy of flavonoid components in Scutellaria baicalensis on proliferation, metastasis and lung cancer-associated inflammation during nicotine induction in the A549 and H1299 lung cancer cell lines. After experimental period, augmentation of proliferation was observed, accompanied by marked decrease in apoptotic cells in nicotine-induced lung cancer cells; additionally, nicotine-exposed cells exhibited increased invasive and migratory abilities based on invasion and wound-healing assay. Flavones in Scutellaria, baicalin, baicalein and wogonin significantly counteracted the above deleterious changes. Moreover, assessment of tumor apoptotic and metastatic factors on mRNA levels by quantitative PCR and protein levels by western blotting revealed that these phytochemical treatments effectively negated nicotine-induced upregulated expression of bcl-2, bcl-2/bax ratio, caspase-3, matrix metalloproteinase (MMP)-2 and MMP-9 as well as downregulated expression of bax. Further analysis of inflammatory markers such as tumor necrosis factor (TNF)-α and interleukin (IL)-6 in cell culture supernatant and mRNA and protein expression of nuclear transcription factor-kappaB (NF-κB) and I kappa B-alpha (IκB-α) was carried out to substantiate the anti-inflammatory effect of flavones in Scutellaria in nicotine-exposed lung cancer cells. The therapeutic effects observed in the present study are attributed to the potent potential against proliferation, metastasis and inflammatory microenvironment by flavonoid components in Scutellaria in nicotine-induced lung cancer cells.

Sputum interleukin-6, tumor necrosis factor-α and Salivary cortisol as new biomarkers of depression in lung cancer patients.

Depression is common among lung cancer patients. Increasing evidence has suggested that hypothalamic-pituitary-adrenal (HPA) axis and pro-inflammatory cytokines may play a key role in the pathophysiology of depression as well as cancer. This pilot study investigated the efficacy of sputum interleukin (IL)-6, tumor necrosis factor (TNF)-α and salivary cortisol as new markers to support the diagnosis of depression in lung cancer patients. The diurnal rhythms of sputum IL-6, sputum TNF-α and salivary cortisol were measured in lung cancer patients with and without depression as well as depressed controls and healthy controls. The area under the diurnal variation curves (AUC) over the 24h time course and relative diurnal variation (VAR) were calculated. Receiver operating characteristic (ROC) analysis was performed. Patients with co-morbid depression and lung cancer showed highest level of sputum IL-6 AUC, sputum TNF-α AUC and lowest level of cortisol VAR (P<0.001). As a biomarker for depression, salivary cortisol VAR demonstrated an optimal cutoff point at 77.8% (AUC=0.94; 95% CI, 0.85-0.98), which is associated with a sensitivity of 82.1% and a specificity of 96.0%. Sputum IL-6 AUC demonstrated a sensitivity of 74.4% and a specificity of 92.0% (AUC=0.81; 95% CI, 0.69-0.90). These findings suggested that higher 24h overall levels of sputum IL-6, TNF-α and flattened diurnal salivary cortisol slopes were associated with depression in lung cancer patients. Sputum IL-6 AUC and salivary cortisol VAR performed best as biomarkers in the diagnosis of depression in lung cancer patients.

Airway inflammation and hypothalamic-pituitary-adrenal axis activity in asthmatic adults with depression.

OBJECTIVE: To investigate the features of airway inflammation and hypothalamic-pituitary-adrenal axis (HPAA) activity in patients with asthma accompanied by depression. METHODS: Adult asthmatics were recruited and enrolled into one of the two groups based on scores on the Hamilton Depression Rating Scale (HAMD): asthmatics with depression (HAMD score ≥8, n = 23), and asthmatics without depression (HAMD score <8, n = 41). In addition, 27 healthy individuals and 21 adults with depression only were enrolled as controls. Induced sputum and blood samples were collected for measurement of cytokines and other inflammatory factors. The diurnal rhythm profiles of salivary cortisol and other hormones were obtained for assessment of the HPAA activity. RESULTS: For the group of asthmatics with depression, the mean HAMD score was 19.0, and for the group of asthmatics without depression, the HAMD score averaged 4.9(p < .001). Serum and sputum tumor necrosis factor alpha (TNF-α) were significantly higher in asthmatics with depression than those in the other groups (p < .05) while serum interferon-gamma (IFN-γ) was lower in asthmatics with depression than that in the other groups (p < .05). Twenty-four-hour urinary cortisol, salivary cortisol at 8 a.m. and 4 p.m. were lower in asthmatics with depression compared to other groups (p < .05). CONCLUSIONS: As compared to healthy individuals and those with asthma or depression alone, individuals with comorbid depression and asthma showed the highest level of pro-inflammatory cytokines and the lowest level of anti-inflammatory cytokines and cortisol. These observations may serve as a valuable reference for diagnosis and clinic therapies of depression in asthmatics.

Impact of psychosocial stress on airway inflammation and its mechanism in a murine model of allergic asthma.

BACKGROUND: It has already been recognized that psychosocial stress evokes asthma exacerbation; however, the mechanism of how stress gets inside the body is not clear. This study aimed to observe the impact of psychosocial stress on airway inflammation and its mechanism in the ovalbumin-induced asthmatic mice combined with social disruption stress. METHODS: Thirty-six male BALB/c mice were randomly divided into: control group, asthma group (ovalbumin-induced), asthma plus social disruption stress group (SDR), and SDR group. The open field video tracking system was used to assess animal behaviors. The invasive pulmonary resistance (RL) and dynamic lung compliance (cdyn) test system from Buxco was applied to detect pulmonary function. The enzyme-linked immunosorbent assay (ELISA) was utilized to determine OVA-IgE, T-helper type 2 (Th2) cytokines (IL-4, IL-5, IL-13) and corticosterone in mouse serum, the Th2 cytokines (IL-4, IL-5, IL-13, IL-6, TNF-α) in bronchoalveolar lavage fluid (BALF), and IL-6 and TNF-α levels in the supernatant of splenocytes cultured in vitro. Hematoxylin-eosin (H&E) staining was used to assess airway inflammation in lung histology. The cell count kit-8 assay (CCK-8) was applied to evaluate the inhibitory effect of corticosterone on splenocyte proliferation induced by lipopolysaccharide (LPS). Real time-PCR and Western blotting were utilized to determine glucocorticoid receptor (GR) mRNA and GR protein expression in lungs. RESULTS: The open field test showed that combined allergen exposure and repeated stress significantly shortened the time the mice spent in the center of the open field (P < 0.01), increased ambulatory activity (P < 0.01) and the count of fecal boli (P < 0.01), but deceased vertical activity (P < 0.01). Results from pulmonary function demonstrated that airway hyperresponsiveness (AHR) was enhanced by psychosocial stress compared with allergy exposure alone. The ELISA results showed that cytokines in serum and BALF were significantly increased (P < 0.05). Moreover, the lung histology showed that infiltrated inflammatory cells were significantly increased in the asthma-SDR group compared with the asthma group (P < 0.05). Interestingly, serum corticosterone was remarkably raised by psychosocial stress (P < 0.05). In addition, the inhibitory effect of corticosterone on IL-6 and TNF-α in LPS-stimulated splenocyte cultures in vitro was diminished in the asthma-SDR group compared to the asthma group. The CCK-8 test revealed that the inhibition effect of corticosterone on splenocyte proliferation induced by LPS was significantly impaired in the SDR and asthma-SDR groups, while no significant effect was observed in the control and asthma groups. Furthermore, expression of GR mRNA and GR protein were significantly reduced in the lung tissues of the asthma-SDR group (P < 0.05). CONCLUSIONS: Social disruption stress can promote anxiety behavior, activate the hypothalamic-pituitary-adrenal (HPA) axis, increase AHR and inflammation, and also impair glucocorticoid sensitivity and its function in a murine model of asthma. The down-regulation of GR expression induced by social disruption stress is in part associated with glucocorticoid insensitivity, which leads to asthma exacerbation.

[Study on the correlation between the inflammatory factors in the serum and the induced sputum and the hypothalamic-pituitary-adrenal axis function in advanced lung adenocarcinoma of different syndromes].

OBJECTIVE: To study the correlation between the inflammatory factors in the serum and the induced sputum and the hypothalamic-pituitary-adrenal (HPA) axis function in advanced lung adenocarcinoma patients of different syndromes. METHODS: Totally 71 patients with advanced lung adenocarcinoma were assigned to three groups according to syndrome differentiation, i.e., Shen-yang deficiency (SYD) group (28 cases), Fei-qi deficiency (FQD) group (23 cases), and yin deficiency fire excess (YDFE) group (20 cases). Another 41 healthy subjects were enrolled as the normal control group. Sputum was induced and blood samples were collected for measurement of cytokines including tumor necrosis factor alpha (TNF-alpha), transforming growth factor beta (TGF-beta), interleukin-6 (IL-6), and interferon gamma (INF-gamma). The cytokine assay was performed using Bio-Plex Pro multi assay technology. 24-h collection of urine was performed and salivary samples of the diurnal rhythm profiles [including urinary free cortisol (UFC), urinary 17-hydroxycorticosteroids (17-OH), urinary 17-ketosteroid (17-KS), and cortisol in the serum and saliva] were obtained for assessment of the HPA axis activity. RESULTS: A higher level of serum IL-6 and a lower level of 24-h UFC and 17-OH were found in the SYD group (P < 0.05). The urinary 17-KS was obviously lower in the SYD group than in the normal control group and the YDEE group (P < 0.05). Compared with the FQD group and the normal control group, a higher serum level of TNF-alpha and a lower level of IFN-gamma were found in the SYD group and the YDFE group (P < 0.05). The TNF-alpha and TGF-beta levels in the induced sputum obviously increased in the SYD group (P < 0.05). The IFN-gamma level in the induced sputum obviously decreased in the YDFE group (P < 0.05). The serum and salivary cortisol obviously decreased from 8: 00 am to 8:00 am the next morning in the SYD group (P < 0.05). The serum cortisol level was negatively correlated with serum TNF-alpha (r = -0.26, P = 0.03) and serum IL-6 (r = -0.25, P = 0.03). The salivary cortisol level was negatively correlated with IL-6 in the induced sputum (r = -0.29, P = 0.02). The serum IFN-gamma was positively correlated with urinary 17-OH (r = 0.21, P = 0.03). CONCLUSIONS: The inflammatory factors of advanced lung adenocarcinoma patients of SYD syndrome were up-regulated, with the most obvious decreased or disarranged HPA axis functions. The levels of IL-6, TNF-alpha, and IFN-gamma were closely correlated with the HPA axis functions. The transformation from qi deficiency, yin deficiency to Shen-yang deficiency existed in lung adenocarcinoma patients. The levels of IL-6, TNF-alpha, and IFN-gamma in the serum and the induced sputum, as well as the HPA axis functions are important indices for microscopic syndrome typing of lung adenocarcinoma.

Molecular mechanism of icariin on rat asthmatic model.

BACKGROUND: Effects of icariin on airway inflammation in asthmatic rats and the intervention of LPS induced inflammation are interfered with the machanism of icariin. Our study aimed to observe the effect of icariin on ovalbumin-induced imbalance of Th1/Th2 cytokine expression and its mechanism. METHODS: Sixty male SD rats were randomly divided into control group (PBS), asthma group (ovalbumin (OVA)-induced), dexamethasone group, and OVA+icariin low, medium and high dose groups (5, 10, 20 mg/kg, respectively). Each group had ten rats. The model of OVA sensitization was a rat asthma model. Enzyme-linked immunosorbent assay (ELISA) method was used to observe the effects of icariin on interleukin-4 (IL-4) and inerferon γ (IFN-γ) in rats' lung tissue. Immunohistochemical staining was applied to detect the intervention effects of icariin on T cells (T-bet) and gatabinding protein 3 (GATA-3) in rat pulmonary tissue. Realtime RT-PCR was used to observe the intervention effects of icariin on T-bet and GATA-3 mRNA expression in rat pulmonary tissue and spleen lymphocytes. Western blotting was used to observe the icariin intervention effects on T-bet, GATA-3 and nuclear factor-Kappa B (NF-κB) p65 protein expressions in rat pulmonary tissue. RESULTS: The ELISA results from pulmonary tissue showed that IL-4 expression was significantly reduced (P < 0.05), while the IFN-γ expression increased but not significantly when we compared OVA+icariin medium and high dose groups with the asthma group. Immunohistochemical staining of pulmonary tissue showed that the GATA-3 decreased significantly while the T-bet staining did not change in the OVA+icariin high dose group. In pulmonary tissue and spleen lymphocytes T-bet and GATA-3 mRNA expressions were significantly reduced (P < 0.05) in icariin treatment groups compared with the asthma model group. GATA-3 and T-bet mRNA in rat spleen lymphocytes in the asthma group were higher than in the control group. GATA-3 mRNA expression in pulmonary tissue significantly decreased (P < 0.05) while T-bet mRNA expression decreased but not significantly in the icariin treatment group compared with the asthma group. T-bet and GATA-3 protein expressions in pulmonary tissue increased significantly compared with the asthma group, which meant that icariin could inhibit the increase of GATA-3 protein, but not of T-bet. The bronchus, blood vessels and periphery pulmonary tissue had infiltration of inflammatory cells in the OVA+icariin high dose group while NF-κB p65 cells were reduced, and expression of NF-κB p65 in this group was less than in the asthma group. The expression of total p65 protein decreased with icariin treatment while the expression of cytoplasmic p65 protein increased. CONCLUSIONS: Icariin could regulate the imbalance of Th1/Th2 cytokines in asthmatic rat pulmonary tissue. Icariin could regulate the imbalance of Th1/Th2 associated transcription factors T-bet and GATA-3 in asthmatic rat pulmonary tissue and spleen lymphocytes. Icariin could inhibit the activation of NF-κB p65 protein in asthmatic rat pulmonary tissue.

[Biomarkers and inflammatory characteristics for microcosmic syndrome differentiation of cold-phlegm syndrome and heat-phlegm syndrome in patients with bronchial asthma].

OBJECTIVE: To explore the biomarkers and inflammatory characteristics for microcosmic syndrome differentiation of cold-phlegm syndrome (CPS) and heat-phlegm syndrome (HPS) in patients with bronchial asthma. METHODS: Patients with bronchial asthma of chronic persistent condition were distributed into three groups according syndrome differentiation, the CPS group (27 patients), the HPS group (32 patients) and the non-cold/heat-phlegm syndrome group (NP group, 31 patients), besides, a control group was setup with 33 healthy persons. Percentages of neutrophils and eosinophils (NEU, EOS) in sputum sample (collected by induction) and peripheral blood were counted; and levels of interleukin-8, -5, and -4 (IL-8, IL-5 and IL-4), interferon-gamma (IFN-gamma), leukotriene B4 (LT-B4), eosinophil cationic protein (ECP), and C-reactive protein (CRP) in sputum supernatant and serum were determined by enzyme-linked immunosorbent assay. RESULTS: Percentage of NEU in sputum of HPS group was higher than that in the other three groups (P < 0.05); while percentages of EOS in serum and sputum of CPS group were higher than that in the other three groups (all P < 0.01). Level of ECP (a parameter closely associated with EOS) also was high in the CPS group, but IL-8 (a parameter closely associated with NEU) showed no significant difference in various groups (P > 0.05). Moreover, the CPS group showed a higher serum IL-4 (P < 0.05) but a lower IFN-gamma/IL-4 level as compared with those in the NP group (P < 0.01). CONCLUSION: Phlegm, which is considered by Chinese medicine as an inveterate root of asthma, might be closely related with the inflammation in modern medicine. The inflammatory characteristics of asthma in patients with CPS partially present as increase of EOS, possibly show Th2 dominant trend, similar to that presented in eosinophilic asthma. Asthma with HPS embodies increase of NEU in respiratory tract. EOS and ECP might be the important markers for microcosmic syndrome differentiation of CPS, and NEU might be that for HPS.

Inflammatory airway features and hypothalamic-pituitary-adrenal axis function in asthmatic rats combined with chronic obstructive pulmonary disease.

BACKGROUND: Bronchial asthma (BA) and chronic obstructive pulmonary disease (COPD) are both inflammatory airway diseases with different characteristics. However, there are many patients who suffer from both BA and COPD. This study was to evaluate changes of inflammatory airway features and hypothalamic-pituitary-adrenal (HPA) axis function in asthmatic rats combined with COPD. METHODS: Brown Norway (BN) rats were used to model the inflammatory airway diseases of BA, COPD and COPD + BA. These three models were compared and evaluated with respect to clinical symptoms, pulmonary histopathology, airway hyperresponsiveness (AHR), inflammatory cytokines and HPA axis function. RESULTS: The inflammatory airway features and HPA axis function in rats in the COPD + BA model group were greatly influenced. Rats in this model group showed features of the inflammatory diseases BA and COPD. The expression of inflammatory cytokines in this model group might be up or downregulated when both disease processes are present. The levels of corticotrophin releasing hormone mRNA and corticosterone in this model group were both significantly decreased than those in the control group (P < 0.05). CONCLUSIONS: BN rat can be used as an animal model of COPD + BA. By evaluating this animal model we found that the features of inflammation in rats in this model group seem to be exaggerated. The HPA axis functions in rats in this model group have been disturbed or impaired, which is prominent at the hypothalamic level.

Icariin attenuates LPS-induced acute inflammatory responses: involvement of PI3K/Akt and NF-kappaB signaling pathway.

This study aimed to investigate the mechanism underlying the attenuation of LPS-induced lung inflammation by icariin in vivo and in vitro. The anti-inflammatory effects of icariin on LPS-induced acute inflammatory and the molecular mechanism were investigated. Pretreatment with icarrin (20mg/kg) could attenuate acute lung inflammation by inhibiting mRNA expressions of tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), metalloproteinase cycloxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) in the lung of LPS-treated mice. In addition, icariin suppressed the secretion of TNF-alpha, prostaglandin E2 (PGE(2)) and nitric oxide (NO) as well as NF-kappaB p65 activation. Furthermore, decreased myeloperoxidase (MPO) activity was observed in the lung tissue and LPS-induced cytotoxicity in the RAW 264.7 macrophages cells was also markedly attenuated by icariin. Western blotting analysis and confocal microscopy showed that icariin pretreatment reduced the nucleus transportation and constant level of NF-kappaB p65 in the RAW 264.7 macrophage cells. However, the protective effects of icariin were reversed by a PI3K/Akt inhibitor (wortmannin). Our in vitro and in vivo results suggested that activation of the PI3K/Akt pathway and the inhibition of NF-kappaB were involved in the protective effects of icariin on LPS-induced acute inflammatory responses.

[Feature of airway inflammation in asthmatic rats complicated with chronic obstructive pulmonary disease and effect of Chinese herbs for reinforcing Shen and supplementing qi on it].

OBJECTIVE: To observe the airway inflammatory change in asthmatic rats complicated with chronic obstructive pulmonary disease (COPD) and to assess the intervention effects of Chinese herbs for reinforcing Shen and supplementing qi (CH) on it. METHODS: Eighty-four Norway rats were randomized into 7 groups, the normal control group (A), the COPD model group (B), the asthma model group (C), the combined COPD and the asthma model group (D), and the three CH treated groups (E, F and G, combined model rats administered by low-, moderate- and high- dose CH, respectively), 12 rats in each group. Changes of symptoms, pathologic changes of the lung tissue, airway reactivity, and serum levels of interleukin-4, interleukin-6, interleukin-8 (IL-4, IL-6, and IL-8) and interferon-gamma (IFN-gamma) in rats were observed. RESULTS: Symptoms were alleviated in the three CH treated groups. Similar pathological features were shown in group B and D, showing inflammatory cell, mainly lymphocyte, infiltration in bronchial and lung tissues, with cilia denudation, partial alveolar wall rupture, alveolar cavity expansion, and accompanied with evident eosinophilic infiltration. These inflammatory exudation in group E-G was alleviated, while in group C, it developed showing a trend similar to that in group D. Airway resistance raised along with the concentration of Mch used. In group D, the serum level of IL-4 was higher than that in group B, and level of INF-gamma was lower than that in group A, B and C (all P <0.05). CH showed a lowering effect on serum levels of IL-4 and -8, and a dose-dependent rising effect on IFN-gamma. CONCLUSIONS: IL- 4 significantly increased and INF-gamma decreased in rat model of combined COPD and asthma, its mechanism is similar to that of Th1/Th2 imbalance in asthma. Chinese herbs for reinforcing Shen and supplementing qi could improve the symptoms and inhibit the airway inflammation in the combined COPD and asthma model rats, its mechanism might be related with the alleviation of TH1/TH2 imbalance.

Accuracy of 18F-FDG PET/CT for lymph node staging in non-small-cell lung cancers.

BACKGROUND: This retrospective study evaluated the diagnostic accuracy of 2-(F18)-fluoro-2-deoxy-D-glucose-positron emission tomography ((18)F-FDG-PET)/computed tomography (PET/CT) in the preoperative diagnosis of metastatic mediastinal and hilar lymph node in patients with non-small-cell lung cancer (NSCLC). METHODS: A total of 39 patients received preoperative (18)F-FDG PET/CT and the postoperative biopsy. We compared preoperative PET/CT scan results with corresponding intraoperative histopathalogic findings in 39 NSCLC patients. The sensitivity, specificity, accuracy, positive and negative predictive value of (18)F-FDG PET/CT were assessed. RESULTS: Histopathologic examination confirmed metastasis in 57 out of the 208 excised lymph nodes; 23 of the 57 nodes were mediastinal and hilar lymph nodes. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of PET/CT in the preoperative diagnosis of mediastinal lymph node metastasis in NSCLC patients were 65%, 96.8%, 92%, 78.5% and 90%, respectively. CONCLUSIONS: PET/CT scan showed good accuracy in the preoperative diagnosis of mediastinal and hilar lymph node metastasis in the patients with NSCLC. We recommend that PET/CT scanning be used as a first-line evaluation tool for tumor diagnosis, therapy evaluation and follow-up.