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BackgroundIntegrated 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is widely performed in hilar and mediastinal lymph node (HMLN) staging of non-small cell lung cancer (NSCLC). However, the diagnostic efficiency of PET/CT remains controversial. This retrospective study is to evaluate the accuracy of PET/CT and the characteristics of false negatives and false positives to improve specificity and sensitivity.Methods219 NSCLC patients with systematic lymph node dissection or sampling underwent preoperative PET/CT scan. Nodal uptake with a maximum standardized uptake value (SUVmax) >2.5 was interpreted as PET/CT positive. The results of PET/CT were compared with the histopathological findings. The receiver operating characteristic (ROC) curve was generated to determine the diagnostic efficiency of PET/CT. Univariate and multivariate analysis were conducted to detect risk factors of false negatives and false positives.ResultsThe sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET/ CT in detecting HMLN metastases were 74.2% (49/66), 73.2% (112/153), 54.4% (49/90), 86.8% (112/129), and 73.5% (161/219). The ROC curve had an area under curve (AUC) of 0.791 (95% CI 0.723-0.860). The incidence of false negative HMLN metastases was 13.2% (17 of 129 patients). Factors that are significantly associated with false negatives are: concurrent lung disease or diabetes (p<0.001), non-adenocarcinoma (p<0.001), and SUVmax of primary tumor >4.0 (p=0.009). Postoperatively, 45.5% (41/90) patients were confirmed as false positive cases. The univariate analysis indicated age > 65 years old (p=0.009), well differentiation (p=0.002), and SUVmax of primary tumor ≦4.0 (p=0.007) as risk factors for false positive uptake.ConclusionThe SUVmax of HMLN is a predictor of malignancy. Lymph node staging using PET/CT is far from equal to pathological staging account of some risk factors. This study may provide some aids to pre-therapy evaluation and decision-making.

The determinations of water status incorporated in hydrous minerals are of considerable significances in geoscience fields. Coincidentally, the aqueous sensitivity of terahertz radiation has motivated numerous explorations in several cross-domain applications. Terahertz time-domain spectroscopy is employed as a major probing technique coupling of traditional detecting methods to uncover the mask of water status in copper sulfate pentahydrate as well as mineral quartz in this article. Based on the quantitative identification of water status in copper sulfate pentahydrate, the water incorporated in mineral quartz is verified qualitatively. Notable differences of optical constants originating from the water content are obtained for copper sulfate pentahydrate and mineral quartz. These present works indicate that terahertz technology can be considered as a promising method to satisfy the ever-increasing requirements in hydrous mineral analyses.

Objectives-Pathological invasion level of extramammary Paget disease (EMPD) is strongly related with its risk staging, treatment, and prognosis. However, the current evaluation before treatments fails to evaluate pathological invasion level of EMPD. High-frequency ultrasound (HFUS) may play a key role to solve this problem. The purpose was to explore the performance of HFUS in the evaluation of pathological invasion level of EMPD.Methods-Sixty pathologically proven EMPD patients were retrospectively enrolled and divided into 2 groups as follows: in situ in the epidermis (IE) (n = 42) and invasion into the dermis or subcutaneous (ID) (n = 18) groups. Clinical and HFUS features were compared between the 2 groups.Results-Between the 2 groups, HFUS features (lesion shape, internal echogenicity and echotexture, surface shape, epidermal hyperechoic layer on the surface, the "pseudopod sign", and color Doppler ultrasound features) and clinical features were comparable (all P >.05). Tumor growth pattern significantly differed between the 2 groups (P <.05). Infiltration depth was significantly deeper for the ID group than the IE group (P <.05). With a cutoff value of 1.55 mm for infiltration depth, the area under the receiver operating characteristic curve was 0.833.Conclusions-HFUS features of tumor growth pattern and infiltration depth may contribute to the assessment of invasion level of EMPD.