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Objective@#To investigate the predictive value of 18F-FDG PET-CT scan for occult lymph node metastasis in patients with stage ⅠA lung adenocarcinoma.@*Methods@#The image and pathological data of 272 patients with stage ⅠA lung adenocarcinoma from October 2006 to September 2015 were retrospectively analyzed. All patients underwent preoperative 18F-FDG PET-CT scan followed by lobectomy and systematic lymph node dissection. The correlation between occult lymph node metastasis and the maximum standardized uptake value (SUVmax) of primary tumor as well as other clinicopathological factors was analyzed to screen the risk factors of occult lymph node metastasis in stage ⅠA lung adenocarcinoma.@*Results@#Occult lymph node metastasis was detected in 50 patients (18.4%), with 24 (8.8%) patients of pN1 involvement and 26 (9.6%) of pN2 involvement. Among the 272 patients enrolled, 39 had pure ground glass nodule, 59 had part-solid nodule and 174 had solid nodule. All patients with pure ground glass nodule or nodule≤1 cm were pN0. For the 233 patients with part-solid and solid nodule, no lymph node metastasis was found in T1a stage (tumor length ≤1 cm). Primary tumor SUVmax (Z=-5.663, P<0.001), nodule type (χ2=21.586, P<0.001), tumor location (χ2= 12.790, P< 0.001), histological grade (χ2= 22.784, P< 0.001) and visceral pleural invasion (χ2=5.357, P=0.021) showed significant differences between occult lymph node metastasis group (pN+ ) and non-lymph node metastasis group (pN0). With SUVmax=2.405 as cut-off value, the sensitivity and specificity for predicting occult lymph node metastasis were 90.0% and 61.7%, the area under curve was 0.761(95%CI=0.700~0.823), and the negative predictive value was 95.8%. Multivariate analysis revealed that SUVmax >2.405 (P<0.001), central location (P=0.030) and higher histological grade (P=0.024) were independent predictors of occult lymph node metastasis.@*Conclusions@#For clinical stage ⅠA adenocarcinoma, primary tumor SUVmax > 2.405, central location and higher histological grade were independent risk factors for occult lymph node metastasis. Systematic lymph node dissection may be avoided in lung adenocarcinoma with pure ground glass density, tumor length ≤1 cm or SUVmax ≤ 2.405, due to the very low probability of nodal involvement.
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Objective To investigate the value of DWI using 3.0 T MRI to predict response to radiotherapy(RT) and concurrent chemoradiotherapy(CCRT) in patients with advanced non-small cell lung cancer (NSCLC).Methods From January 2014 to May 2015, 40 patients with stageⅢ(Ⅲa orⅢb) NSCLC underwent DWI using 3.0 T MRI before RT/CCRT were enrolled. The imaging quality of diffusion-weighted images were evaluated on 3-level grades as good, moderate and non-diagnostic.The patients with good or moderate image quality were underwent DWI at 2 weeks after starting therapy(total dose of 20 Gy), and at the end of therapy (total dose of 60 Gy). Apparent diffusion coefficient(ADC) of lung cancer with good and moderate image quality were calculated by Funtool. The following quantitative parameters were recorded and calculated: the mean pretreatment ADC value(ADCpre), the mean mid-treatment ADC value (ADCmid), the mean post-treatment ADC value(ADCpost), the rate of changes inmean ADC value at 2 weeks post therapy (ΔADCmid) and the rate of changes inmean ADC value at the end of therapy(ΔADCpost). The patients were classified into response group and non-response group according to the tumor response, which was assessed with revised response evaluation criteria in solid tumors (RECIST1.1) after CCRT. The Mann-Whitney U test was used to compare parameters between the two groups.The relationship between these obtained parameters and tumor response was evaluated by Spearman correlation analysis. The value of parameters on predicting tumor response was calculated by receiver operating characteristic curve.Results 96.4%(80/83) DW images were graded as good or moderate image quality. The responders had lower median ADCpre[1.32 (0.77—1.96) × 10- 3 mm2/s] than non-responders[1.60(1.12—2.33) × 10- 3 mm2/s], which had statistically significant difference (Z=-2.934,P=0.003).Tumor regression rate after treatment had negative correlation with ADCpre(r=-0.386, P=0.018).The responders had increased ADC [ΔADCmid: 38.9%(12.8%—139.0%),ΔADCpost: 48.3% (25.6%—148.1%)] than non-responders [ΔADCmid: -2.5% (-15%—29.4%), ΔADCpost:14.2% (- 28.1% —71.3% )], which had statistically significant difference (Z=- 2.847, - 2.221, respectively;P<0.05). Tumor regression rate after treatment had positive correlation with ΔADCmid(r=0.637, P=0.001) and ΔADCpost(r=0.631, P=0.005).From ROC analysis,when setting threshold on pretreatment ADCpre=1.38 × 10-3 mm2/s, ΔADCmid=21.6%, ΔADCpost=38.8%, the area under curve was 0.782, 0.838 and 0.813.Conclusion The mean ADC value before RT/CCRT and its changes during treatment is likely to be a valuabletool for predicting the response after RT/CCRT in advanced NSCLC, which may be helpful to clinical decision on individualized therapy.
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<p><b>OBJECTIVE</b>To evaluate the high resolution CT (HRCT) features of cyst-like lung adenocarcinoma, explore the correlation between HRCT image features and histopathological characteristics, and observe the pathological basis of air-containing space.</p><p><b>METHODS</b>HRCT and histopathologic findings of cyst-like lung adenocarcinoma in 86 patients were investigated retrospectively. The image features of both tumor and air-containing space were analyzed. All surgically resected specimens were reviewed. The pathological analysis included histologic subtype, differentiation degree, and the pathological basis of air-containing space formation. The correlation between HRCT image features and histopathologic grades was analyzed.</p><p><b>RESULTS</b>On HRCT, intratumoral necrosis was detected in 17 cases (19.8%), air-containing space with septa in 40 cases (46.5%), wall nodule in the air-containing space in 16 cases (18.6%), mixed thick and thin walls of air-containing space in 49 cases (57.0%). Air-containing space and its wall were observed in 63 cases on histological specimens, among which destruction of the alveolar wall by tumor cells might be the pathological basis of air-containing space in 42 (66.7%) cases. Differences of tumor attenuation (P = 0.030), intratumoral necrosis (P = 0.003) and proportion of thin-wall in air-containing space (P = 0.014) among different histopathologic grades were significant. The proportion of thin-wall in air-containing space was negatively correlated with histological grade (r = 0.267, P = 0.015). Differences of tumor contour (P = 0.002), tumor attenuation (P = 0.006), intratumoral necrosis (P < 0.001), septa in air-containing space (P = 0.016) and proportion of thin-wall in the air-containing space (P = 0.005) among different differentiation degrees were significant. The proportion of thin-wall in air-containing space was positively correlated with differentiation degree (r = 0.266, P = 0.013).</p><p><b>CONCLUSIONS</b>On HRCT, cyst-like lung adenocarcinoma may manifest as an air-containing space with septa and mixed thin and thick walls, whereas wall nodule of air-containing space and intratumoral necrosis are not common. There is a certain correlation of HRCT manifestation with pathological subtype grading and tumor differentiation. Analysis of HRCT image features is helpful in prediction of the histopathologic grading and histological differentiation degree of the tumors. Destruction of the alveolar structure by tumor cells may be the main pathological basis of air-containing space formation in cyst-liked lung adenocarcinoma.</p>