| Part 1:Spectral parameters analysis of pathologic differentiation of laryngeal and hypopharyngeal squamous cell carcinomaPurpose:To evaluate the discrepancy of parameters generated on dual-energy CT (DECT) imaging in the different pathological grade laryngeal and hypopharyngeal squamous cell carcinoma (LHSCC), and provide help for judging prognosis and guiding clinical treatment.Material and Methods:61 patients with pathologically confirmed LHSCC who underwent contrast enhanced DECT before therapy were retrospectively analyzed. With GSI Volume Viewer software of GE AW4.6 workstation analyzed the enhanced monochromatic data, iodine concentration of lesion (IC-L), water concentration of lesion (WC-L), iodine concentration of carotid sinus (IC-C), water concentration of carotid sinus (WC-C) were acquired, and slope of spectral Hu curve (λHU),standardized IC (sIC), standardized WC (sWC) were calculated. According to cell differentiation, all the patients were divided into well, moderately and poorly differentiated group. The difference of sIC, sWC,λHU T stage and N stage constituent ratio, lymphatic metastasis incidence rate were compared among different groups. Using SPSS 19.0 statistical software, one-way ANOVA, Kruskal-Wallis test and x2 test to do statistical analysis.Results:sIC, λHU of well, moderately and poorly differentiated group were [(30.56± 7.98)×10-2, (24.06±9.21)×10-2, (18.64±5.26) × 1O-2], [(3.01±1.38), (2.50±0.82) and (2.01±0.77)] respectively, and the difference were significant (F=5.75,3.96 respectively, P<0.05); the two-two paired comparisons by least significance difference test (LSD-t) method showed there were significant difference of λHU and between poorly and well-differentiated group (P<0.05), no significant difference were found between poorly and moderately differentiated group (P>0.05); moderately and well differentiated group (P>0.05) respectively; while the difference of sIC were significant in all two-two paired comparisons. The difference of sWC was not significant among the three groups (H=0.01, P>0.05). x2 test showed that there was no significant difference for the constituent ratio of T stage among three groups (P>0.05); there was significant difference for the constituent ratio of N stage and lymphatic metastasis incidence rate among three groups (P<0.05).Conclusion:There was a certain difference for λHU and sIC of different differentiated LHSCC. Poorly differentiated LHSCC more prone to occur lymph node metastasis, and spectral parameters might be helpful in judging prognosis of LHSCC.Part 2:The clinical value of dual-energy CT in diagnosis of lymph nodes metastasis in patients with laryngeal and hypopharyngeal squamous cell carcinomaPurpose:To explore the effect of dual-energy CT (DECT) in diagnosing metastatic lymph nodes on laryngeal and hypopharyngeal squamous cell carcinoma (LHSCC) and establish the thresholds of dual-energy CT (DECT) quantitative parameters and morphology indexes in diagnosis of lymph nodes metastasis of LHSCC.Material and Methods:60 patients with LHSCC confirmed by operation and pathology examination underwent DECT scan with Gemstone Spectral Imaging (GSI) mode before radical resection within 2 weeks were retrospectively studied. According to results of surgery and pathology, a head and neck oncology radiologist with over 10 years experienced chose the representative metastatic and non-metastatic lymph nodes. With GE AW4.6 workstation analyzed the enhanced monochromatic data, short axis(S) and long axis (L) diameter, iodine concentration of lesion (IC-L), water concentration of lesion (WC-L), iodine concentration of carotid sinus (IC-C), water concentration of carotid sinus (WC-C) were acquired in metastatic and non-metastatic lymph nodes, and slope of spectral Hu curve (λHU), standardized IC (sIC), standardized WC (sWC) were calculated. The morphology indexes and dual-energy CT (DECT) quantitative parameters were compared between metastatic and non-metastatic lymph nodes. The parameters with significant difference were analyzed by the logistic regression model, then a new predictive variable (NV) were established. Receiver operator characteristic curve (ROC) analyses were performed in order to identify optimal cut-off value for S, λHU, NV in the diagnosis of lymphatic metastasis. The optimal thresholds were selected as the diagnostic criteria of lymphatic metastasis.Results:Short-axis diameter of metastatic lymph nodes were significantly longer than non-metastatic ones (t=3.86, P<0.05); Long-axis diameter, S/L ratio of metastatic lymph nodes were not significantly longer than non-metastatic ones (t=0.38,1.74, P>0.05).λHU of metastatic lymph nodes were significantly greater than non-metastatic ones t=3.97, (P<0.05); sIC, sWC of metastatic lymph nodes were not significantly greater than non-metastatic ones (Z=-1.45,-1.85, P>0.05). The area under curve (AUC) of S, λHU, NV value diagnosing metastatic lymph nodes of LHSCC were 0.77,0.77,0.87 respectively (P<0.05).The AUC of NV were significantly greater than S or λHU (P<0.05). With threshold value of 0.46 for NV in differentiating metastatic from non-metastatic lymph nodes, the sensitivity and specificity were 90.91% and 74.04% respectively.Conclusion:Diagnostic performance of DECT quantitative parameters were similar to that of morphological parameters. The combination of DECT quantitative parameters and morphological parameters can significantly improve the diagnostic sensitivity and specificity.Part 3:Exploratory study on dual-energy CT quantitative parameters for predicting therapy effects of local advanced laryngeal and hypopharyngeal squamous cell carcinomaPurpose:To evaluate the value of dual-energy CT (DECT) quantitative parameters in predicting therapeutic effects of (chemo-)radiation therapy on local advanced laryngeal and hypopharyngeal squamous cell carcinoma(LHSCC), and provide valuable evidence for early judging the response of the tumor to therapy in clinical practice.Material and Methods:DECT quantitative parameters of 41 patients with primary laryngeal and hypopharyngeal SCC who underwent DECT scan with Gemstone Spectral Imaging (GSI) mode before therapy were analyzed prospectively, all cases were proven by pathological findings. DECT quantitative parameters contained the slope of the spectral HU curve (λHU), standardized iodine concentration (sIC), standardized water concentration (sWC) and effective atomic number (Zeff), which were obtained by analyzing monochromatic data with GSI Volume Viewer software in workstation. The following scans were taken at the 12th week after therapy ended. By therapeutic effects, all patients were divided into complete remission (CR) group and non-complete remission (NCR) group. T stage constituent ratio and spectral parameters between two groups were compared, and the diagnosis experiment was evaluated too.Results:19 of 41 (46.3%) patients showed pathologic complete remission (CR) and 22 (53.7%) showed non-complete remission (NCR). The mean of λHU, sIC, Zeff in the CR group was significantly lower than that in the NCR group (1.96±0.52 VS 2.72±0.64; 0.21±0.05 VS 0.30±0.10; 8.51±0.20 VS 8.71±0.29, P<0.05). There were no significant difference for the constituent ratio of T stage, treatment modality and SWC between two groups (P>0.05). Receiver operating characteristic (ROC) analysis of λHU, sIC, Zeff in prediction of CR effect of local advanced LHSCC showed AUC (the area under curve) was 0.83,0.85,0.70 respectively. Compared the AUC of λHU, sIC, Zeff value, there was no significant difference (P>0.05). With sIC≤0.21, λHU≤2.37, Zeff≤8.55 as optimal diagnosis threshold in prediction of CR, the sensitivity, specificity, positive predictive value(PPV), negative predictive value (NPV) were 84.21%,90.91%,88.9%,87.0%; 84.21%,72.73%,72.7%,84.2%; 68.42%,77.27%,72.2%,73.9% respectively.Conclusion:Quantitative parameters of DECT may be able to identify patients who could successfully respond to therapy, which could potentially help doctor to choose the appropriate treatment regimen for local advanced LHSCC. |
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