Preliminary Study Of ^99mTc-3PRGD₂ SPECT/CT Combined With Enhanced CT In Lymph Node Metastasis Of Lung Malignancies

Ob Jective:To investigate the diagnostic value of ^99mTc-3PRGD₂SPECT/CT imaging combined with enhanced CT for the assessment of lymph node metastasis in lung malignancies,and to analyze the predictive value of imaging parameters of the primary focus and clinical factors on lymph node metastasis.Methods:Forty-one patients with su SPEcted lung malignancies were pro SPEctively collected,and ^99mTc-3PRGD₂SPECT/CT imaging and enhanced CT examination were performed,together with tumor resection and lymph node dissection,and the detection of lymph node metastasis in lung tumors by the above examinations was recorded.The differences in sensitivity,SPEcificity,accuracy,positive predictive value and negative predictive value between^99mTc-3PRGD₂SPECT/CT imaging and enhanced CT for the diagnosis of lymph node metastasis in mediastinal lymph nodes of lung malignant tumors were compared,and the value of gain compensation of enhanced CT for the diagnosis of lymph node metastasis in lung malignant tumors by ^99mTc-3PRGD₂SPECT/CT was analyzed.The comparison of indicators was performed by paired X2 test,and the difference was considered statistically significant when p<0.05.The risk factors for lymph node metastasis of pulmonary malignant tumors in general clinical data and imaging parameters of the primary site were screened by univariate analysis with patients as the basic unit.Results:Among the 41 patients,34 patients with malignant tumors and 7 benign,of which mainly squamous and adenocarcinoma were predominant.Eleven patients with lymph node metastasis in lung malignancy had a total of 27 mediastinal lymph node subdivisions and 45 lymph node metastases.The sensitivity,SPEcificity,accuracy,positive predictive value,and negative predictive value of lymph node metastasis in lung tumors diagnosed by^99mTc-3PRGD₂imaging,enhanced CT,and the combination of both were 54.5%,74.0%,67.6%,50.0%,and 77.3%,72.7%,39.1%,50.0%,36.4%,75.0%and 81.8%,91.3%,88.2%,81.8%,91.3%,re SPEctively.The diagnostic ability of^99mTc-3PRGD₂imaging had high SPEcificity and low sensitivity compared to enhanced CT（p=0.031）.The diagnostic efficacy of both methods combined for the diagnosis of malignant lymph node metastases in the chest was higher than that of enhanced CT（p=0.003）and ^99mTc-3PRGD₂imaging（p=1.000）alone.The concordance of diagnostic and pathological findings using Kappa test comparing^99mTc-3PRGD₂SPECT/CT imaging,enhanced CT and both combined was 0.278（p=0.861）,0.094（p=0.104）,and 0.731（p=0.001）,re SPEctively.Among the general clinical data and imaging parameters of the primary foci,only the differences in Ki67 values and the degree of Ki67 expression were statistically significant（p<0.05）,while gender,age,smoking history,ethnicity,family history of tumor,pathological type,degree of differentiation,lung lobe in which the tumor was located,maximum diameter of the primary foci,proportion of solid components of the primary foci,cystic changes,burr sign,vascular collection sign,inflatable bronchial sign,pleural traction sign,the The differences in tumor T-stage,primary foci to mediastinal blood pool count ratio,primary foci CT scan value,primary foci CT enhancement value,primary foci CT enhancement degree,primary foci enhancement mode,tumor location and primary foci border were not statistically significant（p>0.05）.Conclusion:Chest-enhanced CT combined with ^99mTc-3PRGD₂SPECT/CT imaging has high diagnostic efficacy for the diagnosis of lymph node metastasis in lung tumors and helps patients’surgical decision;high Ki67 expression is a risk factor for lymph node metastasis and has predictive value for lymph node metastasis in lung tumors.Ob Jective:To construct,for the first time,a new column line map based on the lymph nodes own imaging parameters for identifying patients at risk of lymph node metastasis.Methods:Based on enhanced CT and^99mTc-3PRGD₂ SPECT/CT imaging,lymph nodes with clear pathological nature and image location were included in the study with reference to the criteria for mediastinal lymph node partitioning developed by the International Association for the Study of Lung Cancer（IASLC）,and pathological findings were used as the "gold standard".The lymph nodes were randomly divided into training and validation groups in the ratio of 7:3,and the differences in imaging parameters between metastatic and non-metastatic lymph nodes were compared on the basis of the lymph nodes themselves,and the statistically different parameters were included in a multivariate logistic regression equation to filter out the diagnostic parameters with diagnostic value and generate a Joint variable diagnostic model for predicting lymph node metastasis.A column line plot containing significant risk factors was created to predict the probability of lymph node metastasis in lung malignancies.The potential of the column line graph was evaluated based on the column line graph ROC curve,calibration and decision curve.Results:Among 34 patients with malignant lung tumors,174 lymph nodes that met the inclusion criteria were randomly divided into 114 in the training group and 60 in the validation group in a 7:3 ratio.In the training and validation groups,the differences in lymph node long diameter,lymph node short diameter,lymph node long diameter/short diameter,margins,necrosis,lymph node to mediastinal blood pool radioactive count ratio（T/B）,lymph node to liver radioactive count ratio（T/L）,lymph node to muscle radioactive count ratio（T/M）,and lymph node enhancement mode were statistically significant（p < 0.05）,while the differences in lymph node location,fat,calcification,lymph node to primary focus radioactive count ratio,lymph node CT plain value,lymph node enhancement CT value and lymph node enhancement were not statistically significant（p >0.05）.parameters with statistically significant differences were included in the multivariate logistic regression equation,and the results of the multivariate analysis showed that the mode of lymph node enhancement was an independent risk factor for lymph node metastasis,and subsequently the six risk factors for which the covariance test showed no serious covariance（long diameter/short diameter,margin,necrosis,lymph node/mediastinal blood pool（T/B）,lymph node/liver（T/L）,and lymph node/muscle（T/M））and lymph node enhancement patterns were included together and a multifactorial logistic regression model for predicting lymph node metastasis was generated.And based on this,column line plots were created and the predictive efficacy of the models was evaluated using ROC curves,calibration curves and decision analysis curves.The area under the working characteristic curve was 0.878 in the training group and 0.949 in the validation cohort for sub Jects,indicating a better ability to predict lymph node metastasis.Calibration curves showed good agreement between predicted and actual results.the Hosmer-Lemeshow goodness-of-fit test showed no statistically significant difference between predicted and observed values（p=0.923）.Decision curve analysis showed that the column line graphs were clinically useful.Conclusions:Columnar line plot models constructed based on the lymph nodes’ own imaging parameters provide a more effective and noninvasive preoperative method to assess patients’ risk of lymph node metastasis without adding additional scanning time and cost,and provide an easy-to-use tool for determining staging and developing appropriate treatment plans.