ABSTRACT
Objective:To investigate whether radiomics based on ultrasound images can predict lym-phatic metastasis of rectal cancer before surgery.Methods:A total of 80 patients with rectal cancer who underwent endorectal ultrasound (TRUS) and endorectal elastography were confirmed by postoperative pathology in Zhejiang Cancer Hospital from January 2016 to December 2019 were retrospectively analyzed. The general characteristics (gender, age, tumor size, depth of tumor infiltration, tumor location, carcinoembryonic antigen, glycoantigen 199) of the lymph node metastasis group ( n=27) and the non-metastasis group ( n=53) were compared, and the clinical risk factors with statistically significant differences were screened out. The tumor maximum sagittal 2D TRUS images and endorectal elastography were manually outlined, and the radiomics features were extracted using the open source software pyradiomics 3.0.1, and the filtering and embedding methods were used to reduce the dimensionality of the data to select the important features and obtain the best parameters of the model. Then all samples were randomly divided into training and validation sets in the ratio of 8∶2, the models were trained using the best model parameters, which were tested and validated in the validation set, and the predictive efficacy of different models was evaluated according to the ROC curve. Results:The depth of tumor infiltration was statistically significant in predicting whether the lymph nodes metastasized or not (χ 2=11.555, P<0.05), and its area under ROC curve(AUC) value was 0.699. A total of 1 710 features were extracted from sagittal 2D TRUS images and endorectal elastography. After pre-processing and screening, 10 features were strongly correlated with lymph node metastasis status. The 10 features were used to construct the prediction models with AUC values of 0.703, 0.726 and 0.742 for the Logistic Regression Model, Random Forest Model and Support Vector Machine Model, respectively. And the AUC value of the ensemble averaging model in the validation set was 0.734. The imaging-omics prediction model outperformed the prediction model based on statistical analysis of clinical data (AUC: 0.734 vs 0.699, Z=1.984), with a statistically significant difference ( P<0.05). Conclusions:The endorectal ultrasound and endorectal elastography-based radiomics model constructed in this study is better than the model constructed based on statistical analysis of clinical data only, and it is valuable for preoperative lymph node metastasis prediction in rectal cancer.
ABSTRACT
Objective:To investigate the value of ultrasound combined with thyroglobulin (Tg) in preoperative N staging of thyroid carcinoma.Methods:The clinical data of 1 138 patients with thyroid carcinoma in the Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital) from August 2018 to October 2020, who confirmed by surgery and pathology were analyzed retrospectively. The 1 138 cases were divided into pN0, pN1a, and pN1b stages. Kappa consistency test was used to analyze the consistency of ultrasound evaluation of N staging and pathological N staging. Pathology result was taken as the gold standard to analyze the correlation between some preoperative serum markers and lymph node metastasis. The ROC curve was used to compare the diagnostic value of ultrasound, Tg, and ultrasound combined with Tg for lymph node metastasis.Results:The preoperative ultrasound assessment of N staging was moderately consistent with pathology(Kappa=0.459, P<0.01). Between pN0 and pN1(pN1a+ pN1b) stages, the differences in free triiodothyronine (fT3), anti-thyroid peroxidase antibody (TPOAb) and Tg were statistically significant (all P<0.05). Among the different indicators, only Tg had significant effect on lymph node metastasis ( P<0.01) .The area under the ROC curve (AUC) of Tg in predicting lymph node metastasis of thyroid cancer was 0.679, while the best cut-off value for Tg was 25.245 μg/L. The AUC of only ultrasound and ultrasound combined with Tg were 0.699 and 0.775, respectively. Therefore, combined diagnosis method was better than ultrasound only. Conclusions:Preoperative ultrasound and thyroglobulin has a specific value in evaluating the N staging of thyroid carcinoma. The combination of the two is more valuable in the diagnosis of lymph node metastasis than ultrasound only.