Unresected small lymph node assessment predicts prognosis for patients with pT3N0M0 thoracic esophageal squamous cell carcinoma

Background The role of unresected small lymph nodes (LNs) which may contain metastases for thoracic esophageal squamous cell carcinoma (TESCC) has not been addressed. The aim of the study was to investigate the role of unresected small LNs assessment using computed tomography (CT) in prognostic estimates of pT3N0M0 TESCC patients. Methods Between January 2009 and December 2017, 294 patients who underwent esophagectomy with R0 resection at Sichuan Cancer Hospital were retrospectively examined, and the last follow-up time was July 2018. Patients were classified into CT-suspect and CT-negative groups according to the shortest diameter and the shape (axial ratio) of the unresected small LNs on preoperative CT. The Kaplan–Meier method was used to compare survival differences in prognostic factors. Univariate and multivariate analyses were performed to identify prognostic factors for survival and recurrence. Results Eighty-four patients (28.6%) were classified as CT-suspect group according to the diagnostic criteria; survival analysis suggested that CT-suspect group of patients had a relatively poorer prognosis (P<0.05). Cox regression analysis indicated that unresected small LNs status, tumor grade, and postoperative adjuvant therapy were independent prognostic factors for patients with pT3N0M0 TESCC (P<0.05). Further analysis shown the rates of total recurrence (TR) and locoregional recurrence (LR) in the CT-suspect group were significantly higher than that in the CT-negative group (TR, P<0.001; LR, P<0.001). Among the LRs, the rate of supraclavicular lymph node recurrence in the CT-suspect group was significantly higher than that in the CT-negative group (P<0.001). Conclusions Unresected small lymph node assessment is critically important and predict prognosis for pT3N0M0 TESCC patients.

Dual-Source Dual-Energy Thin-Section CT Combined with Small Field of View Technique for Diagnosing Small Lymph Node in Thyroid Cancer

The authors have requested that this preprint be withdrawn due to erroneous posting.

Dual-Source Dual-Energy Thin-Section CT Combined with Small Field of View Technique for Diagnosing Small Lymph Node in Thyroid Cancer

Background To evaluate the diagnostic performance of quantitative special CT parameters derived from dual-source dual-energy CT at small field of view (FOV) for small lymph node metastasis in thyroid cancer. Methods This was a retrospective study. From 2016 to 2019, 280 patients with thyroid disease underwent thin-section dual-source dual-energy thyroid CT and thyroid surgery. The data of patients with lymph nodes having a short diameter of 2-6 mm were analyzed. The targeted lymph nodes were sketched, their quantitative dual-energy CT parameters were measured, and all parameters between metastatic and nonmetastatic lymph nodes were compared. These parameters were then fitted to univariable and multivariable binary logistic regression models. The diagnostic role of spectral parameters was analyzed by receiver operating characteristic curves and compared with the McNemar test. Small FOV CT images and a mathematical model were used to judge the lymph nodes status respectively and then compared with pathological results.Results Of the 216 lymph nodes investigated in this study, 52.3% and 23.6% had a short diameter of 2-3 mm and 4 mm, respectively. Multiple quantitative CT parameters were found to be significantly different between benign and malignant lymph nodes and binary regression analysis was performed. The mathematical model was: p=ey/(1+ ey), y= = -23.119+0.033×precontrast electron cloud density+0.076×arterial phase normalized iodine concentration+2.156×arterial phase normalized effective atomic number -0.540×venous phase slope of the spectral Hounsfield unit curve +1.676×venous phase iodine concentration. This parameter model has an AUC of 92%, with good discrimination and consistency, and the diagnostic accuracy was 90.3%. The diagnostic accuracy of CT image model was 43.1%, and for lymph nodes with short-diameter 2-3 mm, the diagnostic accuracy was 22.1%.Conclusions Parameter model show higher diagnostic accuracy than CT image model for diagnosing small lymph node metastasis in thyroid cancer, and quantitative dual-energy CT parameters were very useful for small lymph nodes that were difficult to be diagnosed only on conventional CT images.Trial registration This study is retrospectively registered, and we have registered a prospective study (Registration number: ChiCTR2000035195;http://www.chictr.org.cn)