Quantitative Analysis MR In The Early Diagnosis And Response Of Esophageal Carcinoma Undergoing Radiotherapy

Part OnePreliminary Study of IVIM-DWI and DCE-MRI in Early Diagnosis of Esophageal CancerBackgroundsEsophageal cancer is one of the common malignant tumors in China.Squamous carcinoma is the main type. It is characteristic of high degree of malignancy, rapid development, poor therapeutic effect, and high recurrence rate.Early diagnosis and early treatment have important clinical significance on its prognosis. Endoscopic biopsy combined with pathological examination is the main method of preliminary diagnosis of esophageal cancer, especially early esophageal cancer. It pathological change is occult, and there are significant differences in tumor size and shape. Therefore, the misdiagnosis phenomenon of esophageal cancer guided by gastroscope biopsy is to be considered as the recognized defects. The traditional imaging examination analyzed esophageal pathological changes only from morphology.It was not easy to observe the early pathological changes. How to diagnose the disease accurately is the challenge which the imaging examination needs to face. The characteristics of early malignant esophageal tumor were investigated from the molecular level using functional magnetic resonance quantitative imaging technique, and whether the quantitative functional magnetic resonance IVIM-DWI and DCE-MRI could provide the early information for clinical diagnosis was explored in the study.ObjectiveTo investigate the application value of double exponential model diffusion weighted imaging (IVIM-DWI) and dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) in the diagnosis of early esophageal cancer.Methods30 cases of patients with early esophageal cancer confirmed by pathology were collected. They were performed MRI plain scan, IVIM-DWI and DCE-MRI scan. The normal esophageal tissue, Slow ADC value in tumor focus, FastADC value, f value, Ktrans, Kep and Ve values were measured. The difference between cancer tissue and normal tissue was compared using two independent sample t test. The prediction parameters and diagnostic threshold were compared by drawing receiver operating characteristic curve (ROC).ResultsThe average f, Ktrans and Kep values in esophageal cancer and normal esophageal tissue were:(0.48±0.19), (0.64±0.08), (0.45±0.19)/min, (0.14±0.04)/min and (1.14±0.42)/min, (0.56±0.25)/min respectively. Compared with normal esophageal tissue, esophageal cancer f value decreased, Ktrans value increased, Kep value increased, and the difference was statistically significant (P<0.05);There was no difference in SlowADC, FastADC, Ve values of esophageal cancer and those in normal esophageal tissues (P>0.05). The areas under ROC curve F, Ktrans and Kep values were 0.90,0.98 and 0.92 respectively. They had the higher diagnostic efficiency.ConclusionIVIM-DWI and DCE-MRI can be used as the imaging method to diagnose esophageal malignant tumor, which has the higher diagnostic value.Part TwoQuantitative analysis dynamic contrast enhanced MR in the early response of esophageal carcinoma undergoing radiotherapyBackgroundThe quantity of tumors’ new vessels and the permeability of vessel wall can reflect the activity of tumor tissues. Radiotherapy can inhibit the expression of VEGF effectively, thus preventing the regeneration of tumors’new vessels. DCE-MRI takes advantage of dynamic enhancement and pharmacokinetic theory, and measures the value of Ktrans, Kep, and Vein the region of interest(ROI) to monitor the condition in which the contrast agent penetrates the vessel wall and the distribution of contrast agent in EES (extravascular extracellular space). DCE-MRI double ventricle model technique was used to analyze the variation of quantitative parameters in patients with II-III stage esophageal carcinoma before radiotherapy and after 3 weeks treatment, in order to investigate whether quantitative dynamic contrast enhanced MR can predict early response in primary esophageal carcinoma undergoing radiotherapy.ObjectiveTo investigate application value of quantitative analysis dynamic contrast enhanced MR in early response of esophageal carcinoma undergoing radiotherapy.Methods39 patients who were pathologically proved the II-III stage esophageal carcinoma underwent DCE-MRI before and after 3 weeks radiotherapy, the quantitative parameters(Ktrans, Kep, and Ve)were analyzed respectively. After 1 month of 4-6 weeks treatment,using RECIST1.1 standard criteria all cases were categorized as complete response (CR), partial response (PR), stable disease (SD),disease progression (PD). Independent samples mann-whitaey T test was used to compare the quantitative parameters between effective group (CR+PR) and invalid group (SD+PD) before radiotherapy.Statistical analysis was performed using Wilcoxon’s signed rank test comparison of the two groups before and after 3 weeks radiotherapy parameter values.All tumor volume were analyzed by paired-sample T test to compare before and after 3 weeks radiotherapy.Results30 patients were grouped into effective group and 9 patients invalid group. There were a significant difference between the two groups for Ktransbut there were no significant difference between the two groups for Kep and Ve.after 3 weeks treatment the value of Ktrans and Kep decreases in effective group.there were no significant difference between the two groups values.There were no significant difference in size before and after 3 weeks radiotherapy.ConclusionAfter 3 weeks radiotherapy,the evaluation system that volume changes is limited in the earlier stages.but quantitative dynamic contrast enhanced MRI can predict response in primary esophageal carcinoma undergoing radiotherapy.