Diffusion-weighted Magnetic Resonance Imaging (DW-MRI )for Early Response Assessment in Patients With Esophageal Cancer

Esophageal carcinoma is a lethal disease, causing more than 400,000 deaths annually worldwide. Primary surgery results in microscopically positive resection margins (R1) in 25% patients, and the 5-year overall survival(OS) for such patients rarely exceeds 40%. Concurrent chemoradiation followed by surgery results in better survival than single-modality treatments, and thus National Comprehensive Cancer Network(NCCN) recommends concurrent chemoradiation as preoperative or definitive treatment for patients with stage II or III esophageal cancer. However, neoadjuvant chemoradiation may not be effective in some subgroup of these patients, and its toxicity can increase perioperative mortality and delay or preclude surgery. The ability to distinguish tumors that will respond or not respond to such therapy remains an urgent priority. Diffusion-weighted magnetic resonance imaging(DW-MRI) is based on the extent of mobility of water protons, as quantified by the apparent diffusion coefficient (ADC). The ADC is a measure of the extent of free diffusion of water molecules within tissues, which is mainly influenced by cell organization, size, and density. Cell death leads to a loss of cell membrane integrity and density and leads to increases in ADC values. The ADC has emerged as a potential biomarker of response to cancer therapy. However, no one has published findings regarding the potential correlation between changes in ADC and response of esophageal cancer to chemoradiation. Clarifying the potential predictive value of DW-MRI for predicting response to such therapy is important for the delivery of appropriately tailored treatment.

Investigators hypothesized that DW-MRI can predict the success (or failure) of neoadjuvant chemoradiation in esophageal squamous cell carcinoma（ESCC）, hence identify patients at high risk of treatment failure from such therapy. Investigators will test this hypothesis with two specific aims: (1) assess the ability of ADC to predict pathologic response to treatment; and (2) assess the ability of ADC to predict disease-free survival and overall survival.