Dynamic Changes of CtDNA to Evaluate the Efficacy of Immunoconsolidation Therapy After Radiotherapy and Chemotherapy for Esophageal Cancer

"dynamically monitor the changes of ctDNA in patients with esophageal cancer Radiation: Radiotherapy 95% PTV50-50.4Gy/25-28fractions, 1.8-2Gy/1 fractions; 5 days a week; 6 weeks. Chemotherapy:weekly paclitaxel (50mg/m²) in combination with carboplatin (AUC=2) chemotherapy, a total of 4-5 cycles.~Other Names:~Intensity-modulated radiotherapy (IMRT) Drug: Toripalimab Toripalimab (240 mg, intravenously infused) will be administered as the maintenance treatment every 3 weeks within 4 weeks after the completion of radiotherapy for 1 years or until progression, intolerable toxicity, or physician/patient decision~Other Names:~Immunotherapy ctDNA detection: The first tissue and blood ctDNA test (T0) before treatment is based on next generation sequencing (NGS) technology, and ctDNA test is based on tumor- prior analysis informed assays method. Blood ctDNA testing after chemoradiotherapy was performed every 3 months"