A Multicenter, Randomized Controlled, Phase II Clinical Study of First-line Chemotherapy and Camrelizumab With or Without Radiotherapy in the Treatment of Oligometastatic Esophageal Cancer

Stereotactic body radiotherapy (SBRT, 8Gy/time, 3 -5 times, if other segmentation schemes are used, recommend BED10 \>60Gy) or conventional fractional radiotherapy (parts that are not suitable for SBRT, the total dose is more than 30Gy); the primary lesion should be treated with conventional fractional radiotherapy with a dose of 4000cGy or more;

4 cycles for combined therapy. Camrelizumab maintenance.

4 cycles for combined therapy.