All eligible patients will be equally randomized between the 2 following treatment groups (stratified factors: whether para-aortic lymph nodes were image-positive):
Standard treatment group: standard chemoradiation (Pelvic EBRT/Extended-field EBRT + concurrent platinum-containing chemotherapy+brachytherapy ±pembrolizumab).
Experimental group: open/minimally invasive pelvic and para-aortic lymph node dissection followed by chemoradiation±pembrolizumab. (Level of lymph node dissection: At least the inferior mesenteric artery. Chemoradiation ±pembrolizumab will be performed postoperatively within 28 days.)