Pelvic RT Versus Prophylactic Extended-field RT in Patients With Cervical Cancer

Inclusion Criteria: 1. Patients must be informed of the investigational nature of this study and give written informed consent with 30 days before treatment. 2. Age ≥18 years and ≤ 70 years. 3. Patients with newly histologically confirmed cervical cancer, including squamous cell carcinoma, adenocarcinoma and adenosquamous carcinoma, et al. 4. No evidence of para-aortic metastatic lymph nodes (MLNs) on CT, MRI or positron emission tomograph (PET)/CT.\* 5. No evidence of distant metastasis (FIGO stage IVB). 6. At least meet one of the following characteristics: 1. Number of pelvic MLNs ≥ 2; 2. Short diameter of pelvic MLNs ≥ 1.5cm; \* 3. Parametrial involvement to the pelvic wall ＃. 7. Satisfactory performance: Eastern Cooperative Oncology Group (ECOG) score ≥ 2. 8. Adequate marrow: neutrophile granulocyte count ≥1.5\*10\^9/L, hemoglobin ≥ 80 g/L, platelet count ≥100\*10\^9/L. 9. Normal liver and kidney function: Creatinine (Cr) \< 1.5 mg/dl, Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST) \< 2\*upper limit of normal (ULN). * MLNs refer to positive lymph nodes confirmed by PET/CT or lymph nodes with short diameter ≥ 1 cm on CT or MRI. * Parametrial involvement to the pelvic wall is diagnosed with gynecological examination or MRI; Exclusion Criteria: 1. With common iliac MLNs. 2. Tumor extended to the lower third of the vagina. 3. Tumor spread to mucosa of the bladder or rectum. 4. Prior surgery (including pelvic or para-aortic lymph nodes resection, except for tumor biopsy), radiotherapy or chemotherapy to primary tumor or nodes. 5. Prior malignancy. 6. History of previous radiotherapy to the abdomen or pelvis. 7. Pregnancy or lactation. 8. Active inflammatory bowel disease, or history of severe stomach or duodenal ulcer. 9. Active infection with fever. 10. Patients with unacceptable risk that intracavitary brachytherapy can not be conducted. 11. Any severe disease which may bring unacceptable risk or affect the compliance of the trial, for example, unstable cardiac disease requiring treatment, renal disease, chronic hepatitis, diabetes with poor control, and emotional disturbance.