Patients with primary, untreated, histologically confirmed carcinoma of the uterine cervix are included in this study. Absence of metastatic para-aortic lymphadenopathy is the prerequisite of the enrollment, and this is confirmed by imaging studies such as MRI covering the abdomen and pelvis, and PET/CT scan. The sample size is based on the previous studies (1-3). Considering that the disease-free survival of the experimental arm (patients who are treated with prophylactic para-aortic LN irradiation) and those who are not treated is 82% vs 72% (preliminary analysis), with the alpha error of 5% and statistical power of 90% (one-sided), a total of 140 patients in each treatment arm is needed. With 10% of follow-up loss taken into account, the total number of patients will be 312. Above figures were calculated on the basis of 80% statistical power and 5% type I error rate. PAN is treated prophylactically in the experimental arm with 45Gy/25F/5week fractionation schedule. Pelvis is treated according to the individual institute's practice guideline. Boost treatment for any enlarged pelvic lymph node or residual cervical/ parametrial disease with conformal radiation technique are allowed. Intracavitary radiation is given via low-dose-rate or high-dose-rate brachytherapy technique. Weekly cisplatin is given to all patients, however, when the patient's physical condition does not allow cisplatin administration, it can be omitted. This should be taken into account in the final analysis. The stage and the presence of pelvic lymphadenopathy are two stratification factors.