BackgroundTo prospectively compare the outcomes and side effects between groups of postoperative cervical cancer patients with multiple pelvic lymph node metastases who were treated with extended field or pelvic intensity-modulated radiotherapy (IMRT) with concurrent cisplatin chemotherapy.MethodsCervical carcinoma patients with International Federation of Gynecology and Obstetrics (FIGO) stage Ib-IIa, who underwent radical hysterectomy and had histologically confirmed multiple (≥2) pelvic lymph node metastases, were enrolled into this study. The patients were randomly assigned to pelvic-IMRT or extended field-IMRT (45 Gy/25 Fx) group. Patients in either group received concurrent cisplatin chemotherapy (40 mg/m2) starting on the first day of irradiation.ResultsUntil December 31th 2017, 129 patients were initially enrolled into this study. During the study, 3 patients were dropped out due to either incompletion of the study or exclusion by the criteria. Consequently, 64 patients completed pelvic-IMRT, and 62 patients completed extended field-IMRT. Median follow-up period was 61.30 months in the extended field-IMRT group and 60.60 months in the pelvic-IMRT group. Five-year actuarial survival probability was 0.759 (95% CI: 0.619–0.854) in the extended field-IMRT group which was not significantly different from that of the pelvic-IMRT group [0.824 (95% CI: 0.690–0.905), P=0.442]. Similarly, the five-year progression-free probability was 0.720 (95% CI: 0.576–0.822) in the extended field-IMRT group, which was not significantly different from that of the pelvic-IMRT group [0.781 (95% CI: 0.637–0.874), P=0.389]. In addition, there was no significant difference between the two groups in hematology and gastrointestinal tract toxicities.ConclusionsPost-operative pelvic-IMRT or extended field-IMRT with concurrent cisplatin chemotherapy had similar outcomes in terms of survival rates and adverse events in cervical carcinoma patients at FIGO stage Ib-IIa with multiple pelvic lymph nodes metastases.