BackgroundCurrently, the standard treatment for locally advanced cervical cancer patients is concurrent chemoradiotherapy. Here we aim to evaluate therapeutic efficacy, treatment failure, toxicity and prognostic factors for FIGO IIIB cervical cancer patients.MethodsA comprehensive retrospective analysis was performed to understand various factors which contribute to IIIB cervical cancer prognosis. In total 223 well defined patients were assigned according to their pathological subtype, age, pre-treatment HGB level, tumor size, pelvic lymph node (LN) metastasis, para-aortic LN metastasis as well as external irradiation technologies, treatment duration, point A EQD2 dose and concurrent chemotherapy cycles. We then performed correlation studies of these factors and OS, DFS, LCR, DMFS using univariate and multivariate analysis respectively.ResultsWe managed to achieve 207 (92.8%) complete response (CR) and 16 (7.2%) partial response (PR) with acceptable adverse effects. Notably, the 5 years OS, DFS, LCR, DMFS for these patients were 61.1, 55.2, 83.6 and 66.4% respectively. Importantly, our studies suggest that escalated point A EQD2 can significantly improve OS, DFS and LCR for FIGO IIIB cervical cancer patients, furthermore, patients without para-aortic LN metastasis who received prophylactic extended field irradiation have significant survival advantage for DFS and a tendency to improve OS and DMFS.ConclusionsOur results suggest that FIGO IIIB cervical cancer patients should receive higher EQD2 (≥98Gy10) radiotherapy, moreover, patients without para-aortic LN metastasis should receive prophylactic extended field nodal irradiation to improve prognosis.Electronic supplementary materialThe online version of this article (10.1186/s13014-018-1172-1) contains supplementary material, which is available to authorized users.