Introduction To assess the tumor response following definitive concurrent chemoradiotherapy (CCRT) for locally advanced cervical cancer (LACC) using magnetic resonance imaging before and after treatment. The prognosis and side effects of CCRT with weekly cisplatin plus paclitaxel versus tri-weekly cisplatin plus paclitaxel should also be compared.

Methods We collected clinical data from the medical records of patients diagnosed with International Federation of Gynecology and Obstetrics (FIGO 2018) stage IIB to IIIC1r LACC at Chongqing University Cancer Hospital from 1 March 2016 to 31 November 2020. A total of 191 patients who underwent MRI before CCRT and 1,3,6 months after CCRT were included in this analysis.

Results With a median follow-up of 39 months, the complete response rates were 57.8% vs. 41.2% (P=0.026) in the weekly and triweekly groups at 1 month, 72.2% vs. 60.7% (P =0.086) and 76.6% vs. 71.3% (P=0.400) at 3 and 6 months. Separately, the 5-year OS was 83.1% vs. 82.7% (P=0.690) and the PFS was 80.4% vs. 83.5% (P=0.650). Patients with residual disease>1 cm and ≤1 cm had a median PFS rate of 88.3% and 57.4%, respectively (P=0.000). An increase in toxicities were observed in the tri-weekly group in terms of grade 3/4 thrombocytopenia (P=0.000) and grade 1/2 nausea/vomiting (p=0.049).

Conclusion/Implications Tri-weekly cisplatin & paclitaxel chemotherapy concurrent with radiotherapy showed worse short-term efficacy compared with the weekly group, and increased side effects but didn’t improve PFS and OS. Patients with residual disease measuring more than 1 cm associated with worse PFS.