Magnetic resonance imaging during definitive chemoradiotherapy can predict tumor recurrence and patient survival in locally advanced cervical cancer: A multi-institutional retrospective analysis of KROG 16-01.

ABSTRACT

OBJECTIVE: Definitive chemoradiotherapy (CRT) followed by brachytherapy is a standard treatment for locally advanced cervical cancer. During CRT, marked reduction of cervical tumor is often observed in magnetic resonance imaging (MRI). The primary aim of this study was to assess the association between tumor response in MRI using FIGO classification and clinical outcomes. METHODS: Multi-institutional data were retrospectively reviewed to identify the significance of MR tumor response on tumor recurrence and patient survival. 225 patients with histologically confirmed squamous cell carcinoma of the cervix, staged as FIGO Ib2-IVa on initial pelvic MRI, were included. Post-CRT MRI was performed median 35days after the beginning of CRT and before brachytherapy. A median 54Gy of external radiation was given with weekly cisplatin during CRT. RESULTS: 112 (49.7%) of the 225 patients showed a positive response in post-CRT MRI and were named the responsive arm. After a median follow-up time of 36.2months, the responsive arm had significantly lower para-aortic recurrence (7.5% vs. 12.4%; p=0.04) and distant metastasis (13.2% vs. 27.6%; p=0.03) rates than did the non-responsive arm. The responsive arm had significantly higher 3-year cause-specific survival rate (94.6% vs. 81.1%, p<0.01) than did the non-responsive arm. In the multivariate analysis, tumor size (hazard ratio, 1.91 and 95% confidence interval, 1.07-3.43; p=0.028) and positive MR response (hazard ratio, 1.75 and 95% confidence interval, 1.06-2.27; p=0.045) were significant factors for recurrence-free survival CONCLUSION: Early tumor response evaluation with MRI using FIGO classification effectively predicted distant tumor metastasis and disease-specific survival in locally advanced cervical cancer.