Changes in magnetic resonance imaging T2-weighted imaging signal intensity correlated with concurrent chemoradiotherapy response in cervical cancer

Purpose
This study is aimed to compare magnetic resonance imaging (MRI) parameters and clinical pathological factors (CPF) of residual tumor group with non-residual tumor group in cervical cancer (CC) patients during concurrent chemoradiotherapy (CCRT), and thus to establish a biomarker for individualized treatment strategy.

Material and methods
From May 2014 to November 2015, 164 CC patients were included in this retrospective study. T2-weighted MRI was performed at pre-treatment (week-0), the completion of external radiotherapy (RT) (week-4), and one month after the completion of CCRT, using 3.0T MR scanner with regular pelvic coil. Mean signal intensity and tumor size on T2WI images were measured and calculated for each tumor, and lumbar 4-5 intervertebral disc at week-0 and week-4. All patients subsequently underwent routine follow-up, including periodic clinical and imaging examinations when necessary. Receiver operator characteristics (ROC) analysis were conducted to determine cut-off values.

Results
The residual tumor group showed a higher Δ tumor-to-disc signal intensity ratio (ΔTDR) than non-residual tumor group (0.78 ± 0.30 vs. 0.48 ± 0.19, t = 3.42, p < 0.05). The biomarker of combined MRI parameter and CPF showed the highest diagnostic performance than single MRI parameter or CPF alone.

Conclusions
MRI parameter ΔTDR may be an independent prognostic factor for predicting residual tumor occurrence in CC after CCRT treatment. The combination of MRI parameter and CPF can serve as a valuable biomarker to distinguish CC with higher possibility of residual tumor occurrence.