Quantitative evaluation for preoperative clinical stage of colorectal cancer using dynamic contrast-enhanced magnetic resonance imaging

Abstract

BACKGROUND

The management of patients with colorectal cancer (CRC) mainly lies on the use of magnetic resonance imaging (MRI) technique as a diagnostic tool for both staging and restaging.

AIM

To explore the preoperative value of quantitative parameters of dynamic contrast-enhanced MRI (DCE-MRI) in evaluating clinical stages of CRC.

METHODS

A total of 86 CRC patients undergoing DCE-MRI examinations were included and then classified into CRC group (n = 46) and benign tumor group (n = 40) according to surgical and pathological results. Quantitative parameters of DCE-MRI, including volume transfer constant (Ktrans), rate constant (Kep) and extravascular extracellular volume fraction (Ve), were analyzed between two groups and among CRC at different stages. Receiver operating characteristic (ROC) curves with of quantitative parameters of DCE-MRI for clinical diagnosis and preoperative staging of CRC were plotted.

RESULTS

The CRC group had 9 cases with tumor in the upper segment, 21 cases in the middle segment, 16 in the low segment, 10 cases with well differentiation, 27 cases with moderate differentiation, and 9 cases with poor differentiation. The Ktrans, Kep, and Ve in the CRC group were higher than those in the benign tumor group (P < 0.05). The ROC curves indicated that the optimal cutoff values of Ktrans, Kep and Ve for diagnosing CRC were 0.905 minute^-1, 0.225 minute^-1 and 0.585%, respectively. The Ktrans, Kep and Ve as a combined tool to diagnose CRC yielded 0.863 of area under the curve and 82.60% of sensitivity, and both values were higher than those yielded by Ktrans, Kep, or Ve alone (P < 0.05). The Ktrans, Kep and Ve in CRC patients at T3-T4 stage or N1-N2 stage were higher than those at T1-T2 stage or N0 stage (P < 0.05). Results of Spearman correlation analysis showed that the Ktrans, Kep and Ve were correlated with advanced T and N stages in CRC patients (P < 0.05). The ROC results indicated that the Ktrans produced a higher specificity (81.48%) and sensitivity (94.70%) in evaluating preoperative T stage of CRC. The Kep generated a higher specificity (96.00%) and sensitivity (81.00%) in evaluating preoperative N stage of CRC.

CONCLUSION

The study suggests that the values of Ktrans, Kep and Ve of DCE-MRI exhibit good performance in diagnosing CRC and preoperative assessment of clinical stages. However, relatively small sample size should be considered for data interpretation.

Keywords: Dynamic contrast-enhanced magnetic resonance imaging; Colorectal cancer; Volume transfer constant; Rate constant; Extravascular extracellular volume fraction

Core Tip: Patients with colorectal cancer exhibited higher values of quantitative parameters [volume transfer constant (Ktrans), rate constant (Kep) and extravascular extracellular volume fraction (Ve)] of dynamic contrast-enhanced magnetic resonance imaging than those with benign tumor. Increased values of Ktrans, Kep, and Ve were correlated with more advanced primary tumor and lymph node stages. The values of Ktrans, Kep and Ve exhibited good performance in diagnosing colorectal cancer and preoperative assessment of clinical stages.