The possibilities of CT and MRI in design of treatment for colorectal liver metastases: a prospective study

Abstract

INTRODUCTION: Frequent detection of liver metastases in colorectal cancer and a high risk of adverse outcomes determine the algorithm for managing such patients, involving maximum early diagnosis and selection of treatment methods.OBJECTIVE: To demonstrate the possibilities of CT and MRI in determining treatment tactics for colorectal liver metastases. MATERIALS AND METHODS: 90 patients with metastatic colorectal cancer in the liver were examined. All patients underwent contrast-enhanced CT. Multiparametric magnetic resonance imaging was performed in 49 patients (54%). The diagnosis was confirmed morphologically and/or by at least one additional method of examination (ultrasound or PET/CT).RESULTS: When a solitary metastatic lesion in the liver or a limited number of lesions within one segment or lobe was identified, the preferred method was typical or atypical liver resection together with drug therapy (38.9%). In the presence of several small metastatic lesions, each with a diameter not exceeding 3 cm, and located far apart from each other, radiofrequency ablation was an additional method to liver resection (4.4%). For unresectable patients and/or non-resectable solitary lesions smaller than 5 cm without evidence of vascular invasion, the preferred method was stereotactic body radiation therapy (SBRT) (13.3%). Marked reduction in liver functional reserve, small remaining liver volume, as well as bilobar involvement precluded the resection of all lesions. Therefore, in cases of bilobar liver involvement where organ-preserving surgery is not feasible, with the presence of extrahepatic metastases, and when the patient is functionally unresectable, the preferred method was drug therapy (33.4%), transarterial chemoembolization (TACE) as a palliative therapy (10%).DISCUSSION: According to the literature, the most sensitive methods for detecting liver metastases are MRI with diffusionweighted imaging (DWI) and the use of hepatospecific contrast agents in the hepatobiliary phase. CT is a reliable method for preoperative staging, providing high-quality visualization of the liver and covering the entire abdominal and thoracic cavities, allowing for the detection of metastases in regional lymph nodes and distant metastases. The statistical regularity we identified confirms these findings. However, in several studies, it has been noted that the sensitivity of MRI with hepatospecific contrast agents in the hepatobiliary phase is higher than DWI when detecting small lesions (less than 10 mm). According to the results of our study, MRI with DWI was found to be more sensitive for detecting small metastatic lesions.CONCLUSION: Contrast-enhanced CT and multiparametric MRI showed high diagnostic value in the assessment of metastatic colorectal cancer in the liver for planning radical surgical intervention and selecting alternative treatment methods.