Magnetic-resonance imaging in diagnostics of esophageal cancer (literature review)

Carcinoma of the esophagus continues to be a malignant disease with a poor prognosis; the overall five-year survival rate ranges from 15 to 20%. Esophageal cancer is the eighth most common and the sixth most common cause of death among oncological diseases. The main task of esophageal cancer diagnostics is to assess the extent of the pathological process in order to determine the most optimal type of medical care. Currently, endoscopic ultrasonography (EUS) is considered to be the method of choice in determining the T-stage of the primary tumor. Moreover, several studies have shown the better results in N staging using EUS with TAB. At the same time, MRI of the esophagus is considered to be a technically challenging procedure because of difficulties in visualizing due to the motion artifacts. The motor and flow artifacts arising from the heartbeats and pulsations of the aorta and pulmonary vessels significantly reduce the quality of images. Nevertheless, the emergence in the last decade of some technical innovations can significantly reduce the impact of motion artifacts on image quality. For example, the effect of respiratory movements can be leveled using the proposed r-VIBE (radial VIBE) sequence, in which scanning and data collection occurs on the patient’s free breathing. However, in order to obtain high-quality images of the esophagus,(and make accurate staging of esophageal cancer, respectively) it is necessary to use different sequences; the scanning protocol must include T2-WI in several planes using high resolution sequences, DWI, and T1-WI with dynamic contrast enhancement. Application of new data collection technologies allowed to study esophagus on the expert level and to assess the local extent of the process accurately. Moreover, significant progress has been reached in assessing of N-stage in esophageal cancer with MRI in recent years. Unfortunately, a unified sequence protocol has not been developed yet and that makes it difficult to perform a statistical proper meta-analysis.Creating conditions for esophageal cancer treatment indicates development of response predictors to the neoadjuvant chemoradiotherapy (nCRT), which would reliably determine the tumor response rate and likelihood before starting treatment, as well as creating reliable response criteria in the early periods after nCRT based on objective medical imaging data.Another task is creatin of an artifact-decreasing sequence protocol, which would allow to determine theextent of the lesion accurately. In addition, it is necessary to study the possibilities of MRI in the tumor staging, in comparison with the results obtained with EUS, CT, PET-CT in the form of a prospective study with a large sample of patients.