INFORMATIVE VALUE OF RADIATION DIAGNOSIS METHODS IN ESOPHAGEAL-GASTRIC JUNCTION CANCER
The use of various modern radiological diagnosing methods of cancer in the esophago-gastric junction (EGJ) at a preoperative stage is analyzed on the basis of literature data in order to identify the most informative method among them both in terms of opportunities for primary tumor detection and determining the extent of the tumor process. Currently stomach cancer remains an urgent problem. The incidence of stomach cancer in Russia for many years has remained quite high. In 2017 gastric cancer ranked 6<sup>th</sup> (25,4 per 100 thousand persons) among all malignant neoplasms in population of Russia. In mortality structure cancer of a stomach ranked higher, the 2<sup>nd</sup> place (9,8 per 100 thousand persons). The rates of untimely diagnosis of gastric cancer and, accordingly, mortality during one year after making the diagnosis, are extremely high amounting to 46,6%. Despite some decrease in the incidence of cancer in distal gastric segments, in recent years there has been an increase in the frequency of tumor lesions in the EGJ. Localization of the tumor in the proximal stomach part causes a more unfavorable prognosis for patients due to later clinical manifestations and characteristics of metastases. The analysis of available publications of domestic and foreign authors showed that the problem of timely detecting EGJ cancer remains relevant in view of complexity of examining the proximal stomach segments. The problem of differential diagnosis of reactive and metastatic lesions in regional lymph nodes remains unsolved. A comparative study of opportunities in using various methods of radiation diagnosis, ranging from radiography and ending with modern techniques such as magnetic resonance imaging, computed tomography, ultrasound examination of the stomach showed the need for targeted use of these methods, taking into account sensitivity and specificity of each of them, depending on specific location of the tumor in the stomach and extent of the tumor process. Thus, it is necessary to introduce more widely into clinical practice MRI and ultrasound examination of the stomach due to their high soft tissue resolution.