The Value Of Endoscopic Ultrasonography Combined With Contrast-enhanced Technique In The Malignant Potential Assessment Of Gastrointestinal Stromal Tumors

Objective:Gastrointestinal stromal tumors(GIST)are the most common mesenchymal tumors of gastrointestinal tract,accounting for 1% ~ 2% of gastrointestinal tumors.The biological behavior of GIST is diverse,and about10% ~ 30% of gastrointestinal stromal tumors are malignant tumors [1].SEER data shows that even small GIST may also be malignant.At present,recurrence risk is graded according to postoperative histology,and preoperative benign and malignant GIST cannot be predicted.How to evaluate the malignant potential of GIST before surgery,especially in the early stage of its development,is a key problem to be solved urgently.In this study,endoscopic ultrasonography combined with contrast-enhanced technique was used to evaluate the diagnostic value of malignant potential in GIST.Methods:Patients diagnosed with gastric submucosal tumor by endoscopy were selected from the outpatient department of the Fourth Hospital of Hebei Medical University from October 2016 to October2020.They were evaluated preoperatively by endoscopic ultrasonography combined with contrast-enhanced techniques.Forty-two patients with GIST were confirmed by surgery or endoscopic ESD surgery,and the pathological results of the final surgical specimen were used as the gold standard.Two groups were divided according to the risk assessment system for postoperative recurrence of primary resectable GIST(NIH2008 modified),Ⅰ group(low malignant potential)contains very low,low risk of recurrence;Ⅱ group(high malignant potential)containing moderate,high risk of recurrence in patients.We evaluated the evaluation indexes of preoperative ultrasound and contrast-enhanced techniques to explore their value in predicting the biological behavior of GIST.Results:There were 27 patients in Group Ⅰ and 15 patients in GroupⅡ.There were no statistically significant differences in age,sex,or tumor site between the two groups.In the parameters monitored by EUS,there was no statistical difference in the growth pattern and elastography characteristics between the two groups(P > 0.05).The maximum diameter of the tumor measured by endoscopic ultrasonography could accurately reflect the actual size,but was slightly smaller than the actual size(The difference between EUS measurement size and actual specimen size was-2.73±5.51 mm,P>0.05).Tumor diameter in Group Ⅰ biggest significantly less than Group Ⅱ(25.09±2.37 mm vs 46.53±5.14mm).The data comparison between the two groups was statistically significant(P < 0.05).The detection rates of anechoic areas appeard within the tumor,unclear boundary of the tumors,doppler blood flow signal of Goup Ⅱ are obviously higher than that of GroupⅠ.The data comparison between the two groups was significant(P < 0.05).The detection rates of the enhanced imaging technology’s enhanced strength and uneven degree of GoupⅡ are also higher than that of GroupⅠ.The comparison was statistically significant(P < 0.05).Conclusions:1.EUS can accurately measure the size of GIST in the stomach,and the tumor size is a key factor in evaluating the malignant potential of GIST.2.The tumor boundary,echo homogeneity and Doppler blood flow signal in EUS monitoring parameters are related to the malignant potential of GIST.3.Endoscopic ultrasonography combined with contrast-enhanced technology can more accurately predict the malignant potential of GIST.