Advances in preoperative imaging evaluation of extramural vascular invasion of rectal cancer / 中国医师杂志

Rectal cancer is a common malignancy of the gastrointestinal tract. Extramural vascular invasion (EMVI) is a key indicator of risk stratification for rectal cancer and an important reference factor in determining individualised treatment options, so it is important to accurately assess whether extramural vessels are infiltrated by the tumour before surgery. The main imaging methods for rectal cancer include magnetic resonance imaging (MRI), computed tomography (CT) and transrectal ultrasound (TRUS). This article focuses on the performance and diagnostic efficacy of these imaging methods in the diagnosis of EMVI in rectal cancer, and provides clinical reference.

Significance of paying attention to extramural vascular invasion before operation for rectal cancer / 国际外科学杂志

Rectal cancer is one of the most common malignant tumors of digestive system. Accurate preoperative diagnosis plays an important role in surgeons′ decision on treatment plan. Extramural venous invasion (EMVI), as an important prognostic factor for predicting lymph node metastasis, distant metastasis and overall survival time of rectal cancer, has been paid more attention in recent years. It may even be used as a new staging system for guiding clinical treatment and formulate accurate preoperative staging. Preoperative MRI(mrEMVI) and postoperative pathology (pEMVI) is equal in the accuracy of assessment of EMVI. mrEMVI can be used as an important item for preoperative multi disciplinary team or clinicians to evaluate the patient stage and formulate individual treatment plan, and can also be used as an important evaluation for whether to perform surgery after preoperative chemoradiotherapy (CRT) and whether to prolong postoperative chemoradiotherapy time. EMVI should be taken as one of the necessary preoperative examinations for all the rectal cancer patients.

Clinical value of extramural vascular invasion in rectal cancer / 中华放射肿瘤学杂志

Extramural vascular invasion (EMVI) is a prognostic factor in rectal cancer. The previous evaluation of EMVI relies on the analysis of postoperative pathological results. With the development of MRI, MRI can accurately assess the status of EMVI (mrEMVI). MrEMVI has become the important prognostic indicator for rectal cancer. The risk of local recurrence and distant metastasis in mrEMVI-positive patients will be significantly increased. The aim of this article is to review the diagnostic features, clinical significance, and impact on treatment patterns of EMVI, and project its future development trend of EMVI.

Value and related factors of preoperative diagnosis of extramural vascular invasion of rectal cancer by 3.0T magnetic resonance imaging / 中华肿瘤杂志

Objective@#To evaluate the value of preoperative diagnosis of extramural vascular invasion (EMVI) of rectal cancer with 3.0T high-resolution magnetic resonance imaging (MRI) and the MRI-related factors of EMVI in rectal cancer.@*Methods@#The clinical and imaging data of 40 patients with rectal cancer were retrospectively analyzed. The postoperative pathological diagnosis was used as the gold standard to evaluate the diagnostic efficacy of preoperative diagnosis of EMVI of rectal cancer by high-resolution MRI, and to analyze the relationship between the EMVI and clinical and MRI features.@*Results@#Of the 40 patients, 19 cases were diagnosed as positive EMVI and 21 were negative by MRI. Pathological diagnosis of EMVI was positive in 10 cases and negative in 30 cases. The sensitivity, specificity and accuracy of MRI in the diagnosis of EMVI were 100%, 70.0% and 77.5%, respectively. Preoperative MRI and postoperative pathology were moderately consistent in the diagnosis of EMVI in rectal cancer (Kappa=0.538, P<0.001). Pathological EMVI positivity were related to tumor size under MRI examination (P=0.028), degree of differentiation (P<0.001), depth of invasion (P=0.002), lymph node metastasis (P=0.001), liver metastasis (P=0.011), tumor apparent diffusion coefficient (ADC) value (P=0.010) and exponential apparent diffusion coefficient (eADC) value (P=0.003). It also related to extramural nerve invasion by pathological examination (P=0.005).@*Conclusion@#According to the EMVI imaging score of rectal cancer, preoperative MRI has a high value in the diagnosis of EMVI of rectal cancer.

Faster R-CNN-based artificial intelligence image-aided diagnosis platform in identifying EMVI of rectal cancer: A multicenter clinical study / 中国实用外科杂志

OBJECTIVE: To explore the clinical application value of artificial intelligence image aided diagnosis platformbased on Faster R-CNN in identifying EMVI of rectal cancer.METHODS: In the multicenter retrospective study,500 patients with rectal cancer who underwent high-resolution MRI examination between July 2016 and February 2019 wereselected from seven hospitals in China. They were divided into 174 positive and 326 negative patients. Patients wererandomized to a training group(400 patients,including 133 positive and 267 negative) and a validation group(100 patients,including 41 positive and 59 negative) using a random number method. Using the Faster R-CNN to learn and train 20 430 high-resolution MRI images of thetraining group,an artificial intelligence image-aided diagnosis platform was established. The5107 high-resolution MRI images of thevalidation group were clinically validated.Receiver operating characteristic(ROC) curveand area under the curve(AUC) were used tocompare the diagnostic results of the artificialintelligence image-aided diagnosis platform andthe senior image expert.RESULTS: The accuracy,sensitivity,specificity,positive predictive valueand negative predictive value of EMVI forartificial intelligence image-aided diagnosis platform were 93.4%, 97.3%, 89.5%, 0.90 and 0.97,respectively. The area under the receiver operating characteristiccurve(AUC) was 0.98. The time required to automatically recognize a single image was 0.2 seconds,which had clearadvantages compared to radiologists(estimated to be about 10 seconds).CONCLUSION: The artificial intelligence image-assisted diagnosis platform based on Faster R-CNN has high efficiency and feasibility for identifying rectal cancerEMVI,and can assist imaging diagnosis.

Advances in imaging and pathological research on extramural vascular invasion of rectal cancer / 中华消化外科杂志

Extramural vascular invasion(EMVI)was defined as the presence of tumor cells within an endotheliumlined vessel beyond the muscularis propria.High-resolution MRI had 100％sensitivity and 89％specificity in identification of large(caliber greater than 3 mm)EMVI with histopathology as reference.EMVI detected by both histopathology and MRI was significantly associated with local recurrence,distance metastasis and tumor-related death in rectal cancer,which was also identified as an independent prognostic factor for 3-year tumor-free survival and overall survival.EMVI could be used as one of the risk factors,which would allow stratification of patients with rectal cancer to receive neoadjuvant chemoradiotherapy(neoCRT).Moreover,EMVI detected by high-resolution MRI was identified as an independent predictor for response to neoCRT.Tumor regression grading scale defined by high-resolution MRI could be used to evaluate EMVI regression after neoCRT.

Value of the high-resolution magnetic resonance imaging in diagnosis of extramural vascular invasion of rectal cancer / 实用放射学杂志

Objective To investigate the value of high-resolution magnetic resonance imaging (HRMRI)in diagnosis of extramural vascular invasion (EMVI)of rectal cancer.Methods 33 patients with rectal cancer were reviewed preoperatively.The MRI findings of EMVI of all cases were scored and compared with the postoperative pathological results.Results The MRI EMVI scores were consistent with histopathology findings (k=0.324,P=0.039).The accuracy rate of MRI in diagnosis of EMVI was 66.7% (22/33).The MRI EMVI scores rose up with increased pT stage,meanwhile there was a high correlation between both (r=0.546).The percentage of MRI EMVI positive number was increased with elevated pT stage,and there was also a high correlation between both (r=0.469). ROC curve showed that MRI EMVI scoring was an effective method in diagnosis of rectal cancer EMVI (AUC=0.757).Conclusion HRMRI is a valuable method in diagnosis of EMVI of rectal cancer.