Shear-wave elastography predicts T-restaging and pathologic complete response of rectal cancer post neoadjuvant chemoradiotherapy.

PURPOSE: To investigate the value of shear-wave elastography (SWE) in assessing the response to neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer. METHODS: In this study, 455 participants with locally advanced rectal cancer who underwent nCRT at our hospital between September 2021 and December 2022 were prospectively enrolled. The participants were randomly divided into training and test cohorts in a 3:2 ratio. Clinical baseline data, endorectal ultrasound examination data, and SWE measurements were collected for all participants. Logistic regression models were used to predict whether rectal cancer after nCRT had a low T staging (ypT 0-2 stage, Model A) and pathological complete response (pCR) (Model B). Paired Chi-square tests were used to compare the diagnostic performances of the radiologists to those of Models A and B. RESULTS: In total, 256 participants were included. The area under the receiver operating characteristic curve of Models A and B in the test cohort were 0.94 (0.87, 1.00) and 0.88 (0.80, 0.97), respectively. The optimal diagnostic thresholds for Models A and B were 14.9 kPa for peritumoral mesangial Emean and 15.2 kPa for tumor Emean, respectively. The diagnostic performance of the radiologists was significantly lower than that of Models A and B, respectively (p < 0.05). CONCLUSION: SWE can be used as a feasible method to evaluate the treatment response of nCRT for locally advanced rectal cancer.

A prospective study on using shear wave elastography to predict the ypT0 stage of rectal cancer after neoadjuvant therapy: a new support for the watch-and-wait approach?

Introduction: The diagnostic accuracy of traditional imaging examination in predicting ypT stage of rectal cancer after neoadjuvant therapy is significantly reduced, which would affect patients' subsequent treatment choices. This study aimed to investigate the use of endorectal shear wave elastography (SWE) for diagnosing ypT0 stage of rectal cancer after neoadjuvant chemoradiotherapy (nCRT). Methods: Sixty patients with rectal cancer were prospectively recruited in this study. Data on endorectal ultrasound (ERUS) and SWE parameters were collected before nCRT and 6-8 weeks after nCRT. Postoperative pathological results were the gold standard for evaluating the diagnostic accuracy of SWE and ERUS in predicting the ypT0 stage of rectal cancer after nCRT. Receiver operating characteristic (ROC) curve analysis was used to determine the cut-off values of the SWE parameters that best corresponded to the ypT0 stage and analyze the sensitivity, specificity, and accuracy. Results: The diagnostic accuracies of using ERUS to predict the ypT and ypT0 stages of rectal cancer after nCRT were 58.1% (18/31) and 64.3% (9/14), respectively. The ROC curve was constructed with the lesion's Emean, Emean corrected (EC), Emean difference (ED), Emean corrected differencede (ECD), Emean descendding rate (EDR) and Emean corrected descendding rate (ECDR) values after nCRT, the cut-off values of diagnosing the ypT0 stage were 64.40 kPa, 55.45 kPa, 72.55 kPa, 73.75 kPa, 50.15%, and 55.93%, respectively; the area under the curve (AUC) for diagnosing the ypT0 stage was 0.924, 0.933, 0.748, 0.729, 0.857 and 0.861, respectively. The EC value showed the best diagnostic performance. Conclusion: SWE could improve the accuracy of conventional ERUS in diagnosing the ypT0 stage of rectal cancer after nCRT. It is expected to become a new method to help predict pathological complete responses in clinical practice and provide new evidence for the watch-and-wait approach.

Can rectal MRI and endorectal ultrasound accurately predict the complete response to neoadjuvant immunotherapy for rectal cancer?

Background: Standardized assessments of clinical complete response (cCR) to neoadjuvant chemoradiotherapy (nCRT) for rectal cancer have been established, but their utility and accuracy remain unclear. This study aimed to evaluate the clinical diagnostic value of rectal magnetic resonance imaging (MRI) and endorectal ultrasonography (ERUS) for the determination of cCRs after neoadjuvant immunotherapy and to investigate the concordance between cCR and pathological complete response (pCR). Methods: Ninety-four patients with rectal cancer treated with neoadjuvant radiotherapy with or without immunotherapy were included. The sensitivity, specificity, and accuracy of each evaluation method were calculated. Results: Combined MRI and ERUS assessments found cCR in seven of the 94 patients in our cohort. In the non-immunotherapy group, the sensitivity, specificity, and accuracy of MRI for diagnosing cCR were 50.0%, 85.2%, and 77.1%, respectively, whereas those of ERUS were 50.0%, 92.6%, and 82.9%, respectively; those of combined MRI and ERUS were 25.0%, 96.3%, and 87.5%, respectively. In the immunotherapy group, the sensitivity, specificity, and accuracy with which MRI identified CR were 51.7%, 76.7%, and 64.4%, respectively; those of ERUS were 13.8%, 90.0%, and 52.5%, respectively, and those of combined MRI and ERUS were 10.3%, 96.7%, and 54.2%, respectively. We also found that 32 of 37 patients with pCR did not meet the cCR evaluation criteria. Of these pCR patients, 78.4% (29/37) received immunotherapy. In the entire cohort, there were five pCRs among the seven cCRs. Of the four cCRs that occurred in the immunotherapy group, three were pCRs. Conclusions: Rectal MRI and/or ERUS did not provide sufficiently accurate assessments of cCR in patients with rectal cancer receiving neoadjuvant therapy, especially immunotherapy, and cCR did not predict pCR.

Contemporary management of rectal cancer.

The management of rectal cancer has undergone significant changes over the past 50 years, and this has been associated with major improvements in overall outcomes and quality of life. From standardization of total mesorectal excision to refinements in radiation delivery and shifting of chemoradiotherapy treatment to favor a neoadjuvant approach, as well as the development of targeted chemotherapeutics, these management strategies have continually aimed to achieve locoregional and systemic control while limiting adverse effects and enhance overall survival. This article highlights evolving aspects of rectal cancer therapy including improved staging modalities, total neoadjuvant therapy, the role of short-course and more selective radiotherapy strategies, as well as organ preservation. We also discuss the evolving role of minimally invasive surgery and comment on lateral pelvic lymph node dissection. Key message: Rectal cancer management is constantly evolving through refinements in radiation timing and delivery, modification of chemoradiotherapy treatment schedules, and increasing utilization of minimally invasive surgical techniques and organ preservation strategies. This manuscript aims to provide a synopsis of recent changes in the management of rectal cancer, highlighting contemporary modifications in neoadjuvant approaches and surgical management to enhance the knowledge of surgeons who care for this challenging population.

Comparing three-dimensional endorectal ultrasound and magnification chromoendoscopy for early rectal neoplasia invasion depth assessment.

INTRODUCTION: Accurate assessment of invasion depth of early rectal neoplasms is essential for optimal therapy. We aimed to compare three-dimensional endorectal ultrasound (3D-ERUS) with magnification chromoendoscopy (MCE) regarding their accuracy in assessing parietal invasion depth (T). METHODS: Patients with middle and distal rectum neoplasms were prospectively included. Two providers blinded to each other's assessment performed 3D-ERUS and MCE, respectively. The T stage assessed through ERUS was compared to the MCE evaluation. The results were compared to the surgical specimen anatomopathological report. Sensitivity, specificity, accuracy, positive (PPV), and negative (NPV) predictive values were calculated for the T stage and for the final therapy (local excision or radical surgery). RESULTS: In 8 years, 70 patients were enrolled, and all underwent both exams. MCE and ERUS showed an accuracy of 94.3% and 85.7%, sensitivity of 83.7 and 93.3%, specificity of 96.4 and 83.6%, PPV of 86.7 and 60.9%, and NPV of 96.4 and 97.9%, respectively. Kappa for T stage assessed through ERUS was 0.64 and 0.83 for MCE. CONCLUSION: MCE and 3D-ERUS had good diagnostic performance, but the endoscopic method had higher accuracy. Both methods reliably assessed lesion extension, circumferential involvement, and distance from the anal verge.

Colitis cystica profunda: A report of two cases.

Colitis cystica profunda (CCP) is a rare benign disease characterized by mucus-filled cysts in the submucosa. Endoscopic, radiological and histological examinations are not highly specific, which can lead to misdiagnosis, resulting in unnecessary radical surgical resection. This report presents two cases of CCP with their clinical and imaging features.

Utility of Machine Learning Algorithms in Predicting Preoperative Lymph Node Metastasis in Patients With Rectal Cancer Based on Three-Dimensional Endorectal Ultrasound and Clinical and Laboratory Data.

BACKGROUND: We aimed to investigate the value of a machine learning (ML) algorithm in the preoperative prediction of lymph node metastasis in patients with rectal cancer. METHODS: Based on the histopathological results, 126 rectal cancer patients were divided into two groups: lymph node metastasis-positive and metastasis-negative groups. We collected clinical and laboratory data, three-dimensional endorectal ultrasound (3D-ERUS) findings, and parameters of the tumor for between-group comparisons. We constructed a clinical prediction model based on the ML algorithm, which demonstrated the best diagnostic performance. Finally, we analyzed the diagnostic results and processes of the ML model. RESULTS: Between the two groups, there were significant differences in serum carcinoembryonic antigen (CEA) levels, tumor length, tumor breadth, circumferential extent of the tumor, resistance index (RI), and ultrasound T-stage (P < 0.05). The extreme gradient boosting (XGBoost) model had the best comprehensive diagnostic performance for predicting lymph node metastasis in patients with rectal cancer. Compared with experienced radiologists, the XGBoost model showed significantly higher diagnostic value in predicting lymph node metastasis; the area under curve (AUC) value of the receiver operating characteristic (ROC) curve of the XGBoost model and experienced radiologists was 0.82 and 0.60, respectively. CONCLUSIONS: Preoperative predictive utility in lymph node metastasis was demonstrated by the XGBoost model based on the 3D-ERUS finding and related clinical information. This could be useful in guiding clinical decisions on the selection of different treatment strategies.

Restaging rectal cancer following neoadjuvant chemoradiotherapy.

Correct tumour restaging is pivotal for identifying the most personalised surgical treatment for patients with locally advanced rectal cancer undergoing neoadjuvant therapy, and works to avoid both poor oncological outcome and overtreatment. Digital rectal examination, endoscopy, and pelvic magnetic resonance imaging are the recommended modalities for local tumour restaging, while chest and abdominal computed tomography are utilised for the assessment of distant disease. The optimal length of time between neoadjuvant treatment and restaging, in terms of both oncological safety and clinical effectiveness of treatment, remains unclear, especially for patients receiving prolonged total neoadjuvant therapy. The timely identification of patients who are radioresistant and at risk of disease progression remains challenging.

Diagnostic performance of endorectal ultrasound combined with shear wave elastography for rectal tumors staging.

OBJECTIVE: This study aims to analyze the performance of endorectal ultrasound (ERUS) combined with shear wave elastography (SWE) for rectal tumor staging. METHODS: Forty patients with rectal tumors who had surgery were enrolled. They underwent ERUS and SWE examinations before surgery. Pathological results were used as the gold standard for tumor staging. The stiffness values of the rectal tumor, peritumoral fat, distal normal intestinal wall, and distal perirectal fat were analyzed. The diagnostic accuracy of ERUS stage, tumor SWE stage, ERUS combined with tumor SWE stage, and ERUS combined with peritumoral fat SWE stage were compared and evaluated by receiver operating characteristic (ROC) curve to select the best staging index. RESULTS: From T1 to T3 stage, the maximum elasticity (Emax) of the rectal tumor increased gradually (p < 0.05). The cut-off values of adenoma/T1 and T2, T2 and T3 tumors were 36.75 and 85.15kPa, respectively. The diagnostic coincidence rate of tumor SWE stage was higher than that of ERUS stage. Overall diagnostic accuracy of ERUS combined with peritumoral fat SWE Emax restaging was significantly higher than that of ERUS. CONCLUSIONS: ERUS combined with peritumoral fat SWE Emax for tumor restaging can effectively distinguish between stage T2 and T3 rectal tumors, which provides an effective imaging basis for clinical decisions.

Malignant transformation of rectal endometriosis: Preoperative diagnosis by endorectal ultrasound guided biopsy.

The prevalence of malignant transformation of endometriotic lesions is estimated between 0.3% and 1%. Malignant transformations of endometriosis occur in the colorectum is rarer, accounting for 0.25%. Because the malignant transformation of colorectal endometriosis rarely involves mucosa, it is difficult to obtain abnormal tissue by routine endoscopic biopsy. In this case, we evaluated a patient with a rectal mass by endorectal ultrasound (ERUS) and performed endorectal ultrasound-guided biopsy (EGB). Malignant transformations of endometriosis were confirmed by histological result. For patients with rectal tumors but with negative findings on colonoscopy and biopsy, ERUS and EGB contribute to preoperative diagnosis.

The Value of Magnetic Resonance Imaging and Endorectal Ultrasound for the Accurate Preoperative T-staging of Rectal Cancer.

Magnetic resonance imaging (MRI) and endorectal ultrasound (ERUS) are essential imaging modalities to assess the depth of tumour invasion (T-staging) in rectal cancer preoperative staging. Accurate T-staging is critical for rectal cancer prognosis and has substantial importance in the determination of appropriate treatment strategies for rectal tumours. There seems to be a knowledge gap in the published literature regarding the most appropriate imaging modality for the preoperative staging of rectal cancer. The purpose of this study was to determine the most appropriate imaging technique for the preoperative T-staging of rectal cancer by comparing the MRI and ERUS staging. In this study, we performed a literature review of studies published in the last 10 years and compared the accuracy, sensitivity, and specificity of ERUS and MRI for the preoperative T-staging of rectal cancer with the aim of identifying the most appropriate imaging modality. The studies reviewed were selected by a rigorous literature search of academic databases. Three electronic databases (PubMed, CINAHL, and Scopus) were searched, and articles were identified. Further rescreening of the articles for those that met the inclusion criteria and searching of the citations of the articles produced eleven journal articles used in this research. Endorectal ultrasound produces accurate results for the T-staging of early rectal cancer, particularly T1 and T2, and has the ability to show the layers of the bowels more clearly in early-stage rectal cancer. However, MRI shows more accurate results for the staging of locally advanced tumours such as advanced T3 and T4 and is particularly important when estimating tumour invasion into the mesorectum, which is very important for the prognostication and survival of patients with rectal cancer. MRI has low accuracy for differentiating early T3 tumours from T1 or T2 with desmoplastic reactions, and therefore, is more likely to overstage these tumours.

Endorectal Ultrasound Shear-Wave Elastography of Complex Rectal Adenoma and Early Rectal Cancer.

Purpose: To investigate the diagnostic performance of endorectal ultrasound (ERUS), shear-wave elastography (SWE), and magnetic resonance imaging (MRI) in patients with a complex rectal adenoma or an early rectal cancer, i.e., T1 or T2 adenocarcinoma in a clinical setting, and to evaluate the association between SWE and stromal fraction (SF) and apparent diffusion coefficient (ADC) and SF. Method: This prospective study included patients undergoing ERUS and SWE for a rectal tumor subsequently confirmed by histopathology to be an adenoma or a T1 or T2 adenocarcinoma. The accuracy of the imaging methods was assessed by comparing the T category as determined by ERUS and MRI with histopathology, which served as the gold standard. SF was assessed on surgical specimens. Results: A total of 86 patients were included. Of these, 62 patients had adenomas and 24 patients had carcinomas, of which 11 were T1 tumors and 13 were T2 tumors. ERUS and MRI yielded sensitivity, specificity, and accuracy of 0.79 and 0.73, 0.95 and 0.90, and 0.86 and 0.78, respectively, for discrimination between benign and malignant lesions. The area under the receiver operating characteristics curve for SWE was 0.88, and with a cut-off value of 40 kPa the sensitivity, specificity, and accuracy were 0.79, 0.89, and 0.86, respectively. There was a positive correlation between SF and SWE with a p-value of <0.001 and a negative correlation between SF and ADC with a p-value of 0.011. Conclusion: Both ERUS and MRI classified T categories with a high accuracy; however, ERUS classified more adenomas correctly than MRI. In this small population, SWE could differentiate an adenoma from early carcinoma. SF was correlated with both SWE and ADC, as increasing SF tended to yield higher SWE and lower ADC values.

Concordance and survival implications of preoperative subclassification of T3 rectal cancers by depth of mesorectal invasion using a 5-mm cut-off point with endorectal ultrasound and magnetic resonance imaging.

Background: Validated rectal cancer staging groups T3 tumours in a single stage and depth of mesorectal invasion subclassification is not standard practice. Our aim is to report concordance between magnetic resonance imaging (MRI) and endorectal ultrasound (ERUS) for preoperative staging of T3 rectal tumours using a 5-mm cut-off point and possible survival implications. Methods: Prospective cohort study including patients staged preoperatively as cT3 by ERUS or magnetic resonance imaging. The maximum depth of penetration beyond the outer longitudinal muscle layer was measured according to a 5-mm cut-off point. Concordance rate and Kappa coefficient were calculated for both techniques. Primary end-points were disease free survival and overall survival (OS) for both groups. Results: A total of 97 patients were included. Disease-free survival in depth of mesorectal invasion ≤5 and >5 mm measured by ERUS was 130.80 (119.20-142.30) vs. 88.38 (56.13-120.64) months (P=0.020), respectively, and 129.90 (117.90-141.90) vs. 93.60 (64.50-122.70) months (P=0.045) when measured by magnetic resonance imaging. Depth of mesorectal invasion ≤5 mm measured by ERUS and MRI was a prognostic factor for both OS [ERUS P=0.009; MRI P=0.019] and DFS (ERUS P=0.026; MRI P=0.054) after Cox regression analysis. Conclusions: T3 subclassification above and below 5mm is feasible by ERUS, shows good concordance with validated magnetic resonance and can easily be incorporated into the diagnostic workup for these patients with possible survival implications.

Judgment of benign and early malignant colorectal tumors from ultrasound images with deep multi-View fusion.

BACKGROUND AND OBJECTIVE: Colorectal cancer (CRC) is currently one of the main cancers world-wide, with a high incidence in the elderly. In the diagnosis of CRC, endorectal ultrasound plays an important role in judging benign and early malignant tumors. However, malignant tumors in the early-stage are not easy to identify visually and experts usually seek help from multi-view images, which increases the workload and also exists a certain probability of misdiagnosis. In recent years, with the widespread use of deep learning methods in the analysis of medical images, it becomes necessary to design an effective computer-aided diagnosis (CAD) system of CRC based on multi-view endorectal ultrasound images. METHOD: In this study, we proposed a CAD system for judging benign and early malignant colorectal tumors, and constructed the first multi-view ultrasound image dataset of CRC to validate our algorithm. Our system is an end-to-end model based on a deep neural network (DNN) which includes a feature extraction module based on dense blocks, a multi-view fusion module, and a Multi-Layer Perception-based classifier. A center loss was used for the first time in CAD tasks, to optimize our model. RESULT: On the constructed dataset, the proposed system surpasses expert diagnosis in accuracy, sensitivity, specificity, and F1-score. Compared with the popular deep classification networks and other CAD methods, the algorithm has reached the best performance. Comparative experiments using different feature extraction methods, different view fusion strategies, and different classifiers verify the effectiveness of each part of the algorithm. CONCLUSION: We propose a CAD system for judging benign and early malignant colorectal tumors based on DNN, which combines information of ultrasound images from different views for comprehension. On the first CRC multi-view ultrasound image dataset which we constructed, our method outperforms expert diagnosis results and all other methods, and the effectiveness of each part of the system has been verified. Our system has application value in future medical practice on early diagnosis of CRC.

Transperineal core-needle biopsy of a rectal subepithelial lesion guided by endorectal ultrasound after contrast-enhanced ultrasound: A case report.

BACKGROUND: Rectal subepithelial lesions (SELs) are commonly seen in endoscopic examination, generally manifested as bumps with a smooth surface. Precise preoperative diagnoses for rectal SELs are difficult because abnormal tissues are not easily to be obtained by regular endoscopic forceps biopsy. Traditional guidance modalities of preoperative biopsy, including endoscopic ultrasound, computed tomography, and transabdominal ultrasound, are often unsatisfactory. An updated, safe, and effective biopsy guidance method is required. We herein report a new biopsy guidance modality-endorectal ultrasound (ERUS) combined with contrast-enhanced ultrasound (CEUS). CASE SUMMARY: A 32-year-old woman complained of a mass inside the rectovaginal space for 9 years, which became enlarged within 1 year. A rectal SEL detected by endoscopy was suspected to be a gastrointestinal stromal tumor or exophytic uterine fibroid. Pathological diagnosis was difficult because of unsuccessful transabdominal core needle biopsy with insufficient tissues, as well as vaginal hemorrhage. A second biopsy was suggested after multiple disciplinary treatment discussion, which referred to a transperineal core needle biopsy (CNB) guided by ERUS combined with CEUS. Adequate samples were procured and rectal gastrointestinal stromal tumor was proved to be the pathological diagnosis. Imatinib was recommended for first-line therapy by multiple disciplinary treatment discussion. After the tumor shrunk, resection of the rectal gastrointestinal stromal tumor was performed through the posterior vaginal wall. Adjuvant therapy was applied and no recurrence or metastasis has been found by the last follow-up on December 13, 2019. CONCLUSION: Transperineal CNB guided by ERUS and CEUS is a safe and effective preoperative biopsy of rectal SELs yet with some limitations.

Application Value of Shear Wave Elastography in the Evaluation of Tumor Downstaging for Locally Advanced Rectal Cancer After Neoadjuvant Chemoradiotherapy.

OBJECTIVES: The aim of this study was to assess the application value of shear wave elastography in the evaluation of tumor downstaging for locally advanced rectal cancer after neoadjuvant chemoradiotherapy. METHODS: A retrospective analysis was conducted using data from patients with locally advanced rectal cancer treated in our hospital who received endorectal ultrasound (ERUS) and shear wave elastographic examinations before and after chemoradiotherapy. The cases were grouped according to the postoperative pathologic tumor-staging scores. The lesions were divided into 2 groups: 1 showing and the other not showing tumor downstaging. The efficacy of ERUS in diagnosis of tumor downstaging was calculated. The differences in the mean and maximum values of the Young modulus of the lesions before and after chemoradiotherapy between the groups were calculated and compared. Receiver operating characteristic curves were constructed by using the differences in the 2 kinds of values of the Young modulus. RESULTS: The mean and maximum values of the Young modulus before and after chemoradiotherapy were significantly different (P < .05). The differences in the mean and maximum values of the Young modulus of rectal lesions between groups were statistically significant (P < .05). The results of the receiver operating characteristic curve showed that a difference in the mean value at 34.7 kPa was the optimal diagnostic threshold. Compared with ERUS, this standard showed a significant difference in diagnosis of tumor downstaging (P < .05). CONCLUSIONS: Shear wave elastography is an effective ultrasound elastographic technique to assist ERUS in evaluating lesions after chemoradiotherapy in rectal cancer. It can improve the diagnostic efficacy of tumor downstaging and provide effective imaging conclusions for clinical decision making.

Correlation Between Endorectal Ultrasound and Magnetic Resonance Imaging for Predicting the Circumferential Resection Margin in Patients With Mid-Low Rectal Cancer Without Preoperative Chemoradiotherapy.

OBJECTIVES: To assess the correlation between endorectal ultrasound (ERUS) and magnetic resonance imaging (MRI) in predicting the circumferential resection margin (CRM) status of patients with mid-low rectal cancer without preoperative chemoradiotherapy. METHODS: Twenty patients with rectal cancer who did not receive preoperative chemoradiotherapy and underwent ERUS and MRI examinations before total mesorectal excision from May 2018 to April 2019 were included in this study. The patient and tumor characteristics, lymph nodes, tumor stages, ERUS and MRI predictors of the CRM status, and postoperative pathologic results were recorded. The closest distance between the deepest portion of lesion invasion and the mesorectal fascia was independently measured on MRI and ERUS images by 2 observers. The observers were blinded to the pathologic results. Measurements from ERUS and MRI were compared. RESULTS: The mean distance between the distal edge of the lesion and the anal verge was 5.7 cm (range, 3.1-8.1 cm). The ERUS and pathologic evaluations of CRM involvement were consistent in 90% of the cases. The MRI and pathologic evaluations of CRM involvement were concordant in 95% of the cases. The Cohen κ coefficient of ERUS and MRI was 0.608 (P = .007). The correlation coefficient of ERUS and MRI for assessing the closest distance from the edge of cancer invasion to the mesorectal fascia was 0.99 (P = .0005). CONCLUSIONS: Endorectal ultrasound and MRI assessments of the preoperative CRM status appear to be highly consistent. Endorectal ultrasound can be used as a complementary tool with MRI to predict the CRM status of patients with mid-low rectal cancer without preoperative chemoradiotherapy.

EFSUMB Recommendations for Gastrointestinal Ultrasound Part 3: Endorectal, Endoanal and Perineal Ultrasound.

This article represents part 3 of the EFSUMB Recommendations and Guidelines for Gastrointestinal Ultrasound (GIUS). It provides an overview of the examination techniques recommended by experts in the field of endorectal/endoanal ultrasound (ERUS/EAUS), as well as perineal ultrasound (PNUS). The most important indications are rectal tumors and inflammatory diseases like fistula and abscesses in patients with or without inflammatory bowel disease (IBD). PNUS sometimes is more flexible and convenient compared to ERUS. However, the technique of ERUS is quite well established, especially for the staging of rectal cancer. EAUS also gained ground in the evaluation of perianal diseases like fistulas, abscesses and incontinence. For the staging of perirectal tumors, the use of PNUS in addition to conventional ERUS could be recommended. For the staging of anal carcinomas, PNUS can be a good option because of the higher resolution. Both ERUS and PNUS are considered excellent guidance methods for invasive interventions, such as the drainage of fluids or targeted biopsy of tissue lesions. For abscess detection and evaluation, contrast-enhanced ultrasound (CEUS) also helps in therapy planning.

Value of endorectal ultrasonography and MRI examination in the preoperative evaluation of T staging and circumferential resection margin of rectal cancer / 中华消化外科杂志

Objective To investigate the value of endorectal ultrasonography (ERUS) and MRI examination in the preoperative evaluation of T staging and circumferential resection margin (CRM) of rectal cancer.Methods The retrospective cross-sectional study was conducted.The clinicopathological data of 193 patients [122 males and 71 females,age (60± 12)years with the range of 26-90 years] who underwent radical resection of rectal cancer at the First Hospital of Jilin University from May 2016 to January 2018 were collected.All patients underwent ERUS and MRI examination before surgery,total mesorectal excision during surgery and postoperative pathological examination.Postoperative pathological results as the gold standard,the sensitivity,specificity in T staging and the CRM diagnostic coincidence rate of rectal carcinoma by ERUS and MRI examination are evaluated.Observation indicators:(1) evaluation of T staging of rectal cancer by ERUS and MRI examination;(2) evaluation of CRM in rectal cancer by ERUS and MRI examination.Measurement data with normal distribution were represented as Mean±SD.Sensitivity,specificity and coincidence rate were calculated by chi-square test of paired fourfold table.McNemar test was used to compare the coincidence rate of T staging between ERUS and MRI examination.Consistency between CRM measurement by ERUS examination and pathological examination of rectal cancer was conducted by Kappa analysis.Fisher exact probability test was used to compare the coincidence rate of positive CRM between ERUS and MRI examination.Results (1) Evaluation of T staging of rectal cancer by ERUS and MRI examination.The overall coincidence rate of T staging of rectal cancer and coincidence rates of T1,T2,T3,T4 staging by ERUS examination were 74.61％ (144/193),93.78％ (181/193),80.83％ (156/193),79.79％ (154/193) and 94.82％ (183/193),respectively.The sensitivity ofT1,T2,T3 and T4 staging was 55.56％ (10/18),77.50％ (31/40),78.46％ (102/130),20.00％ (1/5),and the specificity was 97.71％ (171/175),81.70％ (125/153),82.54％ (52/63),96.81％ (182/188),respectively.The overall coincidence rate of T staging of rectal cancer and coincidence rates of T1,T2,T3,T4 staging by MRI examination were 50.78％ (98/193),90.67％ (175/193),74.09％ (143/193),58.55％ (113/193) and 78.24％ (151/193),respectively.The sensitivity of T1,T2,T3 and T4 staging was 0 (0/18),17.50％ (7/40),68.46％ (89/130),40.00％ (2/5),and the specificity was 100.00％ (175/175),88.89％ (136/153),38.10％ (24/63),79.26％ (149/188),respectively.There was statistically significant difference between the overall coincidence rate of ERUS and MRI examination for T staging of rectal cancer (x2 =8.631,P＜0.05).(2) Evaluation of CRM in rectal cancer by ERUS and MRI examination.The sensitivity and specificity of positive CRM evaluation of rectal cancer by ERUS examination were 100.00％ (5/5) and 97.34％ (183/188) respectively,and the coincidence rate with results of pathological examination was 97.41％ (188/193),showing a high consistency between positive CRM evaluation of rectal cancer by ERUS examination and pathological examination (Kappa value =0.655,P ＜ 0.05).The sensitivity and specificity of positive CRM evaluation of rectal cancer by MRI examination were 40.00％ (2/5) and 92.02％ (173/188),and the coincidence rate with pathological examination was 90.67％ (175/193),respectively,showing a high consistency between positive CRM evaluation of rectal cancer by MRI and pathological examination (Kappa value =0.206,P＜0.05).There were statistically significant differences in the diagnostic coincidence rate and specificity of CRM positive evaluation for rectal cancer between ERUS and MRI examination (x2 =5.896,P＜0.05).Conclusion ERUS examination has a high coincidence rate in the preoperative T staging of rectal cancer and a high consistency between positive CRM evaluation of rectal cancer with pathological examination,which are superior to MRI examination in the two aspects.