How useful is rectal endosonography in the staging of rectal cancer?

Current update on the role of endoanal ultrasound: a primer for radiologists

Endoanal ultrasound (EAUS) is a valuable imaging modality for the evaluation of anal and perianal pathologies. It provides detailed information about the anatomy and physiology of the anorectal region and has been used in pre-and post-operative settings of anorectal pathologies. EAUS is not only useful in the evaluation of benign pathologies but also in loco-regional staging of anal and rectal tumors. EAUS has several advantages over MRI, including reduced cost, better patient tolerance, and improved scope of application in patients with contraindications to MRI. Despite its benefits, EAUS is not widely performed in many centers across the globe. This article aims to educate radiologists, trainees, and surgeons about the indications, contraindications, patient preparation, imaging technique, and findings of EAUS. We will also highlight the technical difficulties, diagnostic challenges, and procedural complications encountered during EAUS, along with a comparative analysis of EAUS with other imaging approaches.

Value of biplane transrectal ultrasonography plus micro-flow imaging in preoperative T staging and rectal cancer diagnosis in combination with CEA/CA199 and MRI

BACKGROUND

Rectal cancer is one of the most common malignant tumors and has a high incidence rate and fatality rate. Accurate preoperative T staging of rectal cancer is critical for the selection of appropriate rectal cancer treatment. Various pre-operative imaging methods are available, and the identification of the most accurate method for clinical use is essential for patient care. We investigated the value of biplane transrectal ultrasonography (TRUS) combined with MFI in preoperative staging of rectal cancer and explored the value of combining TRUS plus MFI with CEA/CA199 and MRI.

METHODS

A total of 87 patients from Daping Hospital with rectal cancer who underwent TRUS examination plus MFI were included. Grades of MFI were determined by Alder classification. Among the total patients, 64 underwent MRI and serum CEA/CA199 tests additionally within one week of TRUS. Pathological results were used as the gold standard for cancer staging. Concordance rates between TRUS, MRI, and CEA/CA199 for tumors at different stages were compared.

RESULTS

There were no significant differences between the Alder classification and pathological T staging. The concordance rate of TRUS and MFI for rectal cancer T staging was 72.4% (K = 0.615, p < 0.001). Serum CEA and CA199 levels were significantly different in tumors at different stages and increased progressively by pathological stage (p < 0.001); the accuracy rate was 71.88% (K = 0.599, p < 0.001), while that of MRI was 51.56% (K = 0.303, p < 0.001), indicating that TRUS had higher consistency in the preoperative T staging of rectal cancer. The combination of TRUS, MRI, and CEA/CA199 yielded an accuracy rate of 90.6%, which was higher than that of any method alone.

CONCLUSIONS

Preoperative T staging of rectal cancer from biplane TRUS plus MFI was highly consistent with postoperative pathological T staging. TRUS combined with MRI and serum CEA/CA199 had a greater value in the diagnosis of rectal cancer and a higher diagnostic rate than any examination alone.

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.

Endoluminal ultrasound versus magnetic resonance imaging in assessment of rectal cancer after neoadjuvant therapy

BACKGROUND

Accurate rectal tumor staging guides the choice of treatment options. EUS and MRI are the main modalities for staging.

AIM OF THE WORK

To compare the performance of EUS and MRI for loco-regional staging of anorectal cancer after neo-adjuvant therapy.

METHODS

Seventy-three (37 male, 36 female) patients with rectal cancer after neo-adjuvant chemoradiotherapy were enrolled. Histopathological staging after surgery were used as reference for comparing the yield of loco-regional staging for EUS and MRI. EUS and MRI were done 1 month after completion of neo-adjuvant therapy.

RESULTS

Regarding post-surgical T staging, eight patients had early tumor (T2 = 16 and T1 = 9) and thirty six were locally advanced (T3 = 36), while N staging, forty patients with negative nodes and 33 were positive (N1 = 22 and N2 = 11). Comparing EUS to MRI, it showed a higher sensitivity (95.7% vs. 78.7%), specificity (84.6% vs. 68.0%) and accuracy (91.8% vs. 75.3%) for staging early and locally advanced tumor. Also, it had a higher sensitivity (78.8% vs. 69.7%), specificity (75.0% vs. 65.0%) and accuracy (76.7% vs. 67.1%) for detection of lymph nodes.

CONCLUSION

EUS appears to be more accurate than MRI in loco-regional staging of rectal carcinoma after neo-adjuvant therapy.

Clinical benefits of oral capecitabine over intravenous 5-fluorouracyl regimen in case of neoadjuvant chemoradiotherapy followed by surgery for locally advanced rectal cancer

Background: During the last decade, one of the most important treatment options for locally advanced, potencially resectable rectal tumours was neoadjuvant chemoradiotherapy (CRT) followed by surgery. Methods: Effects of the neoadjuvant treatment on surgical outcomes were retrospectively analysed in 185 patients with stage T2-T4 and N0-2, resectable rectal tumour among two patient groups defined by radiosensitizer agents. Group 1 (n = 94) involved radiotherapy (RT) with 50.4 Gy total dose (25 × 1.8 Gy + 3 × 1.8 Gy tumour bed boost), and intravenous 5-fluorouracil (5-FU) (350 mg/m²) with leucovorin (20 mg/m²) on the 1-5 and 21-25 days, while Group 2 (n = 91) RT and orally administrated capecitabine (daily 2 × 825 mg/m²) on RT days. Surgery was carried out after 8-10 weeks. Side effects, perioperative complications, type of surgery, number of removed regional lymph nodes, resection margins and tumour regression grade (TRG) were analysed. Results: More favourable side effects were observed in Group 2. Despite the same rate of diarrhoea (Group 1 vs. Group 2: 54.3% vs. 56.0%), Grade 2-3 diarrhoea ratio was lower (p = 0.0352) after capecitabine (Group 2). Weight loss occurred in 17.0% and 2.2% (p = 0.00067), while nausea and vomiting was described in 38.3% and 15.4% (p = 0.00045) with 5-FU treatment and capecitabine respectively. Anaemia was observed in 33.0% and 22.0% (p = 0.0941). Complete tumour regression occurred in 25.3% after oral- and 13.8% after intravenous treatment (p = 0.049). Ratio of sphincter preservation was higher with laparoscopy than open surgery (72.3% vs. 39.7%) (p = 0.00001). Conclusion: The study confirms advantages of neoadjuvant chemoradiotherapy with oral capecitabine for rectal tumours, such as more favourable side effect profile and overall clinical outcome, with increased rate of complete tumour regression.

Endorectal ultrasound radiomics in locally advanced rectal cancer patients: despeckling and radiotherapy response prediction using machine learning

PURPOSE

The current study aimed to evaluate the association of endorectal ultrasound (EUS) radiomics features at different denoising filters based on machine learning algorithms and to predict radiotherapy response in locally advanced rectal cancer (LARC) patients.

METHODS

The EUS images of forty-three LARC patients, as a predictive biomarker for predicting the treatment response of neoadjuvant chemoradiotherapy (NCRT), were investigated. For despeckling, the EUS images were preprocessed by traditional filters (bilateral, wiener, lee, frost, median, and wavelet filters). The rectal tumors were delineated by two readers separately, and radiomics features were extracted. The least absolute shrinkage and selection operator were used for feature selection. Classifiers including logistic regression (LR), K-nearest neighbor (KNN), support vector machine (SVM), random forest, naive Bayes, and decision tree were trained using stratified fivefold cross-validation for model development. The area under the curve (AUC) of the receiver operating characteristic curve followed by accuracy, precision, sensitivity, and specificity were obtained for model performance assessment.

RESULTS

The wavelet filter had the best results with means of AUC: 0.83, accuracy: 77.41%, precision: 82.15%, and sensitivity: 79.41%. LR and SVM by having AUC: 0.71 and 0.76; accuracy: 70.0% and 71.5%; precision: 75.0% and 73.0%; sensitivity: 69.8% and 80.2%; and specificity: 70.0% and 60.9% had the highest model's performance, respectively.

CONCLUSION

This study demonstrated that the EUS-based radiomics model could serve as pretreatment biomarkers in predicting pathologic features of rectal cancer. The wavelet filter and machine learning methods (LR and SVM) had good results on the EUS images of rectal cancer.

Practical approach to linear endoscopic ultrasound examination of the rectum and anal canal

Standard endosonographic examination of the rectal area is usually performed with radial endoscopic ultrasound (EUS). However, in recent years, widespread availability of linear EUS for assessing various anatomical regions in the gastrointestinal tract has facilitated its use in the assessment of anorectal disorders. Currently, many rectal and anal diseases, including perianal abscesses, fistulae, polyps, and neoplastic lesions, can be well-visualized and evaluated with linear EUS. The aim of this review is to shed light on the anatomy and systematic examination of the anorectal region with linear EUS and clinical implications for different anorectal pathologies.

Endorectal Ultrasound and Magnetic Resonance Imaging for Rectal Cancer Staging: A Modern Multimodality Approach

Preoperative staging represents a crucial point for the management, type of surgery, and candidacy for neoadjuvant therapy in patient with rectal cancer. The most recent clinical guidelines in oncology recommend an accurate preoperative evaluation in order to address early and advanced tumors to different therapeutic options. In particular, potential pitfalls may occur in the assessment of T3 tumors, which represents the most common stage at diagnosis. The depth of tumor invasion is known to be an important prognostic factor in rectal carcinoma; as a consequence, the T3 imaging classification has a substantial importance for treatment strategy and patient survival. However, the differentiation between tumor invasion of perirectal fat and mesorectal desmoplastic reactions remains a main goal for radiologists. Magnetic resonance imaging (MRI) is actually considered as the best imaging modality for rectal cancer staging. Although the endorectal ultrasound (ERUS) is the preferred staging method for early tumors, it could also be useful in identifying perirectal fat invasion. Moreover, the addiction of diffusion weighted imaging (DWI) improves the diagnostic performance of MRI in rectal cancer staging by adding functional information about rectal tumor and adjacent mesorectal tissues. This study investigated the diagnostic performance of conventional MRI alone, in combination with the DWI technique and ERUS in order to assess the best diagnostic imaging combination for rectal cancer staging.

Imaging and Management of Rectal Cancer

High-resolution phased array external magnetic resonance imaging (MRI) is the first investigation of choice in rectal cancer for local staging, both in the primary and restaging situations. Use of MRI helps differentiate between those with good prognosis, which can be offered upfront surgery and the poor prognostic cases where treatment intensification is needed. MRI identified poor prognostic factors are threatened or involved mesorectal fascia, T3 tumors with >5 mm extramural spread, those with extramural vascular invasion, pelvic sidewall nodes and mucinous tumors. At restaging, use of MRI helps evaluate response and an MR tumor regression grading system is being evaluated. Complete response seen on clinical examination and endoscopy, needs confirmation on MRI using both T2-weighted and diffusion-weighted sequences to justify a "watch and wait" approach. In this subset of patients, MRI also plays a role in monitoring and detecting early regrowth. In those with partial response, MRI helps define surgical margins and can be used as a roadmap to decide between sphincter preserving surgeries and radical sphincter sacrificing surgeries; pelvic exenteration and pelvic sidewall lymph node dissection. Poor responders on MRI may benefit from adjuvant chemotherapy. Use of MRI thus helps in individualizing treatment in rectal cancer.

Preoperative prediction of tumour deposits in rectal cancer by an artificial neural network-based US radiomics model

OBJECTIVE

To develop a machine learning-based ultrasound (US) radiomics model for predicting tumour deposits (TDs) preoperatively.

METHODS

From December 2015 to December 2017, 127 patients with rectal cancer were prospectively enrolled and divided into training and validation sets. Endorectal ultrasound (ERUS) and shear-wave elastography (SWE) examinations were conducted for each patient. A total of 4176 US radiomics features were extracted for each patient. After the reduction and selection of US radiomics features , a predictive model using an artificial neural network (ANN) was constructed in the training set. Furthermore, two models (one incorporating clinical information and one based on MRI radiomics) were developed. These models were validated by assessing their diagnostic performance and comparing the areas under the curve (AUCs) in the validation set.

RESULTS

The training and validation sets included 29 (33.3%) and 11 (27.5%) patients with TDs, respectively. A US radiomics ANN model was constructed. The model for predicting TDs showed an accuracy of 75.0% in the validation cohort. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and AUC were 72.7%, 75.9%, 53.3%, 88.0% and 0.743, respectively. For the model incorporating clinical information, the AUC improved to 0.795. Although the AUC of the US radiomics model was improved compared with that of the MRI radiomics model (0.916 vs. 0.872) in the 90 patients with both ultrasound and MRI data (which included both the training and validation sets), the difference was nonsignificant (p = 0.384).

CONCLUSIONS

US radiomics may be a potential model to accurately predict TDs before therapy.

KEY POINTS

• We prospectively developed an artificial neural network model for predicting tumour deposits based on US radiomics that had an accuracy of 75.0%. • The area under the curve of the US radiomics model was improved than that of the MRI radiomics model (0.916 vs. 0.872), but the difference was not significant (p = 0.384). • The US radiomics-based model may potentially predict TDs accurately before therapy, but this model needs further validation with larger samples.

The accuracy of trans rectal ultrasonography (TRUS) in early-stage rectal cancer or benign adenomas

Background: Screening for colorectal cancer in Denmark has resulted in more patients being diagnosed with benign adenomas and early-stage rectal cancer. In general, TRUS is accepted as a good modality for evaluating the above mentioned before deciding on surgery. Objective: To investigate the accuracy of TRUS in a clinical setting at the Region Hospital in Herning, Denmark. Study design: Retrospective cohort study from January 2016 to June 2018. Methods: Quantitative method. The cohort (117 patients) was recruited by searching for specific procedure codes. Data were collected by going through the electronic patient files. Results: TRUS predicted T0, T1, T2 and T3 with an accuracy of 91%, 35%, 43% and 20% respectively and an overall accuracy of 68%. A weighted Cohens kappa value of 0.30 (p  ≤  .05). TRUS differentiated between T0/T1 with a sensitivity of 70%, specificity of 85% and an accuracy of 85% and kappa value of 0.44 (p  ≤  .05). Conclusion: TRUS can with great precision establish whether the tumor is benign so correct local treatment can be instituted.

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.

The Optimal Application of Transrectal Ultrasound in Staging of Rectal Cancer Following Neoadjuvant Therapy: A Pragmatic Study for Accuracy Investigation

Background: Transrectal ultrasound (TRUS) is a cost-effective test for preoperative assessment of rectal cancer. However, whether the accuracy of TRUS staging is correlated with tumor location remains obscured. This study is designed to explore their relationship and confirm an optimal application of TRUS in rectal cancer restaging.

Methods: From 2005 to 2011, rectal cancer patients with TRUS data were retrospectively reviewed. Patients were divided into five groups according to tumor-involved rectal segment (SEG) above the anal verge: SEG I 1-3cm, II 3-6cm, III 6-9cm, IV 9-12cm, and V 12-16cm. The accuracy and long-term outcomes of tumor staging were compared between ultrasonographic and pathological stages.

Results: 219 patients were included, with 55 (25.1%) in SEG I, 123 (56.2%) in SEG II, 32 (14.6%) in SEG III, 4 (1.8%) in SEG IV and 5 (2.3%) in SEG V. The overall accuracy of TRUS staging was remarkably superior to clinical staging by CT (64.8% vs. 34.7%, P<0.001), with 70.3% and 82.2% for ultrasonographic T and N stages respectively. The accuracy of TRUS reached its peak value when tumors were located in SEG II. The 5-year overall survival had no significant difference between TRUS and pathology staging for all stages. A cox regression analysis indicated that high levels of CEA and tumor location were risk factors of inaccurate staging.

Conclusions: TRUS is still a valuable examination for restaging of rectal cancer after neoadjuvant therapy. The application of TRUS would be optimal for rectal cancer located 3-6cm above the anal verge.

Role of ultrasound in colorectal diseases

Ultrasound is an undervalued non-invasive examination in the diagnosis of colonic diseases. It has been replaced by the considerably more expensive magnetic resonance imaging and computed tomography, despite the fact that, as first examination, it can usefully supplement the diagnostic process. Transabdominal ultrasound can provide quick information about bowel status and help in the choice of adequate further examinations and treatment. Ultrasonography, as a screening imaging modality in asymptomatic patients can identify several colonic diseases such as diverticulosis, inflammatory bowel disease or cancer. In addition, it is widely available, cheap, non-invasive technique without the use of ionizing radiation, therefore it is safe to use in childhood or during pregnancy, and can be repeated at any time. New ultrasound techniques such as elastography, contrast enhanced and Doppler ultrasound, mini-probes rectal and transperineal ultrasonography have broadened the indication. It gives an overview of the methodology of various ultrasound examinations, presents the morphology of normal bowel wall and the typical changes in different colonic diseases. We will pay particular attention to rectal and transperineal ultrasound because of their outstanding significance in the diagnosis of rectal and perineal disorders. This article seeks to overview the diagnostic impact and correct indications of bowel ultrasound.

Endoscopic ultrasound for staging of colonic cancer proximal to the rectum: A systematic review and meta-analysis

Background and Objectives:

Treatment of colonic cancer patients is highly dependent on the depth of tumor invasion (T-stage) as well as the extension of lymph node involvement (N-stage). We aimed to systematically review the accuracy of endoscopic ultrasound (EUS) for staging of colonic cancer proximal to the rectum.

Patients and Methods:

Men and women with colonic adenocarcinomas were included in the study. EUS staging was compared to histopathology as the gold standard. Outcome measures were T- and N-staging accuracies. Articles were searched in PubMed, Web of Science, The Cochrane Library, and EMBASE.

Results:

Six studies were identified comparing EUS staging of colonic cancer to histopathology. The pooled-staging sensitivity and specificity were 0.90 and 0.98 for T1 tumors, 0.67 and 0.96 for T2 tumors, and 0.97 and 0.83 for T3/T4 tumors, respectively. Sensitivity and specificity for N + disease were 0.59 and 0.78, respectively.

Conclusions:

EUS is a feasible method for T-staging of cancers of the colon proximal to the rectum. The accuracy of lymph node staging needs to be verified by prospective multicenter studies including larger patient populations.

Rectal Tumour Staging with Endorectal Ultrasound: Is There Any Difference between Western and Eastern European Countries?

Background. Rectal tumour management depends highly on locoregional extension. Rectal endoscopic ultrasound (ERUS) is a good alternative to computed tomography and magnetic resonance imaging. However, in Hungary only a small amount of rectal tumours is examined with ERUS. Methods. Our retrospective study (2006–2012) evaluates the diagnostic accuracy of ERUS and compares the results, the first data from Central Europe, with those from Western Europe. The effect of neoadjuvant therapy, rectal probe type, and investigator's experience were also assessed. Results. 311 of the 647 ERUS assessed locoregional extension. Histological comparison was available in 177 cases: 67 patients underwent surgery alone; 110 received neoadjuvant chemoradiotherapy (CRT); ERUS preceded CRT in 77 and followed it in 33 patients. T-staging was accurate in 72% of primarily operated patients. N-staging was less accurate (62%). CRT impaired staging accuracy (64% and 59% for T- and N-staging). Rigid probes were more accurate (79%). At least 30 examinations are needed to master the technique. Conclusions. The sensitivity of ERUS complies with the literature. ERUS is easy to learn and more accurate in early stages but unnecessary for restaging after CRT. Staging accuracy is similar in Western and Central Europe, although the number of examinations should be increased.

The accuracy of endorectal ultrasonography in rectal cancer staging

Background and aims

The incidence of rectal cancer in the European Union is about 35% of the total colorectal cancer incidence. Staging rectal cancer is important for planning treatment. It is essential for the management of rectal cancer to have adequate preoperative imaging, because accurate staging can influence the therapeutic strategy, type of resection, and candidacy for neoadjuvant therapy. The aim of this work is to evaluate the accuracy of endorectal ultrasound (ERUS) in rectal cancer staging.

Methods

A retrospective study was performed to assess the accuracy of ERUS by analyzing patients discharged from Regional Institute of Gastroenterology and Hepatology (IRGH) Cluj-Napoca, Romania, diagnosed with rectal cancer between 01 January 2011 and 31 December 2013. Patients who were preoperatively staged by other imaging methods and those who had ERUS performed in another service were excluded from the analysis. As inclusion criteria remained ERUS performed for patients with rectal cancer in IRGH Cluj-Napoca where they were also operated. We analyzed preoperative T stage obtained by ERUS and it was compared with the histopathology findings.

Results

The number of patients discharged with a diagnosis of rectal cancer were 200 (operated – 157) in 2011, 193 (operated – 151) in 2012, and 198 (operated – 142) in 2013. We analyzed a total of 51 cases diagnosed with rectal cancer who performed ERUS in IRGH Cluj-Napoca. The results according to the T stage obtained by ERUS and histopathology test were:

Conclusions

ERUS is a method of staging rectal cancer which is human dependent. ERUS is less accurate for T staging of stenotic tumours, but the accuracy may still be within acceptable limits. Surgeons use ERUS to adopt a treatment protocol, knowing the risk of under-staging and over-staging of this method. The accuracy of ERUS is higher in diagnosing rectal cancer in stages T1, T2 and even in stage T3 with malignant tumor which is not occlusive. ERUS is less accurate for T staging of locally advanced and stenotic tumours.

Utility of EUS following endoscopic polypectomy of high-risk rectosigmoid lesions

Background:

The utility of endoscopic ultrasound (EUS) compared with standard white light endoscopy (WLE) following recent polypectomy of high-risk colorectal polyps is unknown.

Objective:

To assess the incremental yield of EUS after endoscopic polypectomy of a high-risk rectal lesion.

Design:

Retrospective cohort.

Setting:

Tertiary referral center.

Materials and Methods:

Patients referred for EUS following attempted endoscopic resection of a high-risk rectal neoplasm, defined as a tubulovillous adenoma, tubular adenoma with high-grade dysplasia, carcinoid, carcinoma in-situ or adenocarcinoma (CA).

Interventions:

Sigmoidoscopy ± mucosal biopsy and EUS ± fine-needle aspiration (FNA) to evaluate for: (1) Residual polyp/tumor in the rectal wall or (2) peritumoral adenopathy.

Main Outcome:

Sensitivity and specificity for detection of residual neoplasia for WLE ± biopsy (WLE/BX) and EUS ± FNA for cancer (CA group) or benign disease (non-CA group). The incremental yield of EUS defined as: (1) Residual intramural neoplasia not present on WLE ± BX and; (2) abnormal peritumoral adenopathy.

Results:

A total of 70 patients (mean age 64 ± 11 years, 61% male) with a final diagnosis of CA (n = 38) and non-CA (n = 32) were identified. There was no difference between the sensitivity and specificity of WLE alone (65% and 84%), WLE with biopsy (71% and 95%), and EUS (59% and 84%), for the detection of residual neoplasia (P > 0.05 for all). EUS identified 3 masses missed by WLE, all in the CA group. A malignant (n = 2) or benign (n = 3) node was identified in 5 (13%) CA patients; EUS-FNA in two showed residual malignancy in one and a reactive lymph node (LN) in one. No LNs were identified in the non-CA patients.

Limitations:

Retrospective design, incomplete follow-up in some patients.

Conclusion:

Following endoscopic polypectomy of high-risk rectal neoplasia, the incremental yield of EUS compared with WLE/BX for evaluation of residual disease appears limited, especially in patients with benign disease.

Clinical results and toxicity for short-course preoperative radiotherapy and total mesorectal excision in rectal cancer patients

Short-course preoperative radiotherapy (SCPRT) is an alternative method to chemoirradiation for patients with Stage II and III rectal cancer when no downsizing is needed, but there is still widespread reluctance to use this method because of fear of side effects from high-fraction doses. This paper reports on a single institution patient cohort of operated rectal cancer patients after SCPRT, evaluated for chronic adverse effects, local control, progression-free survival and overall survival. Altogether, 257 patients were treated with SCPRT and surgery including total mesorectal excision (92% total mesorectal excision = TME) between 2002 and 2009. Local control and survival were analyzed. Chronic adverse effects for 154 patients without local relapse were evaluated according to the NCI-CTCAE version 4.0 classification, with a median follow-up of 48 months. We found a 5-year disease-free survival (DFS) and overall survival (OS) of 71%. The 5-year estimated local control (LC) rate was 94%. A positive resection margin was found in 4% of the patients and was significantly correlated with decreased DFS, OS and LC. Chronic adverse effects were reported by 58% of the patients, of which 10% were Grade 3 toxicities. The most frequent Grade 2 toxicity was stool incontinence (13%). Sexual dysfunction was found in 36% of the patients (31% Grade 1 or 2, and only 5% Grade 3). SCPRT combined with TME produced excellent LC rates together with a low rate of high-grade chronic adverse effects.

Transrectal ultrasonography of anorectal diseases: advantages and disadvantages

Transrectal ultrasonography (TRUS) has been widely accepted as a popular imaging modality for evaluating the lower rectum, anal sphincters, and pelvic floor in patients with various anorectal diseases. It provides excellent visualization of the layers of the rectal wall and of the anatomy of the anal canal. TRUS is an accurate tool for the staging of primary rectal cancer, especially for early stages. Although magnetic resonance imaging is a modality complementary to TRUS with advantages for evaluating the mesorectum, external sphincter, and deep pelvic inflammation, three-dimensional ultrasonography improves the detection and characterization of perianal fistulas and therefore plays a crucial role in optimal treatment planning. The operator should be familiar with the anatomy of the rectum and pelvic structures relevant to the preoperative evaluation of rectal cancer and other anal canal diseases, and should have technical proficiency in the use of TRUS combined with an awareness of its limitations compared to magnetic resonance imaging.

Learning curve of endorectal ultrasonography in preoperative staging of rectal carcinoma

Accurate preoperative staging of rectal carcinoma is essential for optimal treatment. This study was designed to evaluate the accuracy and learning curve of endorectal ultrasonography (ERUS) in the preoperative staging of rectal carcinoma. We retrospectively analyzed the records of patients with rectal carcinoma who underwent preoperative ERUS followed by curative surgery at the Shanxi Province Tumor Hospital between January, 2007 and March, 2010. The patients were divided into three groups, namely A, B and C, depending on whether the examination was performed between January and December, 2007, between January and December, 2008 or between January, 2009 and March, 2010, respectively. Five physicians with no prior experience in ERUS performed the examinations. We compared the ERUS staging with the pathological findings using the tumor-node-metastasis (TNM) classification. The accuracy of ERUS in T and N staging after each additional consecutive 20 patients was calculated for physicians D, E and F. A total of 319 patients underwent ERUS prior to surgery. There were 38 patients in group A, 135 in group B and 146 in group C. Two of the five physicians performed only 47 of the 319 examinations, whereas the remaining 272 patients were examined by physicians D (n=162), E (n=64) and F (n=46). The overall accuracy in assessing the extent of rectal wall invasion (T) was 67%, with 16% of the cases overstaged and 17% understaged and the accuracy in assessing nodal involvement (N) was 66%, with 11% of the cases overstaged and 23% understaged. The total T and N staging accuracy of physicians D, E and F was 75 and 72%; 59 and 59%; and 50 and 52%, respectively. For physicians D, E and F, the accuracy of T and N staging after each additional 20 patients was calculated and the curve of the accuracy reached a plateau after physician D completed 80 cases. Therefore, ERUS is a valuable tool for assessing the depth of tumor invasion and it appears that after ~80 cases a physician may be considered able to apply it efficiently.

The role of endoscopic ultrasound in the diagnosis and therapy of gastrointestinal disorders

Endoscopic ultrasound is one of those diagnostic methods in gastrointestinal endoscopy which has developed rapidly in the last decade and has became exceedingly available to visualize the walls of the internal organs in details corresponding to histological layers, or analyze the adjacent structures. Fine needles and other endoscopic accessories can be introduced into the neighbouring tissues under the guidance of endoscopic ultrasound, and diagnostic and minimally invasive therapeutic interventions can be performed. The endoscopic ultrasound became more widely available in Hungary in the recent years. This review focuses on the indications, benefits and complications of diagnostic and therapeutic endoscopic ultrasound. We dedicate this article for gastroenterologists, surgeons, internists, pulmonologists, specialists in oncology and radiology. This recommendation was based on the consensus of the Board members of the Endoscopic Ultrasound Section of the Hungarian Gastroenterological Society. Orv. Hetil., 2014, 155(14), 526–540.

Forward-viewing radial-array echoendoscope for staging of colon cancer beyond the rectum

AIM: To evaluate feasibility of the novel forward-viewing radial-array echoendoscope for staging of colon cancer beyond rectum as the first series.

METHODS: A retrospective study with prospectively entered database. From March 2012 to February 2013, a total of 21 patients (11 men) (mean age 64.2 years) with colon cancer beyond the rectum were recruited. The novel forward-viewing radial-array echoendoscope was used for ultrasonographic staging of colon cancer beyond rectum. Ultrasonographic T and N staging were recorded when surgical pathology was used as a gold standard.

RESULTS: The mean time to reach the lesion and the mean time to complete the procedure were 3.5 and 7.1 min, respectively. The echoendoscope passed through the lesions in 13 patients (61.9%) and reached the cecum in 10 of 13 patients (76.9%). No adverse events were found. The lesions were located in the cecum (n = 2), ascending colon (n = 1), transverse colon (n = 2), descending colon (n = 2), and sigmoid colon (n = 14). The accuracy rate for T1 (n = 3), T2 (n = 4), T3 (n = 13) and T4 (n = 1) were 100%, 60.0%, 84.6% and 100%, respectively. The overall accuracy rates for the T and N staging of colon cancer were 81.0% and 52.4%, respectively. The accuracy rates among traversable lesions (n = 13) and obstructive lesions (n = 8) were 61.5% and 100%, respectively. Endoscopic ultrasound and computed tomography had overall accuracy rates of 81.0% and 68.4%, respectively.

CONCLUSION: The echoendoscope is a feasible staging tool for colon cancer beyond rectum. However, accuracy of the echoendoscope needs to be verified by larger systematic studies.

Imaging assessment of early rectal cancer

Early rectal cancer (ERC) is defined as invasive adenocarcinoma spreading into, but not beyond, the submucosa or muscularis propria-that is a Dukes'A: T1N0 or T2N0 tumour in the tumour node metastasis (TNM) classification (Taylor et al. 2008). Among these tumours it is suggested that the most superficial T1 tumours least likely to metastasize to local lymph nodes than adenocarcinoma invading deeper where the rich lymphatic and venous plexuses within the submucosa provide a mechanism for tumour spread beyond the rectum. Currently, only about 10 % of patients presenting symptomatically with rectal cancer are diagnosed with early disease; however, up to 30 % of screen detected cancers are being identified as Dukes'A. Thus, the overall detection of early stage tumours is likely to increase following greater implementation in screening programs. The goal of this invited review is to provide recommendations based on the consensus discussion on the information from preoperative imaging that is of relevance for clinical decision-making for patients with early rectal cancer.

Current approaches and challenges for monitoring treatment response in colon and rectal cancer

Introduction: With the advent of multidisciplinary and multimodality approaches to the management of colorectal cancer patients, there is an increasing need to define how we monitor response to novel therapies in these patients. Several factors ranging from the type of therapy used to the intrinsic biology of the tumor play a role in tumor response. All of these can aid in determining the ideal course of treatment, and may fluctuate over time, pending down-staging or progression of disease. Therefore, monitoring how disease responds to therapy requires standardization in order to ultimately optimize patient outcomes. Unfortunately, how best to do this remains a topic of debate among oncologists, pathologists, and colorectal surgeons. There may not be one single best approach. The goal of the present article is to shed some light on current approaches and challenges to monitoring treatment response for colorectal cancer.

Methods: A literature search was conducted utilizing PubMed and the OVID library. Key-word combinations included colorectal cancer metastases, neoadjuvant therapy, rectal cancer, imaging modalities, CEA, down-staging, tumor response, and biomarkers. Directed searches of the embedded references from the primary articles were also performed in selected circumstances.

Results: Pathologic examination of the post-treatment surgical specimen is the gold standard for monitoring response to therapy. Endoscopy is useful for evaluating local recurrence, but not in assessing tumor response outside of the limited information gained by direct examination of intra-lumenal lesions. Imaging is used to monitor tumors throughout the body for response, with CT, PET, and MRI employed in different circumstances. Overall, each has been validated in the monitoring of patients with colorectal cancer and residual tumors.

Conclusion: Although there is no imaging or serum test to precisely correlate with a tumor's response to chemo- or radiation therapy, these modalities, when used in combination, can aid in allowing clinicians to adjust medical therapy, pursue operative intervention, or (in select cases) identify complete responders. Improvements are needed, however, as advances across multiple modalities could allow appropriate selection of patients for a close surveillance regimen in the absence of operative intervention.

[The role of endoscopic ultrasonography in the diagnosis of rectal cancers]

INTRODUCTION

The exact extent of rectal cancer and regional lymph node involvement are essential for providing the optimal treatment.

AIM

The aim of the authors was to evaluate the diagnostic accuracy of endoscopic ultrasonography in routine clinical staging of rectal cancer.

METHOD

Outcomes of endoscopic ultrasonography performed between 2006 and 2012 for rectal cancer staging were retrospectively analyzed. The correlation between the endoscopic and pathological stages was evaluated.

RESULTS

In patients without neoadjuvant chemotherapy the sensitivity (75% and 73%) and specificity (74% and 80%) of endoscopic ultrasonography for differentiating T1 and T2 stages (respectively) were high, however, it was significantly decreased in differentiation of T3 stage (58%). A weak association was found in different N stages (45-62%). The diagnostic accuracy of endoscopic ultrasound was reduced significantly after the oncological treatment due to the overevaluation (27%) of the findings. After a relatively short learning curve (30 examinations) high correlation was detected between pT and uT stages.

CONCLUSIONS

Endoscopic ultrasonography provides great help in staging early rectal cancers. Due to the lower sensitivity in patients receiving neoadjuvant therapy, it is not a useful tool after down-staging.

Transrectal ultrasound and magnetic resonance imaging measurement of extramural tumor spread in rectal cancer

AIM: To evaluate the agreement between transrectal ultrasound (TRUS) and magnetic resonance imaging (MRI) in classification of ≥ T3 rectal tumors.

METHODS: From January 2010 to January 2012, 86 consecutive patients with ≥ T3 tumors were included in this study. The mean age of the patients was 66.4 years (range: 26-91 years). The tumors were all ≥ T3 on TRUS. The sub-classification was defined by the penetration of the rectal wall: a: 0 to 1 mm; b: 1-5 mm; c: 6-15; d: > 15 mm. Early tumors as ab (≤ 5 mm) and advanced tumors as cd (> 5 mm). All patients underwent TRUS using a 6.5 MHz transrectal transducer. The MRI was performed with a 1.5 T Philips unit. The TRUS findings were blinded to the radiologist performing the interpretation of the MRI images and measuring the depth of extramural tumor spread.

RESULTS: TRUS found 51 patients to have an early ≥ T3 tumors and 35 to have an advanced tumor, whereas MRI categorized 48 as early ≥ T3 tumors and 38 as advanced tumors. No patients with tumors classified as advanced by TRUS were found to be early on MRI. The kappa value in classifying early versus advanced T3 rectal tumors was 0.93 (95% CI: 0.85-1.00). We found a kappa value of 0.74 (95% CI: 0.63-0.86) for the total sub-classification between the two methods. The mean maximal tumor outgrowth measured by TRUS, 5.5 mm ± 5.63 mm and on MRI, 6.3 mm ± 6.18 mm, P = 0.004. In 19 of the 86 patients the following CT scan or surgery revealed distant metastases; of the 51 patients in the ultrasound ab group three (5.9%) had metastases, whereas 16 (45.7%) of 35 in the cd group harbored distant metastases, P = 0.00002. The odds ratio of having distant metastases in the ultrasound cd group compared to the ab group was 13.5 (95% CI: 3.5-51.6), P = 0.00002. The mean maximal ultrasound measured outgrowth was 4.3 mm (95% CI: 3.2-5.5 mm) in patients without distant metastases, while the mean maximal outgrowth was 9.5 mm (95% CI: 6.2-12.8 mm) in the patients with metastases, P = 0.00004. Using the MRI classification three (6.3%) of 48 in the MRI ab group had distant metastases, while 16 (42.1%) of the 38 in the MRI cd group, P = 0.00004. The MRI odds ratio was 10.9 (95% CI: 2.9-41.4), P = 0.00008. The mean maximal MRI measured outgrowth was 4.9 mm (95% CI: 3.7-6.1 mm) in patients without distant metastases, while the mean maximal outgrowth was 11.5 mm (95% CI: 7.8-15.2 mm) in the patients with metastases, P = 0.000006.

CONCLUSION: There is good agreement between TRUS and MRI in the pretreatment sub-classification of ≥ T3 tumors. Distant metastases are more frequent in the advanced group.

Improvement in T-staging of rectal carcinoma: using a novel endorectal ultrasonography technique with sterile coupling gel filling the rectum

Our purpose was to study the accuracy of using endorectal ultrasonography (ERUS) with sterile coupling gels filling the rectum in the preoperative T-staging of rectal carcinoma. A total of 189 patients with confirmed rectal carcinoma were recruited. All underwent ERUS and surgery within the week following sonography. EURS was performed by introducing sterile coupling gel into the rectum. Two radiologists looked at the images at the same time and agreed upon staging. Rectal carcinoma was staged from Tis to T4. The accuracy of T-staging by ERUS was 89.95%. The sensitivity, specificity, PPV and NPV for ERUS at different stages were calculated. For early stage (Tis and T1), these values were 93.62%, 97.89%, 93.62% and 97.89%, respectively. ERUS filling with sterile coupling gel in the rectum overcomes the pressure effect from a water bath and the restriction caused by tumor stenosis, thus, greatly improving the accuracy of T-staging. The examination is real-time, safe and inexpensive.

Preoperative radiation therapy for upper rectal cancer T3,T4/Nx: selectivity essential

This review explores the current available literature regarding the role of neoadjuvant therapy for upper locally advanced rectal cancers (≥10 cm-15 cm). Although there is a paucity of data evaluating the outcomes of preoperative chemoradiation for upper rectal cancers the authors suggest that T3N0 tumors will not likely benefit from radiation and that treatment of T4N0 should be individualized.

Linear array ultrasonography to stage rectal neoplasias suitable for local treatment

BACKGROUND

Because of the many therapeutic options available, a reliable staging is crucial for rectal neoplasia management. Adenomas and cancers limited to the submucosa without lymph node involvement may be treated locally.

AIMS

The aim of this study is to evaluate the diagnostic accuracy of endorectal ultrasonography in the staging of neoplasias suitable for local treatment.

METHODS

We considered all patients who underwent endorectal ultrasonography between 2001 and 2010. The study population consisted of 92 patients with 92 neoplasias (68 adenocarcinomas and 24 adenomas). A 5 and 7.5MHz linear array echoendoscope was used. The postoperative histopathologic result was compared with the preoperative staging defined by endorectal ultrasonography. Adenomas and cancers limited to the submucosa were considered together (pT0-1).

RESULTS

The sensitivity, specificity, overall accuracy rate, positive predictive value, and negative predictive value of endorectal ultrasonography for pT0-1 were 86%, 95.6%, 91.3%, 94.9% and 88.7%. Those for nodal involvement were 45.4%, 95.5%, 83%, 76.9% and 84%, with 3 false positive results and 12 false negative. For combined pT0-1 and pN0, endorectal ultrasonography showed an 87.5% sensitivity, 95.9% specificity, 92% overall accuracy rate, 94.9% positive predictive value and 90.2% negative predictive value.

CONCLUSION

Endorectal linear array ultrasonography is a reliable tool to detect rectal neoplasias suitable for local treatment.