The learning curve for endorectal ultrasonography in rectal cancer staging

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.

ACR Appropriateness Criteria® Staging of Colorectal Cancer: 2021 Update

Preoperative imaging of rectal carcinoma involves accurate assessment of the primary tumor as well as distant metastatic disease. Preoperative imaging of nonrectal colon cancer is most beneficial in identifying distant metastases, regardless of primary T or N stage. Surgical treatment remains the definitive treatment for colon cancer, while organ-sparing approach may be considered in some rectal cancer patients based on imaging obtained before and after neoadjuvant treatment. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Pretreatment Staging of Colorectal Cancer

Colorectal cancers are common tumors in the United States and appropriate imaging is essential to direct appropriate care. Staging and treatment differs between tumors arising in the colon versus the rectum. Local staging for colon cancer is less integral to directing therapy given radical resection is often standard. Surgical options for rectal carcinoma are more varied and rely on accurate assessment of the sphincter, circumferential resection margins, and peritoneal reflection. These important anatomic landmarks are best appreciated on high-resolution imaging with transrectal ultrasound or MRI. When metastatic disease is suspected, imaging modalities that provide a global view of the body, such as CT with contrast or PET/CT may be indicated. Rectal cancer often metastasizes to the liver and so MRI of the liver with and without contrast provides accurate staging for liver metastases. This article focuses on local and distant staging and reviews the appropriateness of different imaging for both variants. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Beyond Histologic Staging: Emerging Imaging Strategies in Colorectal Cancer with Special Focus on Magnetic Resonance Imaging

Imaging plays an increasingly important role in the staging and management of colorectal cancer. In recent years, magnetic resonance imaging (MRI) has supplanted transrectal ultrasound as the preferred modality for the locoregional staging of rectal cancer. Furthermore, the advent of both diffusion-weighted imaging and hepatobiliary contrast agents has significantly enhanced the ability of MRI to detect colorectal liver metastases. In clinical practice, MRI routinely provides prognostic information, helps to guide surgical strategy, and determines the need for neoadjuvant therapies related to both the primary tumor and metastatic disease. Expanding on these roles for MRI, positron emission tomography (PET)/MRI is the newest clinical hybrid imaging modality and combines the metabolic information of PET with the high soft tissue contrast of MRI. The addition of PET/MRI to the clinical staging armamentarium has the potential to provide comprehensive state-of-the-art colorectal cancer staging in a single examination.

Measures of trainee performance in advanced endoscopy: A systematic review

INTRODUCTION

The diversity, technical skills required, and risk inherent to advanced endoscopy techniques all contribute to complex training curricula and steep learning curves. Since trainees develop endoscopy skills at different rates, there has been a shift towards competency-based training and certification. Validated endoscopy performance measures for trainees are, therefore, necessary. The aim of this systematic review was to describe and critically assess the existing evidence regarding measures of performance for trainees in advanced endoscopy.

METHODS

A systematic review of the literature from January 1980 to January 2016 was carried out using the MEDLINE, EMBASE, CENTRAL, and ISI Web of knowledge databases. MeSH terms related to 'advanced endoscopy' and 'performance' were applied to a highly sensitive search strategy. The main outcomes were face, content, and construct validity, as well as reliability.

RESULTS

The literature search yielded 1,662 studies and 77 met the inclusion criteria after abstract and full-text review (endoscopic retrograde cholangiopancreatography (ERCP)=23, endoscopic ultrasound (EUS)=30, colonoscopic polypectomy (CP)=11, balloon-assisted enteroscopy (BAE)=7, luminal stenting=3, radiofrequency ablation (RFA)=2, and endoscopic muscosal resection (EMR)=1). Good validity and reliability were found for measurement tools of overall performance in ERCP, EUS and CP, with applications for both patient-based and simulator training models. A number of specific technical skills were also shown to be valid measures of performance. These include: selective biliary cannulation, sphincterotomy, biliary stent placement, stone extraction and procedure time for ERCP; pancreatic solid mass T-staging, EUS-guided fine needle aspiration (EUS-FNA) procedure time, number of EUS-FNA passes and puncture precision for EUS; procedure time and en bloc resection rate for CP; retrograde fluoroscopy time for BAE; and mean number of endoscopy sessions required to achieve complete eradication of intestinal metaplasia (CIEM) for RFA. The evidence for EMR and luminal stenting is of insufficient quality to make recommendations.

CONCLUSIONS

We have identified multiple valid and readily available performance measures for advanced endoscopy trainees for ERCP, EUS, CP, BAE and RFA procedures. These tools should be considered in advanced endoscopy training programs wishing to move away from apprenticeship-based training and towards competency-based learning with the help of patient-based and simulator tools.

Diagnostic Value of Endorectal Ultrasound in Preoperative Assessment of Lymph Node Involvement in Colorectal Cancer: a Meta-analysis

BACKGROUND

Nodal invasion by colorectal cancer is a critical determinant in estimating patient survival and in choosing appropriate preoperative treatment. The present meta-analysis was designed to evaluate the diagnostic value of endorectal ultrasound (EUS) in preoperative assessment of lymph node involvement in colorectal cancer.

MATERIALS AND METHODS

We systematically searched PubMed, Web of Science, Embase, and China National Knowledge Infrastructure (CNKI) databases for relevant studies published on or before December 10th, 2014. The sensitivity, specificity, likelihood ratios, diagnostic odds ratio (DOR) and area under the summary receiver operating characteristics curve (AUC) were assessed to estimate the diagnostic value of EUS. Subgroup analysis and meta-regression were performed to explore heterogeneity across studies.

RESULTS

Thirty-three studies covering 3,016 subjects were included. The pooled sensitivity and specificity were 0.69 (95%CI: 0.63-0.75) and 0.77 (95%CI: 0.73-0.82), respectively. The positive and negative likelihood ratios were 3.09 (95%CI: 2.52-3.78) and 0.39 (95%CI: 0.32-0.48), respectively. The DOR was 7.84 (95%CI: 5.56-11.08), and AUC was 0.80 (95%CI: 0.77-0.84).

CONCLUSIONS

This meta-analysis indicated that EUS has moderate diagnostic value in preoperative assessment of lymph node involvement in colorectal cancer. Further refinements in technology and diagnostic criteria are necessary to improve the diagnostic accuracy of EUS.

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.

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.

[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.