• Humans
• Neoplasms
• Immunotherapy

• Humans
• Neoadjuvant Therapy
• Immune Checkpoint Inhibitors/therapeutic use
• Organ Preservation
• Neoplasm Staging
• Precision Medicine
• Colorectal Neoplasms/pathology
• Retrospective Studies
• Rectal Neoplasms/surgery
• DNA Mismatch Repair

Magnetic resonance imaging (MRI)-based lymph node staging remains a significant challenge in the treatment of rectal cancer. Pretreatment evaluation of lymph node metastasis guides the formulation of treatment plans. This systematic review aimed to evaluate the diagnostic performance of MRI in lymph node staging using various morphological criteria.

A systematic search of the EMBASE, Medline, and Cochrane databases was performed. Original articles published between 2000 and January 2021 that used MRI for lymph node staging in rectal cancer were eligible. The included studies were assessed using the QUADAS-2 tool. A bivariate random-effects model was used to conduct a meta-analysis of diagnostic test accuracy.

Thirty-seven studies were eligible for this meta-analysis. The pooled sensitivity, specificity, and diagnostic odds ratio of preoperative MRI for the lymph node stage were 0.73 (95% confidence interval [CI], 0.68–0.77), 0.74 (95% CI, 0.68–0.80), and 7.85 (95% CI, 5.78–10.66), respectively. Criteria for positive mesorectal lymph node metastasis included (A) a short-axis diameter of 5 mm, (B) morphological standard, including an irregular border and mixed-signal intensity within the lymph node, (C) a short-axis diameter of 5 mm with the morphological standard, (D) a short-axis diameter of 8 mm with the morphological standard, and (E) a short-axis diameter of 10 mm with the morphological standard. The pooled sensitivity/specificity for these criteria were 75%/64%, 81%/67%, 74%/79%, 72%/66%, and 62%/91%, respectively. There was no significant difference among the criteria in sensitivity/specificity. The area under the receiver operating characteristic (ROC) curve values of the fitted summary ROC indicated a diagnostic accuracy rate of 0.75–0.81.

MRI scans have minimal accuracy as a reference index for pretreatment staging of various lymph node staging criteria in rectal cancer. Multiple types of evidence should be used in clinical decision-making.

• lymph node
• lymph node staging
• magnetic resonance imaging
• metastasis
• node-by-node
• rectal cancer

• Endoscopic ultrasound
• Preoperative staging
• Transanal Endoscopic Microsurgery

• Beyond TME
• CRM
• EMVI
• Early rectal cancer
• Extramural spread
• Imaging biomarkers
• Low rectal cancer
• MR-defined surgical planes
• Mucinous tumours
• Rectal cancer
• Staging
• TRG

The prognosis of rectal cancer (RC) is strictly related to both T and N stage of the disease at the time of diagnosis. RC staging is crucial for choosing the best multimodal therapy: patients with high risk locally advanced RC (LARC) undergo surgery after neoadjuvant chemotherapy and radiotherapy (NAT); those with low risk LARC are operated on after a preoperative short-course radiation therapy; finally, surgery alone is recommended only for early RC. Several imaging methods are used for staging patients with RC: computerized tomography, magnetic resonance imaging, positron emission tomography, and endoscopic ultrasound (EUS). EUS is highly accurate for the loco-regional staging of RC, since it is capable to evaluate precisely the mural infiltration of the tumor (T), especially in early RC. On the other hand, EUS is less accurate in restaging RC after NAT and before surgery. Finally, EUS is indicated for follow-up of patients operated on for RC, where there is a need for the surveillance of the anastomosis. The aim of this review is to highlight the impact of EUS on the management of patients with RC, evaluating its role in both preoperative staging and follow-up of patients after surgery.

• Rectal cancer
• Staging
• Endoscopic ultrasonography
• Accuracy
• Therapeutic strategy

• Colorectal Cancer
• Diagnosis
• Locoregional Invasion
• Neoadjuvant Therapy

• MRI
• Rectal cancer
• prognostic factors
• tailored treatment

AIM: To assess the stage and size of rectal tumours using 1.5 Tesla (1.5T) magnetic resonance imaging (MRI) and three-dimensional (3D) endosonography (ERUS).

METHODS: In this study, patients were recruited in a phase I/II trial of neoadjuvant chemotherapy for biopsy-proven rectal cancer planned for surgical resection with or without preoperative radiotherapy. The feasibility and accuracy of 1.5T MRI and 3D ERUS were compared with the histopathology of the fixed surgical specimen (pathology) to determine the stage and size of the rectal cancer before and after neoadjuvant chemotherapy. A Philips Intera 1.5T with a cardiac 5-channel synergy surface coil was used for the MRI, and a B-K Medical Falcon 2101 EXL 3D-Probe was used at 13 MHz for the ERUS. Our hypothesis was that the staging accuracy would be the same when using MRI, ERUS and a combination of MRI and ERUS. For the combination, MRI was chosen for the assessment of the lymph nodes, and ERUS was chosen for the assessment of perirectal tissue penetration. The stage was dichotomised into stage I and stage II or greater. The size was measured as the supero-inferior length and the maximal transaxial area of the tumour.

RESULTS: The staging feasibility was 37 of 37 for the MRI and 29 of 36 for the ERUS, with stenosis as a limiting factor. Complete sets of investigations were available in 18 patients for size and 23 patients for stage. The stage accuracy by MRI, ERUS and the combination of MRI and ERUS was 0.65, 0.70 and 0.74, respectively, before chemotherapy and 0.65, 0.78 and 0.83, respectively, after chemotherapy. The improvement of the post-chemotherapy staging using the combination of MRI and ERUS compared with the staging using MRI alone was significant (P = 0.046). The post-chemotherapy understaging frequency by MRI, ERUS and the combination of MRI and ERUS was 0.18, 0.14 and 0.045, respectively, and these differences were non-significant. The measurements of the supero-inferior length by ERUS compared with MRI were within 1.96 standard deviations of the difference between the methods (18 mm) for tumours smaller than 50 mm. The agreement with pathology was within 1.96 standard deviations of the difference between imaging and pathology for all tumours with MRI (15 mm) and for tumours that did not exceed 50 mm with ERUS (22 mm). Tumours exceeding 50 mm in length could not be reliably measured by ERUS due to the limit in the length of each recording.

CONCLUSION: MRI is preferable to use when assessing the size of large or stenotic rectal tumours. However, staging accuracy is improved by combining MRI with ERUS.

• Rectal cancer
• Magnetic resonance imaging
• Endosonography
• Predictive value of tests
• Neoadjuvant treatment

• Aged
• Biopsy
• Endosonography
• Feasibility Studies
• Female
• Humans
• Magnetic Resonance Imaging
• Male
• Middle Aged
• Multimodal Imaging
• Neoadjuvant Therapy
• Neoplasm Staging/methods
• Predictive Value of Tests
• Prospective Studies
• Radiotherapy, Adjuvant
• Rectal Neoplasms/diagnosis
• Rectal Neoplasms/diagnostic imaging
• Rectal Neoplasms/pathology
• Rectal Neoplasms/therapy
• Sweden
• Treatment Outcome
• Tumor Burden

• cancer staging
• cancer
• endoscopic ultrasound
• multi-detector row computerized tomography
• rectal

AIM: To evaluate the use of endoscopic ultrasonography (EUS) in the staging and treatment of colorectal carcinoma.

METHODS: Fifty-six patients who were diagnosed with colorectal cancer by endoscopic biopsy in our department underwent EUS staging (TN). According to the results of EUS staging, the patients were treated with surgery. After postoperative pathologic staging, the patients with stage 2 and stage 3 disease were given adjuvant chemotherapy. Using postoperative pathology as a gold standard, the accuracy of EUS staging was calculated. The patients were followed for over two years and the rate of recurrence was calculated.

RESULTS: The accuracy rates of uT staging for colorectal cancer were 88.89% (T1), 83.33% (T2), 85.71% (T3), and 75.00% (T4), and the total accuracy rate of uT staging for colorectal cancer is 83.23%. The accuracy rates of uN staging were 81.25% (uN(+)) and 80% (uN(-)), and the total accuracy rate of uN staging is 80.63%. Six (10.71%) patients had recurrence.

CONCLUSION: EUS is useful for the staging and treatment of colorectal cancer.

• Endoscopic ultrasonography
• TNM staging
• Colorectal cancer

• Adult
• Aged
• Aged, 80 and over
• Endosonography/methods
• Female
• Gels
• Humans
• Male
• Middle Aged
• Neoplasm Invasiveness
• Neoplasm Staging
• Predictive Value of Tests
• Rectal Neoplasms/diagnostic imaging
• Rectal Neoplasms/pathology
• Rectal Neoplasms/surgery
• Sensitivity and Specificity

• Adenocarcinoma/complications
• Adenocarcinoma/diagnosis
• Adenocarcinoma/diagnostic imaging
• Biopsy
• Child
• Gastrointestinal Hemorrhage/etiology
• Humans
• Magnetic Resonance Imaging
• Male
• Neurofibromatosis 1/complications
• Neurofibromatosis 1/diagnosis
• Radiography, Abdominal
• Rectal Neoplasms/complications
• Rectal Neoplasms/diagnosis
• Rectal Neoplasms/diagnostic imaging
• Rectum
• Recurrence
• Time Factors
• Tomography, X-Ray Computed

It is essential in treating rectal cancer to have adequate preoperative imaging, as accurate staging can influence the management strategy, type of resection, and candidacy for neoadjuvant therapy. In the last twenty years, endorectal ultrasound (ERUS) has become the primary method for locoregional staging of rectal cancer. ERUS is the most accurate modality for assessing local depth of invasion of rectal carcinoma into the rectal wall layers (T stage). Lower accuracy for T2 tumors is commonly reported, which could lead to sonographic overstaging of T3 tumors following preoperative therapy. Unfortunately, ERUS is not as good for predicting nodal metastases as it is for tumor depth, which could be related to the unclear definition of nodal metastases. The use of multiple criteria might improve accuracy. Failure to evaluate nodal status could lead to inadequate surgical resection. ERUS can accurately distinguish early cancers from advanced ones, with a high detection rate of residual carcinoma in the rectal wall. ERUS is also useful for detection of local recurrence at the anastomosis site, which might require fine-needle aspiration of the tissue. Overstaging is more frequent than understaging, mostly due to inflammatory changes. Limitations of ERUS are operator and experience dependency, limited tolerance of patients, and limited range of depth of the transducer. The ERUS technique requires a learning curve for orientation and identification of images and planes. With sufficient time and effort, quality and accuracy of the ERUS procedure could be improved.

• Rectal cancer
• Colorectal cancer
• Staging
• Endorectal ultrasonography
• Endorectal ultrasound
• Accuracy
• Tumor invasion
• Nodal metastases
• Other rectal tumors
• Diagnostics

AIM: To compare the sensitivity and specificity of two imaging techniques, endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI), in patients with rectal cancer after neoadjuvant chemoradiation therapy. And we compared EUS and MRI data with histological findings from surgical specimens.

METHODS: Thirty-nine consecutive patients (51.3% Male; mean age: 68.2 ± 8.9 years) with histologically confirmed distal rectal cancer were examined for staging. All patients underwent EUS and MRI imaging before and after neoadjuvant chemoradiation therapy.

RESULTS: After neoadjuvant chemoradiation, EUS and MRI correctly classified 46% (18/39) and 44% (17/39) of patients, respectively, in line with their histological T stage (P > 0.05). These proportions were higher for both techniques when nodal involvement was considered: 69% (27/39) and 62% (24/39). When patients were sorted into T and N subgroups, the diagnostic accuracy of EUS was better than MRI for patients with T0-T2 (44% vs 33%, P > 0.05) and N0 disease (87% vs 52%, P = 0.013). However, MRI was more accurate than EUS in T and N staging for patients with more advanced disease after radiotherapy, though these differences did not reach statistical significance.

CONCLUSION: EUS and MRI are accurate imaging techniques for staging rectal cancer. However, after neoadjuvant RT-CT, the role of both methods in the assessment of residual rectal tumors remains uncertain.

• Endoscopic ultrasound
• Magnetic resonance imaging
• Rectal cancer
• Neoadjuvant chemoradiation therapy
• Diagnostic accuracy

• Colonography, Computed Tomographic
• Colorectal Neoplasms/diagnosis
• Humans
• Magnetic Resonance Imaging
• Positron-Emission Tomography
• Tomography, X-Ray Computed