Preoperative Staging Of Rectal Cancer Research Articles

MRI in rectal cancer: An institutional real life analysis of technical parameters

MRI plays a key role in the preoperative staging of rectal cancers and choice of neoadjuvant radiochemotherapy. Yet, the acquisition and interpretation of rectum magnetic resonance imaging (MRI) turn out to be unequal, impacting patients'care. The present study aims at evaluating the quality of the acquisition of technical parameters of the rectal MRI performed by comparing them according to the various guidelines. The medical MRI reports of all consecutive patients with locally advanced rectal cancer treated in a curative intent, by preoperative RCT and completion surgery were retrospectively reviewed over two periods (January 2010-December 2014 and January 2018 and December 2020) according to international 2012 and 2016 ESGAR and 2017 SAR MRI recommendation reports. During the first period (69 MRI performed), 58% of these MRI abided by the recommendations and 75% of essential criteria could be found in 25.5% of MRI reportings. During the second period (73 MRI performed), the protocol used by 6.8% of MR images abided by the 2016 Society of Gastrointestinal and Abdominal Radiology(ESGAR) recommendations and 39.7% abided by the Society of Abdominal Radiology (SAR) recommendations. 75% of essential criteria could be found in 52.3% of MRI reportings and 90% of essential criteria could be found in 6.2% of MRI reportings. In an era of increasing individualized patient care and conservative treatment focused on tumour response and prognostic factors, the present study showed that compliance to MRI protocols and reporting guidelines needs improving to upgrade patient care.

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

BackgroundRectal 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.MethodsA 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.ResultsThere 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.ConclusionsPreoperative 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.

MRI in Evaluation of Rectal Cancer pre- and post-Chemo-Radiation Treatment.

Rectal cancer is associated with a high risk of metastases and local recurrence; local recurrence rates after surgical treatment being up to 32%. An accurate local staging at the time of initial diagnosis is therefore very important. Magnetic Resonance Imaging (MRI) is already established as an accurate tool for the preoperative staging of rectal cancer and has resulted in marked improvements in staging accuracy.&#x0D; Material and Methods: This study used MRI in comparing the morphologic features of rectal cancer before and after 8 weeks of chemo-radiation treatment (CRT) and to correlate the post treatment MRI appearances with the histological findings in resected tumors. 45 patients with histo-pathologically proven rectal adenocarcinoma received standardized 8 weeks chemo-radiation therapy and subjected to MRI before and after treatment for clinical staging. A correlation between pathological response and MRI findings was done.&#x0D; Results: The MRI diagnostic accuracy to diagnose T2 is 74.2% with relatively low specificity (64.7%). The diagnostic accuracy of MRI in evaluation of stage T3 and T4, the MRI sensitivity was 96.2% however of low specificity 26.3%. The diagnostic accuracy was 66.7%. Additionally, in evaluation of T2 stage, the sensitivity of MRI was very low 27.3% and specificity relatively high 94.7%. Diagnostic accuracy was 70%.&#x0D; Post RCT, based on downstaging after CRT, the sensitivity of MRI to show no tumor was very low 0% with diagnostic accuracy 88.9%. However, to evaluate stage T2, the sensitivity was 84.6% with low specificity 66.7% and the diagnostic accuracy was 74.2%.&#x0D; Conclusion: MRI had an accuracy average of 81.6% in T stage and 68.9% in N stage in re-staging rectal tumors after CRT. Over-staging results of majority of the inaccuracy. The statistical agreement between post-CRT MRI and the pathologic staging involving T and N stages was not satisfactory. In view of the above, Post CRT, restaging rectal cancer remains a challenge.

Intra- and interobserver agreement of rectal cancer staging with MRI.

Reliable preoperative staging of rectal cancers is crucial for treatment decision making. To assess the intra- and inter-observer agreement of rectal cancer staging, including the sub-categories, with magnetic resonance imaging (MRI). The study includes 85 patients (35.3% women; mean age = 62.2 ± 11.2 years) who underwent MRI for rectal cancer staging between August 2020 and April 2021. All the stored images were evaluated independently by two radiologists with 10-15 years of experience. For intra-observer agreement, the evaluations were done two months apart. Analyses were made using kappa, prevalence and bias-adjusted kappa (PABAK), and intraclass correlation coefficient (ICC), where appropriate. There was a substantial inter-observer agreement for tumor localization (kappa = 0.665, PABAK = 0.682), mesorectal fascia invasion (kappa = 0.663, PABAK = 0.822), internal and external sphincter involvement (kappa 0.804 and 0.751, PABAK 0.859 and 0.929, respectively), and moderate to substantial agreement for M-staging (kappa = 0.451, PABAK = 0.742) and extramural vascular invasion (kappa = 0.569, PABAK = 0.741). There was also a good inter-observer agreement for T staging and N staging (ICC = 0.862, 95% confidence interval [CI] = 0.788-0.911; and ICC = 0.841, 95% CI = 0.595-0.922, respectively). As expected, intra-observer agreement was better than inter-observer agreement. Intra- and inter-observer agreement for MRI staging of rectal cancers using the structured reporting template is good.

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.

Retrospective audit: Utility of PET scan in routine preoperative rectal cancer staging.

Accurate staging for rectal cancer is pertinent with recent introduction of rectum-sparing approaches for patients showing complete clinical response on restaging. Positron emission tomography(PET) is used in detection of recurrence or metastasis, but its value in routine preoperative rectal cancer staging remains unclear. Studies report that preoperative PET altered the stage in 39% and changed the management in 17-27% of patients. Our study aims to look at the utility of PET in routine preoperative staging of rectal cancer within 2 two colorectal units, and to determine if PET did result in a change in management. Patients in Nepean Hospital (NSW) and Peter MacCallum Cancer Centre (VIC) who were diagnosed with rectal cancer between 1 January 2017 and 31 December 2021 were included in this retrospective study. All patients who did not have a PET scan were excluded. PET scan results were then compared with MRI and CT results. Three hundred and fifty-seven patients were included in the study. 30.3% of the patients had Stage 3 rectal cancer. 71.7% received neoadjuvant therapy. PET scan provided additional information in 55.5% of patients when compared with CT and MRI alone; 18.2% of the PET findings resulted in an altered management for the patient. PET scan can be a valuable tool in accurate staging, especially for ambiguous or equivocal lesions on CT. Our study demonstrated that additional information from PET scan resulted in an altered management plan in 18.2% of the patients. PET/MRI as a newer modality may be more accurate with reduced radiation exposure.

Comparison of Computed and Acquired DWI in the Assessment of Rectal Cancer: Image Quality and Preoperative Staging.

ObjectiveThe aim of the study was to evaluate the computed diffusion-weighted images (DWI) in image quality and diagnostic performance of rectal cancer by comparing with the acquired DWI.MethodsA total of 103 consecutive patients with primary rectal cancer were enrolled in this study. All patients underwent two DWI sequences, namely, conventional acquisition with b = 0 and 1,000 s/mm2 (aDWIb1,000) and another with b = 0 and 700 s/mm2 on a 3.0T MR scanner (MAGNETOM Prisma; Siemens Healthcare, Germany). The images (b = 0 and 700 s/mm2) were used to compute the diffusion images with b value of 1,000 s/mm2 (cDWIb1,000). Qualitative and quantitative analysis of both computed and acquired DWI images was performed, namely, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and signal intensity ratio (SIR), and also diagnostic staging performance. Interclass correlation coefficients, weighted κ coefficient, Friedman test, Wilcoxon paired test, and McNemar or Fisher test were used for repeatability and comparison assessment.ResultsCompared with the aDWIb1,000 images, the cDWIb1,000 ones exhibited significant higher scores of subjective image quality (all P <0.050). SNR, SIR, and CNR of the cDWIb1,000 images were superior to those of the aDWIb1,000 ones (P <0.001). The overall diagnostic accuracy of computed images was higher than that of the aDWIb1,000 images in T stage (P <0.001), with markedly better sensitivity and specificity in distinguishing T1–2 tumors from the T3–4 ones (P <0.050).ConclusioncDWIb1,000 images from lower b values might be a useful alternative option and comparable to the acquired DWI, providing better image quality and diagnostic performance in preoperative rectal cancer staging.

Histogram analysis based on multi-parameter MR imaging as a biomarker to predict lymph node metastasis in T3 stage rectal cancer

BackgroundPreoperative identification of rectal cancer lymph node status is crucial for patient prognosis and treatment decisions. Rectal magnetic resonance imaging (MRI) plays an essential role in the preoperative staging of rectal cancer, but its ability to predict lymph node metastasis (LNM) is insufficient. This study explored the value of histogram features of primary lesions on multi-parametric MRI for predicting LNM of stage T3 rectal carcinoma.MethodsWe retrospectively analyzed 175 patients with stage T3 rectal cancer who underwent preoperative MRI, including diffusion-weighted imaging (DWI) before surgery. 62 patients were included in the LNM group, and 113 patients were included in the non-LNM group. Texture features were calculated from histograms derived from T2 weighted imaging (T2WI), DWI, ADC, and T2 maps. Stepwise logistic regression analysis was used to screen independent predictors of LNM from clinical features, imaging features, and histogram features. Predictive performance was evaluated by receiver operating characteristic (ROC) curve analysis. Finally, a nomogram was established for predicting the risk of LNM.ResultsThe clinical, imaging and histogram features were analyzed by stepwise logistic regression. Preoperative carbohydrate antigen 199 level (p = 0.009), MRN stage (p < 0.001), T2WIKurtosis (p = 0.010), DWIMode (p = 0.038), DWICV (p = 0.038), and T2-mapP5 (p = 0.007) were independent predictors of LNM. These factors were combined to form the best predictive model. The model reached an area under the ROC curve (AUC) of 0.860, with a sensitivity of 72.8% and a specificity of 85.5%.ConclusionThe histogram features on multi-parametric MRI of the primary tumor in rectal cancer were related to LN status, which is helpful for improving the ability to predict LNM of stage T3 rectal cancer.

The role of magnetic resonance imaging and magnetic resonance diffusion weighted image in preoperative staging of rectal cancer in comparison to postoperative histopathology

Background: With outstanding soft tissue contrast, functional imaging capabilities, and multiplanar capacity, high-resolution phased-array magnetic resonance imaging MRI is considered as a basic imaging modality for preoperative local staging of rectal cancer. And so MRI fills a void in clinical practice by allowing for precise local staging of rectal cancer prior to treatment decisions. The diffusion-weighted image used as enhancing utility for MRI in patients with rectal cancer. Objectives: The aim of work was to assess the role of MRI imaging including the (diffusion weighted imaging DWI and Apparent diffusion coefficient ADC map) in preoperative rectal cancer staging, in comparison to post-operative histopathology. Patients and methods: A total of 50 patients were included in the study, presented to South Valley University hospital and underwent MRI examination in MRI unit at South Valley University hospital. Results: Regarding the circumferential resection margin (CRM) infiltration, MRI diagnosed CRM involvement in 15 cases while rest 35 cases showing free CRM. From these positive cases only 13 were truly positive with histopathology, other two cases proved to be positive with histopathology not diagnosed by MRI. MRI showed MRF infiltration in only 18 cases. Histopathological assessment showed that MRF infiltration in only 15 cases and the rest 35 cases showing free MRF (agreement 83.3%). Conclusion: The results of this study demonstrate that preoperative MRI has a great value in achieving the best treatment strategy through accurate staging of rectal cancer, prediction of negative CRMs and involvement of the perirectal and pelvic LNs.

MRI-Pathology Agreement in Rectal Cancer: Real-World Data from a Prospective Rectal Cancer Registry.

Introduction: Magnetic Resonance Imaging (MRI) is routinely used in preoperative rectal cancer staging. The concordance of MRI staging with final pathologic exam, albeit improved, has not yet reached perfection. The aim of this study is to analyze the agreement between MRI and pathologic exam in patients operated on for mid-low rectal cancer. Material and Method: Patients undergoing neoadjuvant chemoradiation therapy (nCRT) or upfront surgery were analyzed. Between January 2019 to December 2019, 140 patients enrolled in the AIMS Academy rectal cancer registry were analyzed. Sixty-two patients received nCRT and 78 underwent upfront surgery. Results: Overall, the agreement between MRI and pathologic exam on T stage and N stage were 64.7% and 69.2%, respectively. The agreement between MRI and pathologic exam on T stage was 62.7% for patients who did not receive nCRT and 67.4% for patients who received nCRT (p = 0.62). The agreement on N stage was 76.3% for patients who did not receive nCRT and 60.0% for patients who received nCRT (p = 0.075). Conclusions: Real-world data shows MRI is still far from being able to correlate with the pathology findings which raises questions about the accuracy of the real-life decision-making process during cancer boards.

Application value of endoscopic ultrasonography combined with enhanced MRI in preoperative staging of rectal cancer

Application value of endoscopic ultrasonography combined with enhanced MRI in preoperative staging of rectal cancer

Role of MRI in Detection and Local Staging of Rectal Cancer

Abstract Background: Colorectal cancer is one of the most frequent causes of cancer-related death worldwide. An accurate preop-erative rectal cancer staging is crucial to the correct manage-ment of the disease. Despite great controversy around this issue, pelvic magnetic resonance is said to be the standard modality. Aim of Study: The aim of this study is to assess the role of MRI in detection and local staging of rectal cancer. Patients and Methods: 30 patients with rectal carcinoma were included with MRI and histopathological assessment of cancer staging to evaluate MRI accuracy. All patients received pre-operative neoadjuvant chemotherapy. Results: T3 staging with MRI, calculation of sensitivity, specificity, negative and positive predictive value were 73.3%, 40%, 60% and 55% respectively. T4 staging with MRI, cal-culation of sensitivity, specificity, negative and positive predictive value were 100%, 77%, 100% and 40% respectively. Conclusion: MRI has a good sensitivity for tumor staging and nodal staging.

Shear Wave Elastography in Rectal Cancer Staging, Compared with Endorectal Ultrasonography and Magnetic Resonance Imaging

The goal of the study described here was to investigate the value of shear wave elastography (SWE) in pre-operative staging of rectal cancer. Fifty-five patients with rectal cancer underwent pre-operative conventional endorectal ultrasonography (ERUS), SWE and enhanced magnetic resonance imaging (MRI) examinations. Pathologic results were used as the gold standard for cancer staging. The concordance rate with pathologic stage by ERUS and MRI and the stiffness values measured by SWE for tumors in different stages were compared. The concordance rates for cancer staging were 72.7% and 70.9% for conventional ERUS and enhanced MRI, respectively; the difference was not significant (p > 0.05). SWE indicated that the mean and maximum stiffness values of the tumors increased with advance in stage. The differences in stiffness values between T1 and T2, T1 and T3–4, as well as T2 and T3–4, were all statistically significant (p < 0.001). When the maximum stiffness values of 65.0 and 90.7 kPa are used for the diagnosis of T1, T2 and local advanced rectal cancer, the concordance rate of cancer staging was 85.5%, which was slightly higher than those of ERUS and MRI, although the difference was not statistically significant (p > 0.05). SWE is useful in judging the depth of invasion of rectal tumors. The value of tumor stiffness can provide a quantifiable indicator for pre-operative diagnosis of cancer staging and can be used as a supplement to conventional ERUS. Further studies with larger sample sizes are needed.

Accuracy of endoscopic ultrasound in rectal cancer and its use in transanal endoscopic microsurgery

Introduction: This study evaluated the accuracy of endoscopic ultrasound (EUS) for preoperative staging of rectal cancer and guiding the treatment of transanal endoscopic microsurgery (TEM) in early rectal cancer.Material and methods: One-hundred-twenty-six patients with rectal cancer were staged preoperatively using EUS and the results were compared with postoperative histopathology results. Radical surgeries, including low anterior resection (LAR), abdominal-perineal resection (APR) and Hartmann surgeries, were performed on patients with advanced rectal cancers, and TEM was performed on patients with stage T1. The Kappa statistic was used to determine agreement between EUS-based staging and pathology staging.Results: The overall accuracies of EUS for T and N stage were 90.8% (Kappa = 0.709) and 76.7% (Kappa = 0.419), respectively. The accuracies of EUS for uT1, uT2, uT3, and uT4 stages were 96.8%, 92.1%, 84.1%, and 88.9%, respectively, and for uN0, uN1, and uN2 stages, they were 71.9%, 64.9%, and 93.0%, respectively. Twelve patients underwent TEM and received confirmed pathology results of early rectal cancer. After postoperative follow-up, there were no local recurrences or distant metastases.Conclusion: EUS is a good and comparable technique for postoperative staging of rectal cancer. Moreover, EUS is used as indicator for preoperative staging and tumor assessment strategy when considering TEM.

Standardised reports with a template format are superior to free text reports: the case for rectal cancer reporting in clinical practice

PurposeRectal cancer staging with magnetic resonance imaging (MRI) allows accurate assessment and preoperative staging of rectal cancers. Therefore, complete MRI reports are vital to treatment planning. Significant variability may exist in their content and completeness. Template-style reporting can improve reporting standards, but its use is not widespread. Given the implications for treatment, we have evaluated current clinical practice amongst specialist gastrointestinal (GI) radiologists to measure the quality of rectal cancer staging MRI reports.Materials and methodsSixteen United Kingdom (UK) colorectal cancer multi-disciplinary teams (CRC-MDTs) serving a population over 5 million were invited to submit up to 10 consecutive rectal cancer primary staging MRI reports from January 2016 for each radiologist participating in the CRC-MDT. Reports were compared to a reference standard based on recognised staging and prognostic factors influencing case managementResultsFour hundred ten primary staging reports were submitted from 41 of 42 (97.6%) eligible radiologists. Three hundred sixty reports met the inclusion criteria, of these, 81 (22.5%) used a template. Template report usage significantly increased recording of key data points versus non-template reports for extra-mural venous invasion (EMVI) status (98.8% v 51.6%, p < 0.01) and circumferential resection margin (CRM) status (96.3% v 65.9%, p < 0.01). Local tumour stage (97.5% v 93.5%, NS) and nodal status (98.8% v 96.1%, NS) were reported and with similar frequency.ConclusionRectal cancer primary staging reports do not meet published standards. Template-style reports have significant increases in the inclusion of key tumour descriptors. This study provides further support for their use to improve reporting standards and outcomes in rectal cancer.Key Points• MRI primary staging of rectal cancer requires detailed tumour descriptions as these alter the neoadjuvant and surgical treatments.• Currently, rectal cancer MRI reports in clinical practice do not provide sufficient detail on these tumour descriptors.• The use of template-style reports for primary staging of rectal cancer significantly improves report quality compared to free-text reports.

Efficacy of transrectal ultrasonography (TRUS) in preoperative staging of rectal cancer

Background/Aim. The outcome of rectal cancer is dependant on the stage of the tumour. There are several classification systems used to describe the extent of the disease. The aim of this study was to compare the efficacy of transrectal ultrasonography (TRUS) in preoperative local staging of rectal cancer using endosonographic probes with different views (180? vs 360?), as well as an influence of experience of an endoscopist on the TRUS performance. Methods. TRUS was performed in 127 patients with rectal carcinoma by two endoscopists. Seventy-one patients were examined with a 180? endosonographic probe (group A) and 56 patients with a 360? rotating probe (group B). All findings were compared with a histopathology report. Results. TRUS had a diagnostic overall accuracy of 91.3% for the tumor (T) category (k = 0.866, SE (k) = 0.038, p &lt; 0.0001) and 71.7% for the node (N) category (? = 0.374, SE (k) = 0.082, p &lt; 0.0001). In the group A, TRUS had a diagnostic overall accuracy of 88.7% for the T category (? = 0.805, SE (k) = 0.063, p &lt; 0.0001), and 70.4% for the N category (? = 0.376, SE (k) = 0.101, P &lt; 0.0001). In the group B, TRUS had a diagnostic overall accuracy of 94.6% for the T category (? = 0.920, SE (k) = 0.044, p &lt; 0.0001), and 73.2% for the N category (? = 0.379, SE (k) = 0.131, p = 0.004). Experience of the endoscopist had no significant influence on results of preoperative staging of rectal cancer by using TRUS. Conclusion. The accuracy rate of TRUS in the preoperative local staging of rectal cancer is high. Our results imply no significant difference in the overall accuracy rates when using endosonographic probes with different views (180? vs 360?). Also, there was no significant influence of endoscopist experience on results obtained.

Significance of MRI in rectal carcinoma therapy optimization - correlation of preoperative T- and N-staging with definitive histopathological findings.

In past decades, both prognosis and therapy of rectal cancer patients showed significant improvement, on the other hand, the incidence of rectal carcinoma continues to have a rising tendency. According to current UICC classification, patients in stage II rectal cancer or higher are indicated for neoadjuvant chemoradiotherapy (nCRT). Magnetic resonance imaging (MRI) is currently the most common diagnostic method used for preoperative staging of rectal cancer. Several studies already pointed out the inaccuracy of preoperative lymph node staging in patients with rectal cancer. The present study analyzed overall accuracy of MRI staging of rectal cancer and thus its accuracy in neoadjuvant therapy indication, by comparing preoperative MRI staging with definitive histopathologic results from resected tumors. This study evaluated cases of 92 patients with rectal tumor that underwent MRI examination followed by surgical resection. Tumors included in the analysis were ranging from T1 to T3b according to TNM staging, with free circumferential resection margin (CRM), distance form mesorectal fascia more than 5 mm, negative intersphincteric plane and also negative extramural venous invasion (EMVI), while the N stage was not decisive. In all cases both N-staging and T-staging were evaluated histologically and compared with preoperative MRI results. Significant difference in preoperative and postoperative N-staging was shown in 51 patients (61.45%). In majority of cases MRI lead to overstaging, which was observed in 44 cases (53.1 %), with complete negativity of lymph nodes proven by histological examination in 34 cases. On the other hand, understaging of lymph nodes was observed only in 7 cases (7.4 %). The T-staging did not show significant differences. Results from this study confirm that MRI plays an important role in T-staging of rectal tumors, however, there are admittedly issues in N-staging of tumors, which should lead to reevaluation of neoadjuvant therapy indication in patients with positive lymph nodes according to MRI examination. Based on the results of this study, we see the future of preoperative staging of rectal tumors in precise T-staging together with accurate assessment of CRM and distance of tumor from mesorectal fascia as well as evaluation of intersphinteric plane and EMVI.

Reprint of: Important imaging considerations in the pre-operative assessment of rectal cancer

The role of imaging has become central in the pre-operative decision-making process for patients with rectal cancer. The detailed information that is available from high-resolution imaging studies not only provides prognostic information but also allows the surgeon to anticipate potential pitfalls during the operation. The greater the amount of detail known about the tumour, the more selective one can be in the use of pre-operative radiotherapy, which can reduce unnecessary morbidity for minimal gain. Magnetic resonance imaging (MRI) is the most useful modality for the local staging of rectal cancer as it provides the most detail on the important prognostic factors that influence treatment. These include height of tumour from the anal verge, tumour depth of penetration, nodal disease, venous invasion, involvement of the circumferential resection margin. However, endoanal ultrasound (EAUS) is particularly good at staging early tumours and aids in identifying those that are suitable for local excision. We review the important considerations in the pre-operative staging of rectal cancer.

Improving the Quality of MRI Reports of Preoperative Patients With Rectal Cancer: Effect of National Guidelines and Structured Reporting.

Since the implementation of new guidelines for rectal cancer in The Netherlands in April 2014, clinical stage as seen at preoperative MRI indicates whether neoadjuvant therapy is necessary before rectal cancer surgery. Therefore, the importance of correct MRI interpretation has increased. The aim of this study was to evaluate the completeness of MRI reports of rectal cancer and the effect of implementation of the new guidelines and standardized reporting on the completeness of these reports. Data were collected from all patients who consecutively underwent rectal cancer surgery at one hospital between January 2011 and July 2017. Data were extracted from electronic patient records. The study included 492 MRI examinations. Before implementation of the new guidelines, a median of 4 of 10 items (interquartile range [IQR], 3-6 items) were described in each MRI report. After implementation of the new guidelines, the number of items described improved significantly (median, 7 items; IQR, 6-8 items; p < 0.001). Implementation of a standardized report led to further significant improvement (median, 9 items; IQR, 9-10 items; p < 0.001). The items scored most frequently were distance between the tumor and the anal verge (85.6%) and length of the tumor (87.6%). The items scored least were presence or absence of extramural venous invasion (21.1%) and morphologic features of the tumor (24.6%). Implementation of a standardized protocol and a standardized reporting system for MRI in preoperative staging of rectal cancer results in a more complete MRI report.

Diagnostic value of endoscopic ultrasonography in staging of rectal cancer

Objective To evaluate the diagnostic value of endoscopic ultrasonography (EUS) in staging of rectal cancer (RC). Methods From January 2015 to January 2017, the clinical data of 204 patients with RC and received EUS and surgery were retrospectively analyzed. Patients were divided into surgery alone group (155 cases) and preoperative neoadjuvant chemoradiation therapy (CRT) plus surgery group (49 cases). The preoperative staging by EUS and postoperative pathological staging of two groups were compared. Kappa test was performed for statistical analysis. Results Compared with postoperative pathologic diagnosis, the accuracy rate of EUS in the evaluation of invasion depth of RC in surgery alone group was 81.9% (127/155), and the accuracy rates in the diagnosis of Tis, T1, T2, T3 and T4 were 3/4, 11/13, 82.1%(32/39), 91.1%(41/45) and 74.1%(40/54), respectively, with a good consistency (kappa=0.751, P<0.01). However, the accuracy rate of EUS in the invasion depth of RC in CRT plus surgery group was 34.7% (17/49), and the accuracy rates in the diagnosis of T2, T3 and T4 were 1/13, 2/7 and 14/16, respectively, with a poor consistency (kappa=0.107, P=0.850). Compared with postoperative pathologic diagnosis, the diagnostic accuracy rate of EUS in evaluating regional lymph node metastasis in surgery alone group was 70.3% (109/155), and the accuracies in the diagnosis of cases with or without regional lymph node metastasis were 40.7% (24/59) and 88.5% (85/96), respectively, with a poor consistency (kappa=0.317, P<0.01). The diagnostic accuracy rate of EUS in evaluating regional lymph node metastasis of preoperative CRT plus surgery group was 51.0% (25/49), and the accuracies in the diagnosis of cases with or without regional lymph node metastasis were 5/11 and 52.6% (20/38), respectively, with a poor consistency (kappa=0.014, P=0.911). Conclusions EUS can accurately evaluate the depth of tumor invasion and lymph node metastasis in preoperative staging of RC, which may be helpful for determining clinical treatment strategy. However, for patients received CRT treatment, EUS has a limited value in diagnosing and staging the tumor. Key words: Rectal neoplasms; Endosonography; Neoplasm staging; Diagnosis