The value of four imaging modalities in diagnosing lymph node involvement in rectal cancer: an overview and adjusted indirect comparison. Clin Exp Med. 2019;19:225-234. [PMID: 30900099 DOI: 10.1007/s10238-019-00552-z]

Ultra-high b-value DWI in rectal cancer: image quality assessment and regional lymph node prediction based on radiomics

OBJECTIVES

This study aims to evaluate image quality and regional lymph node metastasis (LNM) in patients with rectal cancer (RC) on multi-b-value diffusion-weighted imaging (DWI).

METHODS

This retrospective study included 199 patients with RC who had undergone multi-b-value DWI. Subjective (five-point Likert scale) and objective assessments of quality images were performed on DWIb1000, DWIb2000, and DWIb3000. Patients were randomly divided into a training (n = 140) or validation cohort (n = 59). Radiomics features were extracted within the whole volume tumor on ADC maps (b = 0, 1000 s/mm2), DWIb1000, DWIb2000, and DWIb3000, respectively. Five prediction models based on selected features were developed using logistic regression analysis. The performance of radiomics models was evaluated with a receiver operating characteristic curve, calibration, and decision curve analysis (DCA).

RESULTS

The mean signal intensity of the tumor (SItumor), signal-to-noise ratio (SNR), and artifact and anatomic differentiability score gradually were decreased as the b-value increased. However, the contrast-to-noise (CNR) on DWIb2000 was superior to those of DWIb1000 and DWIb3000 (4.58 ± 0.86, 3.82 ± 0.77, 4.18 ± 0.84, p < 0.001, respectively). The overall image quality score of DWIb2000 was higher than that of DWIb3000 (p < 0.001) and showed no significant difference between DWIb1000 and DWIb2000 (p = 0.059). The area under curve (AUC) value of the radiomics model based on DWIb2000 (0.728) was higher than conventional ADC maps (0.690), DWIb1000 (0.699), and DWIb3000 (0.707), but inferior to multi-b-value DWI (0.739) in predicting LNM.

CONCLUSION

DWIb2000 provides better lesion conspicuity and LNM prediction than DWIb1000 and DWIb3000 in RC.

CLINICAL RELEVANCE STATEMENT

DWIb2000 offers satisfactory visualization of lesions. Radiomics features based on DWIb2000 can be applied for preoperatively predicting regional lymph node metastasis in rectal cancer, thereby benefiting the stratified treatment strategy.

KEY POINTS

Lymph node staging is required to determine the best treatment plan for rectal cancer. DWIb2000 provides superior contrast-to-noise ratio and lesion conspicuity and its derived radiomics best predict lymph node metastasis. DWIb2000 may be recommended as the optimal b-value in rectal MRI protocol.

Radiomics analysis of dual-layer spectral-detector CT-derived iodine maps for predicting tumor deposits in colorectal cancer

OBJECTIVE

To investigate the value of radiomics analysis of dual-layer spectral-detector computed tomography (DLSCT)-derived iodine maps for predicting tumor deposits (TDs) preoperatively in patients with colorectal cancer (CRC).

MATERIALS AND METHODS

A total of 264 pathologically confirmed CRC patients (TDs + (n = 80); TDs - (n = 184)) who underwent preoperative DLSCT from two hospitals were retrospectively enrolled, and divided into training (n = 124), testing (n = 54), and external validation cohort (n = 86). Conventional CT features and iodine concentration (IC) were analyzed and measured. Radiomics features were derived from venous phase iodine maps from DLSCT. The least absolute shrinkage and selection operator (LASSO) was performed for feature selection. Finally, a support vector machine (SVM) algorithm was employed to develop clinical, radiomics, and combined models based on the most valuable clinical parameters and radiomics features. Area under receiver operating characteristic curve (AUC), calibration curves, and decision curve analysis were used to evaluate the model's efficacy.

RESULTS

The combined model incorporating the valuable clinical parameters and radiomics features demonstrated excellent performance in predicting TDs in CRC (AUCs of 0.926, 0.881, and 0.887 in the training, testing, and external validation cohorts, respectively), which outperformed the clinical model in the training cohort and external validation cohorts (AUC: 0.839 and 0.695; p: 0.003 and 0.014) and the radiomics model in two cohorts (AUC: 0.922 and 0.792; p: 0.014 and 0.035).

CONCLUSION

Radiomics analysis of DLSCT-derived iodine maps showed excellent predictive efficiency for preoperatively diagnosing TDs in CRC, and could guide clinicians in making individualized treatment strategies.

CLINICAL RELEVANCE STATEMENT

The radiomics model based on DLSCT iodine maps has the potential to aid in the accurate preoperative prediction of TDs in CRC patients, offering valuable guidance for clinical decision-making.

KEY POINTS

Accurately predicting TDs in CRC patients preoperatively based on conventional CT features poses a challenge. The Radiomics model based on DLSCT iodine maps outperformed conventional CT in predicting TDs. The model combing DLSCT iodine maps radiomics features and conventional CT features performed excellently in predicting TDs.

A clinical-radiomics nomogram based on spectral CT multi-parameter images for preoperative prediction of lymph node metastasis in colorectal cancer

To develop a clinical-radiomics nomogram based on spectral CT multi-parameter images for predicting lymph node metastasis in colorectal cancer. A total of 76 patients with colorectal cancer and 156 lymph nodes were included. The clinical data of the patients were collected, including gender, age, tumor location and size, preoperative tumor markers, etc. Three sets of conventional images in the arterial, venous, and delayed phases were obtained, and six sets of spectral images were reconstructed using the arterial phase spectral data, including virtual monoenergetic images (40 keV, 70 keV, 100 keV), iodine density maps, iodine no water maps, and virtual non-contrast images. Radiomics features of lymph nodes were extracted from the above images, respectively. Univariate analysis and least absolute shrinkage and selection operator (LASSO) regression were used to select features. A clinical model was constructed based on age and carcinoembryonic antigen (CEA) levels. The radiomics features selected were used to generate a composed radiomics signature (Com-RS). A nomogram was developed using age, CEA, and the Com-RS. The models' prediction efficiency, calibration, and clinical application value were evaluated by the area under the receiver operating characteristic curve (AUC), calibration curve, and decision curve analysis, respectively. The nomogram outperforms the clinical model and the Com-RS (AUC = 0.879, 0.824). It is well calibrated and has great clinical application value. This study developed a clinical-radiomics nomogram based on spectral CT multi-parameter images, which can be used as an effective tool for preoperative personalized prediction of lymph node metastasis in colorectal cancer.

Contrast-enhanced endoscopic ultrasound for swollen lymph nodes

Endoscopic ultrasound (EUS) is an important tool for the evaluation of lymphadenopathy, especially in intra-thoracic or intra-abdominal regions. EUS also provides tissue diagnosis via EUS fine-needle aspiration or biopsy. To select the target for biopsy or aspiration, conventional B-mode images are used for the evaluation, but this approach still lacks diagnostic accuracy. Contrast-enhanced EUS has been used to evaluate the vascularity of lesions. Most malignant lymphadenopathy shows heterogenous enhancement or defect of enhancement, while quantitative studies using time-intensity curves in contrast-enhanced harmonic EUS show a rapid decline in enhancement pattern. These findings are useful as an auxiliary method for tissue diagnosis or in cases in which tissue diagnosis is contraindicated.

DIAGNOSTICS OF LYMPHOGENIC METASTASIS IN PATIENTS WITH RECTAL CANCER BY COMBINING MRI WITH BLOOD CEA ASSESSMENT

AIM

To improve the diagnostics of lymphogenic metastasis in patients with rectal cancer (RCa) by combining magnetic resonance imaging (MRI) with the blood carcinoembryonic antigen (CEA) level assessment.

MATERIALS AND METHODS

We have systematized and analyzed the results of the examination and treatment of 77 patients with stage II-III rectal adenocarcinoma (T2-3N0-2M0). Before the start of neoadjuvant treatment as well as 8 weeks after its completion, computed tomography (CT) and MRI were performed. We analyzed such prognostic criteria as the size, shape, and structure of lymph nodes as well as the patterns of contrast accumulation. As a prognostic marker, CEA levels in the blood of patients with RCa before surgical treatment were assessed.

RESULTS

Radiological exams showed a rounded shape and heterogeneous structure to be the most informative for predicting metastatic lymph node damage, increasing the probability by 4.39 and 4.98 times, respectively. After neoadjuvant treatment, the percentage of positive histopathological reports on lymph node involvement decreased significantly to 21.6% (р ˂ 0.001). MRI showed 76% sensitivity and 48% specificity for assessing lymphogenic metastasis. CEA levels differed significantly between stages II and III (N1-2) (р ˂ 0.032) with a threshold value of 3.95 ng/ml.

CONCLUSIONS

In order to increase the effectiveness of the diagnosis of lymphogenic metastasis using radiological examination methods in RCa patients, such prognostic criteria as the round shape and heterogeneous structure of the lymph nodes and the threshold level of CEA should be considered.

Obesity and main urologic cancers: Current systematic evidence, novel biological mechanisms, perspectives and challenges

Urologic cancers (UC) account for 13.1% of all new cancer cases and 7.9% of all cancer-related deaths. A growing body of evidence has indicated a potential causal link between obesity and UC. The aim of the present review is to appraise in a critical and integrative manner evidence from meta-analyses and mechanistic studies on the role of obesity in four prevalent UC (kidney-KC, prostate-PC, urinary bladder-UBC, and testicular cancer-TC). Special emphasis is given on Mendelian Randomization Studies (MRS) corroborating a genetic causal association between obesity and UC, as well as on the role of classical and novel adipocytokines. Furthermore, the molecular pathways that link obesity to the development and progression of these cancers are reviewed. Available evidence indicates that obesity confers increased risk for KC, UBC, and advanced PC (20-82%, 10-19%, and 6-14%, respectively), whereas for TC adult height (5-cm increase) may increase the risk by 13%. Obese females tend to be more susceptible to UBC and KC than obese males. MRS have shown that a higher genetic-predicted BMI may be causally linked to KC and UBC but not PC and TC. Biological mechanisms that are involved in the association between excess body weight and UC include the Insulin-like Growth Factor axis, altered availability of sex hormones, chronic inflammation and oxidative stress, abnormal secretion of adipocytokines, ectopic fat deposition, dysbiosis of the gastrointestinal and urinary tract microbiomes and circadian rhythm dysregulation. Anti-hyperglycemic and non-steroidal anti-inflammatory drugs, statins, and adipokine receptor agonists/antagonists show potential as adjuvant cancer therapies. Identifying obesity as a modifiable risk factor for UC may have significant public health implications, allowing clinicians to tailor individualized prevention strategies for patients with excess body weight.

A Dual-Energy CT Radiomics of the Regional Largest Short-Axis Lymph Node Can Improve the Prediction of Lymph Node Metastasis in Patients With Rectal Cancer

Objective

To explore the value of dual-energy computed tomography (DECT) radiomics of the regional largest short-axis lymph nodes for evaluating lymph node metastasis in patients with rectal cancer.

Materials and Methods

One hundred forty-one patients with rectal cancer (58 in LNM+ group, 83 in LNM- group) who underwent preoperative total abdominal DECT were divided into a training group and testing group (7:3 ratio). After post-processing DECT venous phase images, 120kVp-like images and iodine (water) images were obtained. The highest-risk lymph nodes were identified, and their long-axis and short-axis diameter and DECT quantitative parameters were measured manually by two experienced radiologists who were blind to the postoperative pathological results. Four DECT parameters were analyzed: arterial phase (AP) normalized iodine concentration, AP normalized effective atomic number, the venous phase (VP) normalized iodine concentration, and the venous phase normalized effective atomic number. The carcinoembryonic antigen (CEA) levels were recorded one week before surgery. Radiomics features of the largest lymph nodes were extracted, standardized, and reduced before modeling. Radomics signatures of 120kVp-like images (Rad-signature120kVp) and iodine map (Rad-signatureImap) were built based on Logistic Regression via Least Absolute Shrinkage and Selection Operator (LASSO).

Results

Eight hundred thirty-three features were extracted from 120kVp-like and iodine images, respectively. In testing group, the radiomics features based on 120kVp-like images showed the best diagnostic performance (AUC=0.922) compared to other predictors [CT morphological indicators (short-axis diameter (AUC=0.779, IDI=0.262) and long-axis diameter alone (AUC=0.714, IDI=0.329)), CEA alone (AUC=0.540, IDI=0.414), and normalized DECT parameters alone (AUC=0.504-0.718, IDI=0.290-0.476)](P&lt;0.05 in Delong test). Contrary, DECT iodine map-based radiomic signatures showed similar performance in predicting lymph node metastasis (AUC=0.866). The decision curve showed that the 120kVp-like-based radiomics signature has the highest net income.

Conclusion

Predictive model based on DECT and the largest short-axis diameter lymph nodes has the highest diagnostic value in predicting lymph node metastasis in patients with rectal cancer.

Endoscopic submucosal dissection for superficial gastrointestinal lesions: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2022

ESGE recommends that the evaluation of superficial gastrointestinal (GI) lesions should be made by an experienced endoscopist, using high definition white-light and chromoendoscopy (virtual or dye-based).ESGE does not recommend routine performance of endoscopic ultrasonography (EUS), computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET)-CT prior to endoscopic resection.ESGE recommends endoscopic submucosal dissection (ESD) as the treatment of choice for most superficial esophageal squamous cell and superficial gastric lesions.For Barrett's esophagus (BE)-associated lesions, ESGE suggests the use of ESD for lesions suspicious of submucosal invasion (Paris type 0-Is, 0-IIc), for malignant lesions > 20 mm, and for lesions in scarred/fibrotic areas.ESGE does not recommend routine use of ESD for duodenal or small-bowel lesions.ESGE suggests that ESD should be considered for en bloc resection of colorectal (but particularly rectal) lesions with suspicion of limited submucosal invasion (demarcated depressed area with irregular surface pattern or a large protruding or bulky component, particularly if the lesions are larger than 20 mm) or for lesions that otherwise cannot be completely removed by snare-based techniques.ESGE recommends that an en bloc R0 resection of a superficial GI lesion with histology no more advanced than intramucosal cancer (no more than m2 in esophageal squamous cell carcinoma), well to moderately differentiated, with no lymphovascular invasion or ulceration, should be considered a very low risk (curative) resection, and no further staging procedure or treatment is generally recommended.ESGE recommends that the following should be considered to be a low risk (curative) resection and no further treatment is generally recommended: an en bloc R0 resection of a superficial GI lesion with superficial submucosal invasion (sm1), that is well to moderately differentiated, with no lymphovascular invasion, of size ≤ 20 mm for an esophageal squamous cell carcinoma or ≤ 30 mm for a stomach lesion or of any size for a BE-related or colorectal lesion, and with no lymphovascular invasion, and no budding grade 2 or 3 for colorectal lesions.ESGE recommends that, after an endoscopically complete resection, if there is a positive horizontal margin or if resection is piecemeal, but there is no submucosal invasion and no other high risk criteria are met, this should be considered a local-risk resection and endoscopic surveillance or re-treatment is recommended rather than surgery or other additional treatment.ESGE recommends that when there is a diagnosis of lymphovascular invasion, or deeper infiltration than sm1, or positive vertical margins, or undifferentiated tumor, or, for colorectal lesions, budding grade 2 or 3, this should be considered a high risk (noncurative) resection, and complete staging and strong consideration for additional treatments should be considered on an individual basis in a multidisciplinary discussion.ESGE recommends scheduled endoscopic surveillance with high definition white-light and chromoendoscopy (virtual or dye-based) with biopsies of only the suspicious areas after a curative ESD.

Application Value of MRI Combined with MSCT in Diagnosis and Staging of Colon Carcinoma

Objective

To clarify the application value of magnetic resonance imaging (MRI) combined with multislice spiral computed tomography (MSCT) in the diagnosis and staging of colon carcinoma (CC).

Methods

A total of 103 patients with histopathologically diagnosed CC were enrolled. Patient clinical and imaging data were collected, and MRI and MSCT images were analyzed to assess the accuracy of MRI, MSCT, and their combination in diagnosing tumor (T) staging of CC.

Results

Among the 103 cases of histopathologically diagnosed CC, 26 cases (25.24) were in stage T1-2, 72 cases (69.90) were in stage T3, and 5 cases (4.85) were in stage T4. The accuracy of MRI in diagnosing stage T1-2, T3, and T4 was 80.77%, 88.89%, and 60.00%, respectively, with an average of 76.55%. The accuracy rates of MSCT in diagnosing T1-2, T3, and T4 stages were 73.08%, 90.27%, and 60.00%, respectively, with an average of 74.45%. The accuracy rates of MRI+MSCT in diagnosing T1-2, T3, and T4 were 88.46%, 95.83%, and 80.00%, respectively, with an average of 88.10%.

Conclusions

Compared with single use of MRI or MSCT, MRI+MSCT provides accurate imaging data with higher accuracy, which is more helpful for the T-staging evaluation of CC.

Can magnetic resonance imaging replace conventional computerized tomography for follow-up of patients with testicular cancer? A systematic review

PURPOSE

Follow-up protocols for patients with testicular cancer (TC) have significantly reduced the number of cross-sectional imaging studies to reduce radiation exposure. At present, it is unclear whether magnetic resonance imaging (MRI) could replace conventional computerized tomography (CT) imaging. The objective of this study is to summarize the scientific evidence on this topic and to review guideline recommendations with regard to the use of MRI.

METHODS

A systematic literature review was performed searching Medline and Cochrane databases for prospective studies on patients with TC in the follow-up care (last search in February 2021). Additionally, guideline recommendations for TC were screened. Data extraction and quality assessment of included studies were performed and used for a descriptive presentation of results.

RESULTS

A total of four studies including two ongoing trials were identified. Overall, the scientific evidence of prospective comparative studies is based on 102 patients. Data suggest that abdominal imaging with MRI can replace conventional CT for detection of lymph node metastasis of the retroperitoneum to spare radiation exposure and contrast media application. However, experienced radiologists are needed. Clinical guidelines are aware of the risk of diagnosis-induced secondary malignancy due to CT imaging and some have adapted their recommendations accordingly. Results of the two ongoing trials on 738 patients are expected soon to provide more reliable results on this topic.

CONCLUSIONS

There is growing evidence that abdominopelvic MRI imaging can replace CT imaging during follow-up of patients with TC in order to reduce radiation exposure and diagnosis-induced secondary malignancy.

Management of early rectal cancer; current surgical options and future direction

Rectal cancer is the second commonest cause of cancer death within the United Kingdom. Utilization of national screening programmes have resulted in a greater proportion of patients presenting with early-stage disease. The technique of transanal endoscopic microsurgery was first described in 1984 following which further options for local excision have emerged with transanal endoscopic operation and, more recently, transanal minimally invasive surgery. Owing to the risks of local recurrence, the current role of minimally invasive techniques for local excision in the management of rectal cancer is limited to the treatment of pre-invasive disease and low risk early-stage rectal cancer (T1N0M0 disease). The roles of chemotherapy and radiotherapy for the management of early rectal cancer are yet to be fully established. However, results of high-quality research such as the GRECCAR II, TESAR and STAR-TREC randomised control trials may highlight a wider role for local excision surgery in the future, when used in combination with oncological therapies. The aim of our review is to provide an overview in the current management of early rectal cancer, the surgical options available for local excision and the future multimodal direction of early rectal cancer treatment.

Magnetic Resonance Imaging Evaluation of the Accuracy of Various Lymph Node Staging Criteria in Rectal Cancer: A Systematic Review and Meta-Analysis

Background

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.

Methods

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.

Results

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.

Conclusion

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.

Influence of incorrect staging of colorectal carcinoma on oncological outcome: are we playing safely?

Accurate preoperative staging of colorectal cancers is critical in selecting patients for neoadjuvant therapy prior to resection. Inaccurate staging, particularly understaging, may lead to involved resection margins and poor oncological outcomes. Our aim is to determine preoperative imaging accuracy of colorectal cancers compared to histopathology and define the effect of inaccurate staging on patient selection for neoadjuvant treatment(NT). Staging and treatment were determined for patients undergoing colorectal resections for adenocarcinomas in a single tertiary centre(2016-2020). Data were obtained for 948 patients. The staging was correct for both T and N stage in 19.68% of colon cancer patients. T stage was under-staged in 18.58%. At resection, 23 patients (3.36%) had involved pathological margins; only 7 of which had been predicted by pre-operative staging. However, the staging was correct for both T and N stage in 53.85% of rectal cancer patients. T stage was understaged in 26.89%. Thirteen patients had involved(R1)margins; T4 had been accurately predicted in all of these cases. There was a general trend in understaging both the tumor and lymphonodal involvement (T p < 0.00001 N p < 0.00001) causing a failure in administrating NT in 0.1% of patients with colon tumor, but not with rectal cancer. Preoperative radiological staging tended to understage both colonic and rectal cancers. In colonic tumours this may lead to a misled opportunity to treat with neoadjuvant therapy, resulting in involved margins at resection.

Characteristics of systematic reviews evaluating treatments for COVID-19 registered in PROSPERO

Characteristics and research collaboration of registered systematic reviews (SRs) on treatment modalities for coronavirus disease-2019 (COVID-19) remain unclear. This study analysed research collaboration, interventions and outcome measures in registered SRs on COVID-19 treatments and pointed out the relevant problems. PROSPERO (international prospective register of systematic reviews) was searched for SRs on COVID-19 treatments as of 2 June 2020. Excel 2016 was used for descriptive analyses of the extracted data. VOSviewer 1.6.14 software was used to generate network maps for collaborations between countries and institutions. A total of 189 SRs were included, which were registered by 301 institutions from 39 countries. China (69, 36.50%) exhibited the highest output. Cooperation between countries was not close enough. As an institution, the Chengdu University of Traditional Chinese Medicine (7, 3.70%) had the highest output. There was close cooperation between institutions. Interventions included antiviral therapy (81, 42.86%), respiratory support (16, 8.47%), circulatory support (11, 5.82%), plasma therapy for convalescent patients (11, 5.82%), immunotherapy (9, 4.76%), TCM (traditional Chinese medicine) treatment (9, 4.76%), rehabilitation treatment (5, 2.65%), anti-inflammatory treatment (16, 8.47%) and other treatments (31, 16.40%). Concerning antiviral therapy (81, 42.86%), the most commonly used antiviral agents were chloroquine/hydroxychloroquine (26, 13.76%), followed by remdesivir (12, 6.35%), lobinavir/ritonavir (11, 5.82%), favipiravir (5, 2.65%), ribavirin (5, 2.65%), interferon (5, 2.65%), abiron (4, 2.12%) and abidor (4, 2.12%). The most frequently used primary and secondary outcomes were the mortality rate (92, 48.68%) and hospital stay length (48, 25.40%), respectively. The expression of the outcomes was not standardised. Many COVID-19 SRs on treatment modalities have been registered, with a low completion rate. Although there was some collaboration between countries and institutions in the currently registered SRs on treatment modalities for COVID-19 on PROSPERO, cooperation between countries should be further enhanced. More attention should be directed towards identifying deficiencies of outcome measures, and the standardisation of results should be maximised.

A magnetic resonance imaging (MRI)-based nomogram for predicting lymph node metastasis in rectal cancer: a node-for-node comparative study of MRI and histopathology

BACKGROUND

The aim of the present study was to investigate the potential risk factors for lymph node metastasis (LNM) in rectal cancer using magnetic resonance imaging (MRI), and to construct and validate a nomogram to predict its occurrence with node-for-node histopathological validation.

METHODS

Our prediction model was developed between March 2015 and August 2016 using a prospective primary cohort (32 patients, mean age: 57.3 years) that included 324 lymph nodes (LNs) from MR images with node-for-node histopathological validation. We evaluated multiple MRI variables, and a multivariable logistic regression analysis was used to develop the predictive nomogram. The performance of the nomogram was assessed with respect to its calibration, discrimination, and clinical usefulness. The performance of the nomogram in predicting LNM was validated in an independent clinical validation cohort comprising 182 consecutive patients.

RESULTS

The predictors included in the individualized prediction nomogram were chemical shift effect (CSE), nodal border, short-axis diameter of nodes, and minimum distance to rectal cancer or rectal wall. The nomogram showed good discrimination (C-index: 0.947; 95% confidence interval: 0.920-0.974) and good calibration in the primary cohort. Decision curve analysis confirmed the clinical usefulness of the nomogram in predicting the status of each LN. For the prediction of LN status in the clinical validation cohort by readers 1 and 2, the areas under the curves using the nomogram were 0.890 and 0.841, and the areas under the curves of readers using their experience were 0.754 and 0.704, respectively. Diagnostic efficiency was significantly improved by using the nomogram (P<0.001).

CONCLUSIONS

The nomogram, which incorporates CSE, nodal location, short-axis diameter, and minimum distance to rectal cancer or rectal wall, can be conveniently applied in clinical practice to facilitate the prediction of LNM in patients with rectal cancer.

The value of different imaging methods in the diagnosis of breast cancer: A protocol for network meta-analysis of diagnostic test accuracy

BACKGROUND

: Breast cancer (BC) is the most common cancer in women all over the world and the second most common cause of cancer-related mortality. Imaging examination plays an important role in the diagnosis of early breast cancer. Due to different imaging principles and methods, all kinds of examinations have their advantages and disadvantages. It is particularly important for clinicians to choose these examination methods reasonably to achieve the best diagnostic effect. The objectives of this systematic review and NMA are to determine the diagnostic accuracy of imaging technologies for breast cancer and to compare the diagnostic accuracy of different index tests and to support guidelines development and clinical practice.

METHODS

: PubMed, Embase.com, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang, and SinoMed will be searched to identify relevant studies up to August 31, 2021. We will include random controlled trials, cross-sectional studies, case-control studies, and cohort studies that evaluate the diagnostic accuracy of different imaging diagnostic methods for breast cancer. The Quality Assessment of Diagnostic Accuracy Studies 2 quality assessment tool will be used to assess the risk of bias in each study. Standard pairwise meta-analysis and NMA will be performed using STATA V.12.0, MetaDiSc 1.40, and R 3.4.1 software to compare the diagnostic efficacy of different imaging diagnostic methods. Subgroup analyses and sensitivity analyses will be conducted to investigate the sources of heterogeneity.

RESULTS

: The results of this study will be published in a peer-reviewed journal.

CONCLUSION

: This study will comprehensively evaluate the accuracy of different imaging diagnostic methods in the diagnosis of breast cancer. The results of this study will provide high-quality evidence to support clinical practice and guidelines development.

High-resolution MRI-based radiomics analysis to predict lymph node metastasis and tumor deposits respectively in rectal cancer

PURPOSE

To establish and validate two predictive radiomics models for preoperative prediction of lymph node metastases (LNMs) and tumor deposits (TDs) respectively in rectal cancer (RC) patients.

METHODS

A total of 139 RC patients (98 in the training cohort and 41 in the validation cohort) were enrolled in the present study. High-resolution magnetic resonance images (HRMRI) were retrieved for tumor segmentation and feature extraction. HRMRI findings of RC were assessed by three experienced radiologists. Two radiomics nomograms were established by integrating the clinical risk factors, HRMRI findings and radiomics signature.

RESULTS

The predictive nomogram of LNMs showed good predictive performance (area under the curve [AUC], 0.90; 95% confidence interval [CI] 0.83-0.96) which was better than clinico-radiological (AUC, 0.83; 95% CI 0.74-0.93; Delong test, p = 0.017) or radiomics signature-only model (AUC, 0.77; 95% CI 0.67-0.86; Delong test, p = 0.003) in training cohort. Application of the nomogram in the validation cohort still exhibited good performance (AUC, 0.87; 95% CI 0.76-0.98). The accuracy, sensitivity and specificity of the combined model in predicting LNMs was 0.86,0.79 and 0.91 in training cohort and 0.83,0.85 and 0.82 in validation cohort. As for TDs, the predictive efficacy of the nomogram (AUC, 0.82; 95% CI 0.71-0.93) was not significantly higher than radiomics signature-only model (AUC, 0.80; 95% CI 0.69-0.92; Delong test, p = 0.71). Radiomics signature-only model was adopted to predict TDs with accuracy=0.76, sensitivity=0.72 and specificity=0.94 in training cohort and 0.68, 0.62 and 0.97 in validation cohort.

CONCLUSION

HRMRI-based radiomics models could be helpful for the prediction of LNMs and TDs preoperatively in RC patients.

Associating the risk of three urinary cancers with obesity and overweight: an overview with evidence mapping of systematic reviews

BACKGROUND

The relationship between cancer with overweight and obesity has been extensively reported. However, the association between urinary cancers with these risk factors remains unclear, with existing reports showing conflicting findings. The current review, therefore, sought to clarify the latter association by assessing the methodological and reporting quality of existing systematic reviews on the subject.

METHODS

We first screened PubMed, EMBASE, and Cochrane Library databases for relevant literature and subjected the resulting articles to meta-analysis. We adopted the AMSTAR-2 and PRISMA checklists for assessing methodological and reporting quality, respectively, then performed meta-analyses to determine the relationship between incidence and mortality of three types of urinary cancers with obesity and overweight. Indirect comparisons were also done across subgroups.

RESULTS

All systematic reviews (SRs) were of critically low methodological quality. Seventeen SRs had minimal reporting flaws, and 11 SRs had minor reporting flaws. We found an association between obesity with an incidence of kidney (RR = 1.68, 95% CI 1.47-1.92), bladder (RR = 1.1, 95% CI 1.07-1.13), and prostate (RR = 1.02, 95% CI 0.91, 1.13) cancers. Similarly, overweight was associated with the incidence of the three types of cancer, recording RR values of 1.37 (95% CI 1.26-1.48), 1.07 (95% CI 1.03-1.1), and 1 (95% CI 0.93, 1.07) for kidney, bladder, and prostate cancers, respectively. With regard to the dose analysis, the RR of BMI (per 5 kg/m2 increase) was associated with kidney (RR = 1.24, 95% CI 1.2-1.28), bladder (RR = 1.03, 95% CI 1.02-1.05), and prostate (RR = 1.02, 95% CI 1.01, 1.03) cancers.

CONCLUSIONS

This comprehensive quantitative analysis provides an affirmation that overweight and obesity are strong risk factors for kidney cancer, owing to a strong association between them. Conversely, a weak association between overweight and obesity with bladder and prostate cancers confirms their status as mild risk factors for the 2 types of cancer. But due to the low quality of included SRs, the results need to be interpreted with caution.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019119459.

Clinical predictors of pathological good response in locally advanced rectal cancer

Purpose

The aim of this study was to identify the clinical predictors of pathological good response (PGR) after neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC) to clarify the indications for local excision.

Methods and materials

A total of 173 patients with LARC (cT3–4/N +) who were treated with nCRT followed by surgery were enrolled in our retrospective study. Patients were categorized into two groups according to the different tumor responses of surgical pathology. Stage ypT0–1N0 was defined as the group with PGR, and stage ypT2–4N0/ypTanyN + was the defined as the pathological poor response (PPR) group, and the potential predictors were compared.

Results

Of 173 patients, PGR was achieved in 57 patients (32.95%). The distance from the inferior margin of the tumor to the anal verge, cT classification, pretreatment carcinoembryonic antigen (CEA) and the interval from the end of radiation to surgery were correlated with pathological response. In the multivariate analysis, the distance from anal verge < 5 cm (OR = 0.443, p = 0.019), pretreatment CEA < 5 ng/mL (OR = 0.412, p = 0.015) and the interval from the end of radiation to surgery ≥ 84 days (OR = 2.652, p = 0.005) were independent predictors of PGR.

Conclusions

The distance from the inferior margin of the tumor to the anal verge, pretreatment CEA and the interval from the end of radiation to surgery were significant predictors of PGR in LARC. A prospective study is needed to further validate these results in the future.

Rectal cancer: a methodological approach to matching PET/MRI to histopathology

Purpose

To enable the evaluation of locoregional disease in the on-going RECTOPET (REctal Cancer Trial on PET/MRI/CT) study; a methodology to match mesorectal imaging findings to histopathology is presented, along with initial observations.

Methods

FDG-PET/MRI examinations were performed in twenty-four consecutively included patients with rectal adenocarcinoma. In nine patients, of whom five received neoadjuvant treatment, a postoperative MRI of the surgical specimen was performed. The pathological cut-out was performed according to clinical routine with the addition of photo documentation of each slice of the surgical specimen, meticulously marking the location, size, and type of pathology of each mesorectal finding. This allowed matching individual nodal structures from preoperative MRI, via the specimen MRI, to histopathology.

Results

Preoperative MRI identified 197 mesorectal nodal structures, of which 92 (47%) could be anatomically matched to histopathology. Of the matched nodal structures identified in both MRI and histopathology, 25% were found to be malignant. These malignant structures consisted of lymph nodes (43%), tumour deposits (48%), and extramural venous invasion (9%). One hundred eleven nodal structures (55%) could not be matched anatomically. Of these, 97 (87%) were benign lymph nodes, and 14 (13%) were malignant nodal structures. Five were malignant lymph nodes, and nine were tumour deposits, all of which had a short axis diameter < 5 mm.

Conclusions

We designed a method able to anatomically match and study the characteristics of individual mesorectal nodal structures, enabling further research on the impact of each imaging modality. Initial observations suggest that small malignant nodal structures assessed as lymph nodes in MRI often comprise other forms of mesorectal tumour spread.

Trial registration

Clinical Trials Identifier:NCT03846882.

The association between body mass index and the risk of different urinary cancers: Protocol for an overview of systematic reviews

BACKGROUND

The relationship between cancer with body mass index has been extensively reported. However, association between urinary cancers with these risk factors remains unclear, with existing reports showing conflicting findings. The current review, therefore, sought to clarify the latter association by assessing the methodological and reporting quality of existing systematic reviews on the subject.

METHODS

We will screen PubMed, EMBASE, and Cochrane Library databases for relevant literature and subjected the resulting articles to meta-analysis. We will adopt the AMSTAR and PRISMA checklists for assessing methodological, and reporting quality, respectively. The association between BMI and different urinary cancers will be estimated by computing the pooled relative risk (RR) and its 95% confidence interval (CI), which will be calculated from the adjusted RR, odds ratio, or hazard ratio, and 95% CI offered in the studies. Heterogeneity between studies will be assessed with the I statistic as a measure of the proportion of total variation in estimates that is due to heterogeneity, where I values of 25%, 50%, and 75% correspond to cut-off points for low, moderate, and high degrees of heterogeneity. The random effects model will be used as the pooling method when significant heterogeneity existed and the fixed effect model will be used when no heterogeneity was observed. Possible publication bias will be tested by Begg and Egger test.

CONCLUSION

Our evidence synthesis will provide a new commentary on the current systematic review evidence for the association between BMI and the risk of different urinary cancers.

PROSPERO REGISTRATION NUMBER

CRD42019119459.

Effects of clazosentan, cilostazol, and statins on aneurysmal subarachnoid hemorrhage: A protocol for systematic review and meta-analysis

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is a disease caused by the infiltration of blood into the subarachnoid space due to the rupture of an intracranial aneurysm. It is a serious cerebrovascular disease, with a mortality rate of about 40% worldwide, which seriously threatens human life and health. Many drugs are used to treat aSAH and its complications, and some have been tested in systematic reviews and have shown good effects. But which drug has the best effect remains unclear. This network meta-analysis (NMA) aims to assess the effectiveness and feasibility of clazosentan, cilostazol, and statins in patients with aSAH.

METHODS

We will search for EMBASE.com, PubMed, the Cochrane Library, and Web of Science from inception to December 2019. Randomized controlled trials (RCTs) reporting efficacy and safety of clazosentan, cilostazol, and statins compared with the control, or compared with each other for the treatment of aSAH will be included. Two independent reviewers will assess the risk of bias of the included RCTs with the Cochrane "Risk of bias" tool. The pairwise meta-analysis will be performed with the random-effects model. The NMA will be performed in a Bayesian hierarchical framework using Markov Chain Monte Carlo method in WinBUGS 1.4.3. Egger test and funnel plot will be used to assess the publication bias. We will evaluate the quality of evidence for each outcome according to the GRADE approach.

RESULTS

The results of this NMA will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This study will summarize up-to-date evidence to compare the efficacy and safety of clazosentan, cilostazol, and statins on aSAH.PROSPERO registration number: CRD42019147523.

Comparison of the airway complications of subtypes of laryngeal mask airway and i-gel in child patients under general anaesthesia: a protocol for systematic review and network meta-analysis of randomised control trials

INTRODUCTION

Laryngeal mask airway (LMA), an alternative to traditional tracheal intubation, is widely used in clinical practice and is considered to be an effective device for airway management. LMA and i-gel have been widely used in anaesthesia and emergency situations in children. Some systematic reviews have evaluated the efficacy of LMA and i-gel in children, but they have not shown consistent results in clinical performance. This study aims to evaluate the airway complications of all subtypes of LMA and i-gel in child patients under general anaesthesia using a Bayesian network meta-analysis (NMA).

METHODS AND ANALYSIS

PubMed, EMBASE.com, the Cochrane library, Web of Science and Chinese Biomedical Literature Database will be searched from inception to January 2019. We will include prospective randomised controlled trials (RCTs) that reported the subtypes of LMA and i-gel regardless of sample size. The risk of bias assessment of the included RCTs will be conducted according to the Cochrane Handbook V.5.1.0. A Bayesian NMA will be performed using WinBUGS V.1.4.3. Grading of Recommendations Assessment, Development and Evaluation will be used to explore the quality of evidence.

ETHICS AND DISSEMINATION

Ethics approval and patient consent are not required as this study is an NMA based on published trials. The results of this NMA will be submitted to a peer-reviewed journal for publication.

PROSPERO REGISTRATION NUMBER

CRD42019127668.

Diagnostic value of seven biomarkers for breast cancer: an overview with evidence mapping and indirect comparisons of diagnostic test accuracy

Several meta-analyses have evaluated the value of biomarkers in diagnosing breast cancer, but which biomarker has the optimal diagnostic value remains unclear. This overview aimed to compare the accuracy of different biomarkers in diagnosing breast cancer. PubMed, Embase.com, the Cochrane Library of Systematic Reviews, and Web of Science were searched. The assessment of multiple systematic reviews-2 (AMSTAR-2) was used to assess the methodological quality and preferred reporting items for a systematic review and meta-analysis of diagnostic test accuracy (PRISMA-DTA) for reporting quality. Pairwise meta-analyses were performed to estimate the pooled results for each biomarker, and indirect comparisons were conducted to compare diagnostic accuracy between biomarkers. Eleven systematic reviews (SRs) involving 218 original studies were included. All SRs were of critically low methodological quality, 3 SRs had minimal reporting flaws and 8 SRs had minor flaws. The pooled sensitivity and specificity were 0.77 and 0.87 for miRNA, 0.70 and 0.87 for circulating cell-free DNA, 0.29 and 0.96 for APC gene promoter methylation, 0.69 and 0.99 for 14-3-3σ promoter methylation, 0.63 and 0.82 for CA153, 0.58 and 0.87 for CEA, and 0.73 and 0.56 for PSA. Compared with CA153 and PSA, miRNA had a higher sensitivity and specificity. The sensitivity of miRNA was higher than circulating cell-free DNA and CEA, although they had the same specificities. APC gene promoter methylation and 14-3-3σ promoter methylation were more specific than miRNA, but they had unacceptably low sensitivity. In conclusion, miRNA had better diagnostic accuracy than the other six biomarkers. But due to the low quality of included SRs, the results need to be interpreted with caution. Further study should investigate the diagnostic accuracy of different biomarkers in direct comparisons and focus on the value of combined biomarkers.

Biomarkers for detecting malignant pleural mesothelioma: Protocol for a reanalysis of published data based on systematic reviews of diagnostic test accuracy

BACKGROUND

Malignant pleural mesothelioma (MPM) is a highly invasive tumor caused primarily by asbestos exposure. In recent decades, the incidence of MPM has shown an increasing trend, posing a great threat to human health. Although there is currently no effective way to treat MPM, patients can survive for more than 5 years if the tumor is removed early. Several systematic reviews (SRs) have evaluated the diagnostic value of biomarkers for diagnosing MPM. However, no studies have been conducted to analyze the quality of these SRs and it remains unclear which biomarker is the excellent diagnostic test. This study aims to assess the methodological quality of the SRs and reanalyze the published data based on SRs to find the optimal biomarker for the early diagnosis of MPM.

METHODS

A systematic search will be performed in PubMed, Embase.com, the Cochrane Library of Systematic Reviews, and Web of Science to identify SRs reporting value of biomarkers for detecting MPM. We will evaluate the risk of bias of the included SRs according to the Assessment of Multiple Systematic Reviews-2 (AMSTAR-2) instrument. Standard pairwise meta-analysis and adjusted indirect comparison will be used to compare the diagnostic value of different biomarkers.

RESULTS

The results of this study will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This study will reanalyze the published data based on SRs to find a biomarker with the superior diagnostic performance for the diagnosis of MPM.

ETHICS AND DISSEMINATION

Ethics approval and patient consent are not required as this study is an overview based on published systematic reviews.

PROSPERO REGISTRATION NUMBER

CRD42019125880.

An overview protocol of biomarkers for breast cancer detection

BACKGROUND

Among females, breast cancer is the most commonly diagnosed cancer and the leading cause of cancer death over 100 countries. Generally, the prognosis of early-stage breast cancer is good. However, the prognosis is very poor when the disease is diagnosed at an advanced stage. Many screening methods have been used for early detection of breast cancer, but there are some limitations of these methods. Recently, some systematic reviews have evaluated the value of biomarkers for detecting breast cancer. However, most of the systematic reviews (SRs) only evaluated the diagnostic value of 1 biomarker, and it is unclear which biomarker is the best diagnostic test for breast cancer. This overview aims to assess the methodological and reporting quality of available systematic reviews and to compare the diagnostic value of different biomarkers.

METHODS

PubMed, Embase.com, the Cochrane Library of Systematic Reviews, and Web of Science were searched to identify published systematic reviews reporting the value of biomarkers for detecting breast cancer. Title and abstracts, as well as full texts, were screened in duplicate based on inclusion and exclusion criteria. The Assessment of Multiple Systematic Reviews-2 (AMSTAR-2) tool and Preferred Reporting Items for Systematic Reviews and Meta-analysis diagnostic test accuracy (PRISMA-DTA) checklist will be used to assess the methodological and reporting quality, respectively. We will conduct the pairwise meta-analysis and indirect comparisons using STATA 13.0.

RESULTS

The results of this study will be published in a peer-reviewed journal CONCLUSION:: This overview will provide comprehensive evidence of different biomarkers for the diagnosis of breast cancer.

PROSPERO REGISTRATION NUMBER

CRD42019125880.