Summary Receiver Operating Characteristic Curve Curve Research Articles

Acoustic Radiation Force Impulse Elastography for the Non-Invasive Evaluation of Hepatic Fibrosis in Non-Alcoholic Fatty Liver Disease Patients: A Systematic Review & Meta-Analysis.

BackgroundIn order to better monitor non-alcoholic fatty liver disease (NAFLD) patients at higher risk for HCC, there is a need for non-invasive diagnostic approaches to screen for the presence of advanced fibrosis in these patients. The aim of this systematic review and meta-analysis will be to evaluate the diagnostic efficacy of ARFI elastography in detecting hepatic fibrosis in NAFLD patients.MethodsRelevant studies were identified from systematic searches of several major electronic databases (PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials). The primary outcomes were the summary sensitivity, summary specificity, the diagnostic odds ratio, and the summary receiver operating characteristic curve (SROC) of ARFI elastography in detecting significant fibrosis (defined as 4>F≥2) in NAFLD patients. Study quality was assessed using the Quality Assessment of Studies of Diagnostic Accuracy included in Systematic Review (QUADAS-2).ResultsThe summary sensitivity and specificity of ARFI in detecting significant fibrosis were 80.2% (95% confidence interval (CI): 0.758–0.842; p = 0.0000) and 85.2% (95% CI: 0.808–0.890), p = 0.1617), respectively. The pooled diagnostic odds ratio of ARFI in detecting significant fibrosis was 30.13 (95% CI: 12.08–75; chi-squared = 14.59, p = 0.0237). The area under the SROC curve (AUC) was 0.898 (standard error (SE): 0.031) with a Q* index of 0.830 (SE: 0.033).ConclusionsARFI elastography appears to be modestly accurate in detecting significant fibrosis in NAFLD patients. Future studies in this field should provide head-to-head comparisons of ARFI elastography versus other elastographic imaging modalities in NAFLD patients.

MicroRNAs as novel biomarkers for the differentiation of malignant versus benign thyroid lesions: a meta-analysis.

The aim of this meta-analysis was to systematically evaluate the diagnostic accuracy of microRNAs (miRNAs) in distinguishing malignant thyroid lesions from benign ones and to determine the potential of miRNAs as diagnostic biomarkers for thyroid cancer. The random-effect model was used to summarize the pooled estimates of diagnostic accuracy, including sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR). The summary receiver-operating characteristic curve (SROC) and area under the SROC curve (AUC) were used to further evaluate the overall diagnostic value. Overall, 20 studies from 7 articles, including 266 thyroid cancer patients and 277 controls with benign thyroid disease, were available for analysis. The pooled sensitivity, specificity, PLR, NLR, and DOR were: 0.78 (95%CI = 0.74-0.81), 0.73 (95%CI = 0.69-0.77), 3.17 (95%CI = 2.28-4.40), 0.30 (95%CI = 0.23-0.39), and 12.6 (95%CI = 8.26-19.4), respectively, and the AUC value was 0.85. The multiple miRNA assay yielded better diagnostic performance than the single miRNA assay, with sensitivity of 0.90 versus 0.75, specificity of 0.86 versus 0.71, PLR of 6.14 versus 2.71, NLR of 0.13 versus 0.36, DOR of 44.5 versus 8.81, and AUC of 0.95 versus 0.82, suggesting that the multiple miRNA assay is a more credible method for thyroid cancer detection. In summary, miRNA assays, especially multiple miRNA assays, may play an important role as a second-line diagnostic tool to improve the diagnostic accuracy of fine needle aspiration biopsy in indeterminate lesions. However, further studies are warranted to confirm our findings.

Predictive accuracy of amyloid imaging for progression from mild cognitive impairment to Alzheimer disease with different lengths of follow-up: a meta-analysis. [Corrected

In the past decade, amyloid deposition has been shown to begin many years before the clinical symptoms of dementia in mild cognitive impairment (MCI) due to Alzheimer disease (AD). Longitudinal studies with different follow-up durations have suggested that C-Pittsburgh compound B positron emission tomography (C-PIB-PET) may play a role in stratifying patients with MCI into risk levels for developing AD. However, the predictive accuracy of amyloid imaging for the progression from MCI to AD with different follow-up durations has not yet been systematically evaluated. A formal systematic evaluation of the sensitivity, specificity, and other properties of C-PIB-PET was performed.This study aimed to systematically review and meta-analyze published data on the diagnostic performance of C-PIB-PET for predicting conversion to AD in patients with MCI and to determine whether long-term follow-up has a positive effect on predictive accuracy. Relevant studies were systematically identified through electronic searches, which were performed in MEDLINE (OvidSP), EMBASE (OvidSP), BIOSIS Previews (ISI Web of Knowledge), Science Citation Index (ISI Web of Knowledge), PsycINFO (Ovid SP), and LILACS (Bireme). The methodological quality of each study was assessed by QUADAS-2. Sensitivities and specificities of C-PIB-PET in individual studies were calculated, and the studies underwent meta-analysis with a random-effects model. A summary receiver-operating characteristic curve (SROC) was constructed with the Moses-Shapiro-Littenberg method. Pooled estimates of sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), diagnostic odds ratio (DOR), and the SROC curve of each subgroup were determined. Heterogeneity was tested, and potential sources for heterogeneity were explored by assessing whether certain covariates significantly influenced the relative DOR.Eleven eligible studies consisting of a total of 352 patients with MCI at baseline were included. Overall, the studies were of moderate-to-high methodological quality. The sensitivity and specificity of C-PIB-PET for predicting conversion to AD ranged from 83.3% to 100% and 41.1% to 100%, respectively, with pooled estimates of 94.7% (95% confidence interval [CI]: 89.8%-97.7%) and 57.2% (95% CI: 50.1%-64.2%), respectively . Moderate heterogeneity was observed for specificity between the included studies (I = 42.1%). The pooled estimates for the long-term follow-up subgroup were 95.5% sensitivity (95% CI: 84.5%-99.4%) and 72.4% specificity (95% CI: 59.1%-83.3.8%), whereas the pooled estimates for the short-term follow-up subgroup were 94.4% sensitivity (95% CI: 88.2%-97.9%) and 51.0% specificity (95% CI: 42.6%-59.5%). Homogeneity in each subgroup was significantly higher than that of the included studies, and most diagnostic indicators in the long-term follow-up subgroup were far superior to those in the short-term follow-up subgroup or the entire group. Not all of the methodological quality scores of studies included in this systematic review were high. Current evidence suggests that prolongation of the follow-up duration tended to yield greater accuracy of C-PIB-PET for predicting the progression from MCI to AD. In particular, the specificity, which reflects the exploratory nature of the use of amyloid imaging to identify the process of MCI to AD, was improved with a longer follow-up period.

Diagnostic Accuracy of Galectin‐3 for Well‐Differentiated Thyroid Cancer on Fine‐Needle Aspiration: A Meta‐analysis

Objectives: (1) Examine and meta-analyze the literature on galectin-3 staining on fine-needle aspiration (FNA) samples of thyroid nodules. (2) Summarize the diagnostic test accuracy of galectin-3 staining on FNA for well-differentiated thyroid cancer (WDTC). Methods: A systematic review of studies from 1990 to 2014 examining the diagnostic test properties of galectin-3 on thyroid nodule samples obtained by FNA with regard to WDTC. Data were meta-analyzed using DerSimonian-Laird random effect models for data pooling. Studies were weighted by inverse variance, and between-study variance was estimated using the Empirical Bayes method. Study heterogeneity and threshold effects were analyzed using the Cochrane Q and Spearman correlation coefficient, respectively. Results: Sixteen studies with 2076 cases were identified. The pooled sensitivity of galectin-3 for WDTC was 89.4% [confidence interval (CI): 87.2-91.4], and specificity was 91.9% (CI: 90.2-93.4). The positive likelihood ratio was 10.05 (CI: 8.24-12.26), and negative likelihood ratio was 0.12 (CI: 0.10-0.15). The diagnostic odds ratio of a positive galectin-3 stain on FNA was 71.3 (CI: 52.7-96.5). The area under the curve for the summary receiver operating characteristics curve (SROC) was 95.3% (standard error: 0.5%). Conclusions: The current study shows galectin-3 staining of preoperative thyroid nodule FNA samples to be a test with strong diagnostic accuracy for WDTC, as seen by its favorable sensitivity, specificity, diagnostic odds ratio, and SROC curve. This supports its role as a useful adjunct in the preoperative workup of thyroid nodules.

Fluorescence-guided resection of high-grade gliomas: A systematic review and meta-analysis

The present systematic review and meta-analysis was to analyze of the advantages of intraoperative fluorescence-guided resection of high-grade gliomas. Systematic computerized searches of the PubMed and Web of Knowledge were performed. The outcomes included diagnostic value for identification of tumor tissue, gross total resection, and prognosis. The summary receiver operating characteristic curves (SROC), the pooled sensitivities, the pooled specificities, the pooled odd ratio (OR) and the pooled hazard ratio (HR) were estimated by meta-analysis. Twelve studies were included. The pooled sensitivity and the pooled specificity for identification of tumor tissue was 0.84 (95% CI: 0.81-0.87), and 0.91 (95% CI: 0.87-0.94), respectively. And the overall weighted AUC of the SROC curve was 0.9520 ± 0.0116. The summary OR of the gross total resection rate in patients with fluorescein-guided resection compared with patients with no fluorescein was 4.372 (95% CI 2.937-6.508). Fluorescein-guided resection was associated with a reduced risk of progression-free survival compared with no fluorescein, with HR 0.73 (95% CI 0.57-0.94, P = 0.01). The pooled HR of overall survival was 1.000 (95% CI 0.960-1.040) between two groups. No significant publication bias was found. Fluorescence-guided resection of high-grade gliomas is effective for diagnosing tumor margins, increasing gross total resection, and reducing the risk of progression-free survival. But this conclusion should be confirmed by large sample randomized controlled clinical trials.

Uso Combinado del Método Cualitativo y del Metanálisis en el Enfoque Diagnóstico de la Diarrea Infecciosa

Objetivo: Comparar la utilidad diagnóstica de pruebas índice en la identificación de la diarrea invasiva. Métodos: Combinación de análisis cualitativo y cuantitativo (metanálisis). Identificación de datos y selección de los estudios: De 2603 referencias identificadas vía MEDLINE (1970 -1994), listas de referencia y por correspondencia con expertos en el campo, 81 cumplieron los requerimientos de selección preestablecidos. De éstas, 25 contenían datos suficientes para un metanálisis adicional. Extracción de datos: En la revisión cualitativa, un autor extrajo información amplia sobre la utilidad diagnóstica de las pruebas índice y sobre las características metodológicas de los estudios. En el metanálisis, todos los datos de los artículos seleccionados fueron extraídos por un investigador, en tanto otro verificó su exactitud. Se calculó la tasa de verdaderos positivos (TPR) y de falsos positivos (FPR), a partir de cada tabia de contingencia de 2 x 2. Utilizando el método de transformación logística y regresión lineal ponderada de cuadrados mínimos, se elaboró curvas resumen de las característícas operativas del receptor (SROC), para determinar la utilidad diagnóstica comparativa de las pruebas. Resultados del análisis de datos: El enfoque cualitativo no restrictivo identificó problemas metodológicos que fueron evaluados adicionalmente en el estudio cuantitativo. En el metanálisis, la graficación de TPR contra FPR, como curvas SROC, demostró puntos dispersos, indicando heterogeneidad. La curva de lactoferrina fecal mostró el mayor rendimiento y la de leucocitos fecales el menor rendimiento. Conclusiones: La lactoferrina fecal es la prueba con mayor utilidad diagnóstica en la identificación de la diarrea invasiva. Se propone la utilización del enfoque combinado cualitativo y metanalítico como un método adecuado de evaluación de la utilidad de pruebas diagnósticas, tanto en la práctica clínica como en el proceso general de análisis de decisiones.

Diagnostic Performance of Des-γ-carboxy Prothrombin for Hepatocellular Carcinoma: A Meta-Analysis.

Background. There have been many reports on des-γ-carboxy prothrombin (DCP) as a promising serum marker in the diagnosis of hepatocellular carcinoma (HCC); however, the results are inconsistent and even conflicting. Methods. This meta-analysis was performed to investigate the performance of DCP in the diagnosis of HCC. Following a systematic review of relevant studies, Meta-DiSc 1.4 software was used to extract data and to calculate the overall sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR). Data are presented as forest plots and summary receiver operating characteristic curve (SROC) analysis was used to summarize the overall test performance. Results. Twelve studies were included in our meta-analysis. The overall sensitivity, specificity, PLR, and NLR of DCP for the detection of HCC in the studies included were 71% (95%CI: 68%–73%), 84% (95%CI: 83%–86%), 6.48 (95%CI: 4.22–9.93), and 0.33 (95%CI: 0.25–0.43), respectively. The area under the SROC curve was 0.8930 and the Q index was 0.8238. Significant heterogeneity was found. Conclusion. This meta-analysis indicated that DCP had moderate diagnostic accuracy in HCC. Further studies with rigorous design, large sample size, and mmultiregional cooperation are needed in the future.

Potential Role of microRNA-21 in the Diagnosis of Gastric Cancer: A Meta-Analysis

IntroductionAccumulating evidences indicate that microRNA-21(miR-21) show significant high concentration in plasma of gastric cancer (GC) patients compared to normal individuals, suggesting that it may be a useful novel diagnostic biomarker for gastric cancer. Therefore, we aimed to assess the potential diagnostic value of miR-21 for gastric cancer in this study.MethodsLiterature database including PubMed, Embase, the Cochrane Library, Web of Science, Ovid, SciVerse, Science Direct, Scopus, BioMed Central, Biosis previews,Chinese Biomedical Literature Database (CBM), Chinese National Knowledge Infrastructure (CNKI), Technology of Chongqing (VIP), and Wan Fang DATA were searched for publications concerning the diagnostic value of miR-21 for GC without language restriction. The quality of each study was scored with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS). Then, data were retrieved from any qualified article hits and subject to meta-analysis. Receiver operating characteristic curves (ROC) were used to check the overall test performance. Evidence of heterogeneity was evaluated using the Chi-square and I 2 test.ResultsFive studies with a total 251 GC patients and 184 control individuals were included in this meta-analysis. All of the included studies are of high quality (QUADAS score$13). The summary estimates revealed that the pooled sensitivity is 66.5% (95% confidence interval (CI): 55.0%–76.3%) and the specificity is 83.1% (95% CI: 69.4%–91.5%). In addition, the area under the summary ROC curve (AUC) is 0.80.ConclusionThe current evidence suggests that miR-21 has potential diagnostic value with a moderate sensitivity and specificity for GC. More prospective studies on the diagnostic value of miR-21 for GC are needed in the future.

Pyrosequencing for the rapid detection of rifampicin resistance in <I>Mycobacterium tuberculosis</I>: a meta-analysis [Review article

Multidrug-resistant tuberculosis is a major threat to the control of tuberculosis and to public health. Whereas most conventional methods of drug susceptibility testing (DST) are precise but time consuming, pyrosequencing is a rapid, high-throughput technique. To conduct a meta-analysis to evaluate the overall accuracy of pyrosequencing for the detection of rifampicin (RMP) resistance. We searched PubMed, Web of Science, Elsevier and BIOSIS databases according to a written protocol and explicit study selection criteria. A summary receiver operating characteristic curve (SROC) and Cochrane (Q*) index were calculated to perform this meta-analysis using Meta-Disc software. Twelve studies involving 594 specimens with RMP resistance and 793 RMP-susceptible specimens met the inclusion criteria. Of these, 11 were based on Mycobacterium tuberculosis clinical isolates. The overall sensitivity and specificity were estimated at respectively 0.94 (95%CI 0.92-0.96) and 0.98 (95%CI 0.97-0.99). The area under the SROC curve was 0.99 and the Cochrane (Q*) index was 0.96. For clinical specimens, the overall sensitivity and specificity estimates were respectively 0.89 (range 0.52-1.00) and 0.99 (range 0.95-1.00). This meta-analysis shows that pyrosequencing is a highly sensitive and specific tool for the detection of RMP resistance in M. tuberculosis. The pyrosequencing assay is conducted in a high-throughput format, with a turnaround time of <2 h, making it substantially faster than conventional DST methods. We propose that pyrosequencing applied directly to clinical specimens instead of M. tuberculosis isolates could be of greater clinical value.

Bayesian meta-analysis for test accuracy

Bayesian meta-analysis for test accuracy Lyle D BroemelingBroemeling &amp; Associates Inc, Medical Lake, WA, USAAbstract: Determining the accuracy of a medical test is quite difficult because accuracy is an elusive parameter to estimate. A common scenario is estimating the true and false positive fractions from different studies and arriving at a common value of the accuracy of the test. The accuracy is expressed with an estimate similar to the area under the receiver operating characteristic (ROC) curve. Under the assumption that the ROC area is the same across all tests, the true and false positive fractions can be plotted on the same graph to obtain an experimental ROC curve, called the summary ROC curve (SROC) curve. The estimate of the accuracy of the curve is the ordinate of the point of intersection, where the SROC curve intersects the line with equation true positive rate + false positive rate = 1. Using a Bayesian approach, the presentation begins with summarizing information about test accuracy for tests with ordinal and continuous scores, where it is assumed the tests share a common ROC curve, but the tests may differ in the threshold used to declare a positive test. The true and false positive rates are transformed so that one may use bilogistic regression to determine the accuracy of the combined tests where the posterior distribution of the parameters of the model are determined. Bayesian inferences are based on the posterior distribution of the SROC curve and the computations are executed with the WinBUGS software package, and several examples from various areas of medicine illustrate the methodology.Keywords: Bayesian inferences, meta-analysis, SROC curve

Diagnostic precision of carcinoembryonic antigen in the detection of recurrence of colorectal cancer

The aim of the study was to evaluate the diagnostic precision of serum carcinoembryonic antigen (CEA) in the detection of local or distant recurrence following resectional surgery for colon and rectal cancer. Quantitative meta-analysis was performed on 20 studies, comparing serum CEA with radiological imaging and/or pathology in detecting colorectal cancer (CRC) recurrence in 4285 patients. The cut-off for a 'positive' CEA ranged from 3 to 15 ng/ml between the various studies. Sensitivity, specificity and diagnostic odds ratio (DOR) were calculated for each study. Summary receiver operating characteristic curves (SROC) and sub-group analysis were undertaken. The overall sensitivity and specificity of CEA for detecting CRC recurrence was 0.64 (95% CI: 0.61-0.67) and 0.90 (95% CI: 0.89-0.91), respectively. The area under the SROC curve was 0.75 (SE=0.04) and the diagnostic odds ratio was 18.44 (95% CI: 11.94-28.49). A CEA cut-off of 5 ng/ml yielded a higher diagnostic odds ratio than a cut-off of 3 ng/ml (15.5 vs. 11.1). Using meta-regression analysis the optimum CEA cut-off point for the best combination of sensitivity and specificity was 2.2 ng/ml. On sub-group analysis high quality studies, and those involving > or =100 patients yielded a marginal improvement in the sensitivity and specificity with minimal change to the SROC. Serum CEA is a test with high specificity but insufficient sensitivity for detecting CRC recurrence in isolation. A cut-off of 2.2 ng/ml may provide an ideal balance of sensitivity and specificity. It may be useful as a first-line surveillance investigation in patients during surgical follow-up based on serial CEA measurements using temporal trends in conjunction with clinical, radiological and/or histological confirmation.

Diagnostic precision of endoanal MRI in the detection of anal sphincter pathology—a meta-analysis

This study aims to evaluate the diagnostic precision of endoanal magnetic resonance imaging in identifying anal sphincter injury and/or atrophy when compared with either endoanal ultrasound or surgical diagnosis. Quantitative meta-analysis was performed on nine studies, comparing endoanal MRI with endoanal ultrasound or surgical diagnosis in 157 patients. Sensitivity, specificity, and diagnostic odds ratio were calculated for each study. Summary receiver operating characteristic curves (SROC) and subgroup analysis were undertaken. The overall sensitivity and specificity of endoanal MRI for external sphincter injury was 0.78 (95%CI: 0.66-0.84) and 0.66 (95%CI: 0.51-0.79), respectively. For internal sphincter injury detection, this was 0.63 (95%CI: 0.50-0.74) and 0.71 (95%CI: 0.60-0.81), respectively. For detection of atrophy, this was 0.86 (95%CI: 0.71-0.95) and 0.82 (95%CI: 0.65-0.93), respectively. The area under the SROC curve and diagnostic odds ratio were 0.84 (SE = 0.07) and 6.14 (95%CI: 2.17-17.4) for external sphincter injury, 0.79 (SE = 0.07) and 4.60 (95%CI: 1.75-12.15) for internal sphincter injury, and 0.92 (SE = 0.08) and 21.49 (95%CI: 2.87-160.64) for sphincter atrophy. Endoanal MRI was sensitive and specific for the detection of external sphincter injury and especially sphincter atrophy. It may be useful as an alternative to endoanal ultrasound in patients presenting with fecal incontinence, although further clinical studies are needed to identify its best application in clinical practice.

Meta-analysis of sentinel lymph node biopsy following preoperative chemotherapy in patients with operable breast cancer

561 Background: Preoperative chemotherapy is being utilized more frequently in patients with early-stage breast cancer. The utility of sentinel lymph node biopsy (SNB) following preoperative chemotherapy is yet to be determined. Methods: A systematic review was conducted through sensitive electronic searches of MEDLINE, Cancerlit, ASCO Proceedings and the Cochrane Collaborative Research Database. Completion axillary lymph node dissection was an inclusion criteria for the analysis. Diagnostic test characteristics were calculated based on pooled data. A meta-analysis was performed using weighted average to calculate the sensitivity of SNB and associated 95% confidence intervals (95% CI). A summary receiver operating characteristic curve (SROC) was constructed using S-Plus robust resistant regression methods to assess test performance. Results: Twelve studies were identified; 11 reported favorable results. The sentinel lymph node was successfully identified in 84% to 98% of patients. The range for reported false negative (FN) rate was 0–20%. The specificity (true negative rate) was reported as 100% in all studies. The identification rate (IR) in studies which utilized combination dye and radioisotope techniques for SNB was higher than in studies using non-standardized (dye or isotope) approaches (91% vs 86%). Pooling of data resulted in an overall IR of 87% with a sensitivity (true positive (TP)/ TP+FN), positive predictive value and overall accuracy of 90%, 100% and 95.2%, respectively. The adjusted parameters revealed a global sensitivity of 89% (95% CI, 0.86–0.93). The area under the SROC curve was 0.98 indicating that SNB following preoperative chemotherapy has outstanding discrimination. Conclusions: The published literature supports the use of SNB for assessment of the axilla in patients with clinically node negative disease following preoperative chemotherapy. Both dye and radioisotope methods should be used to maximize the IR. Meta-analysis demonstrates that the sensitivity of SNB in this clinical scenario is similar to that of patients who have not received preoperative chemotherapy. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration British Journal of Surgery Research Bursaries

Sentinel node biopsy as a practical alternative to axillary lymph node dissection in breast cancer patients: An approach to its validity

Sentinel node biopsy (SNB) has been proposed as an alternative to axillary lymph-node dissection (ALND) in breast cancer. Before implementing SNB in our practice, we wished to test its validity by comparing it to the standard ALND, both in our hands and with other reported series. One hundred thirty-two patients were included prospectively. SNB and immediate ALND were performed. For SNB, a technetium-colloid was used to produce preoperative lymphoscintigraphy and intraoperative gamma-probe search for the SN. Serial sectioning and immunostains were used on the SN. A comprehensive review of the literature was done in order to run a meta-analysis of diagnostic tests using a summary receiver operating characteristic curve (SROC) to calculate the pooled parameters of sensitivity and associated 95% confidence interval (95% CI), including our own data. Our technical success rate was 96%. Local sensitivity was 96%, with a 95% CI from 85%-99%. Seven patients were upstaged by the SNB. A literature search identified 18 studies published from 1996-1999. Estimates of sensitivity ranged from 83%-100%. The pooled data meta-analysis gave a global sensitivity of 91%, with a 95% CI from 89%-93%. The area under the global SROC curve was 0.9967. The minimally invasive SNB was shown to be a practical alternative to ALND. We propose to use local as well as global sensitivity and associated 95% CI to test the validity of SNB in the clinical setting. Due to limitations of ALND as the golden standard, SNB can in fact be considered a more accurate method for nodal staging.