Identification and staging of pancreatic tumours using computed tomography, endoscopic ultrasound and mangafodipir trisodium-enhanced magnetic resonance imaging

The diagnostic accuracy of endoscopic ultrasound vs. contrast-enhanced computed tomography in local staging of pancreatic adenocarcinoma: a bi-national multicenter study

BACKGROUND

Identification of pancreatic cancer (PC) local invasion is crucial to optimize patients' selection for surgery.

AIMS

To determine the diagnostic accuracy of contrast-enhanced computed tomography (CECT) and endoscopic ultrasound (EUS) in local staging of PC.

METHODS

We performed a multicenter study including all patients with PC who underwent surgery.

RESULTS

One hundred twelve patients were included. Surgical findings of peri-pancreatic lymph nodes (LN), vascular and adjacent organ involvement were seen in 67 (59.8%), 33 (29.5%) and 19 patients (17%), respectively. The diagnostic performance of EUS was better than CECT in peri-pancreatic LN. The sensitivity, specificity, positive predictive value (PPV) and negative predictive (NPV) of CECT vs. EUS were 28.4%, 80%, 67.9% and 42.9% vs. 70.2%, 75.6%, 81% and 63%, respectively. For vascular and adjacent organ involvement, the sensitivity, specificity, PPV and NPV were 45.5%, 93.7%, 75%, 80.4% and 31.6%, 89.2%, 37.5% and 86.5% for CECT, respectively, vs. 63.6%, 93.7%, 80.8%, 86.1% and 36.8%, 94.6%, 58.3% and 88% for EUS, respectively. Combining both CECT and EUS, the sensitivity for peri-pancreatic LN, vascular and adjacent organ involvement improved (76.1%, 78.8% and 42%), respectively.

CONCLUSION

EUS was superior to CECT in local staging. Combined EUS and CECT had a higher sensitivity than either alone.

Optimal value of CA19-9 determined by KRAS-mutated circulating tumor DNA contributes to the prediction of prognosis in pancreatic cancer patients

Despite the acceptance of carbohydrate antigen 19-9 (CA19-9) as a valuable predictor for the prognosis of pancreatic ductal adenocarcinoma (PDAC), its cutoff value remains controversial. Our previous study showed a significant correlation between CA19-9 levels and the presence of KRAS-mutated ctDNA in the blood of patients with PDAC. Based on this correlation, we investigated the optimal cutoff value of CA19-9 before surgery. Continuous CA19-9 values and KRAS-mutated ctDNAs were monitored in 22 patients with unresectable PDAC who underwent chemotherapy between 2015 and 2017. Receiver operating characteristic curve analysis identified 949.7 U/mL of CA19-9 as the cutoff value corresponding to the presence of KRAS-mutated ctDNA. The median value of CA19-9 was 221.1 U/mL. Subsequently, these values were verified for their prognostic values of recurrence-free survival (RFS) and overall survival (OS) in 60 patients who underwent surgery between 2005 and 2013. Multivariate analysis revealed that 949.7 U/mL of CA19-9 was an independent risk factor for OS and RFS in these patients (P = 0.001 and P = 0.010, respectively), along with lymph node metastasis (P = 0.008 and P = 0.017), unlike the median CA19-9 level (P = 0.150 and P = 0.210). The optimal CA19-9 level contributes to the prediction of prognosis in patients with PDAC before surgery.

Endoscopic ultrasound versus computed tomography in determining the resectability of pancreatic cancer: A diagnostic test accuracy meta-analysis

BACKGROUND/AIM

Endoscopic ultrasound (EUS) and contrast-enhanced computed tomography (CT) with pancreas protocol are used in assessing the resectability of neoplastic pancreatic lesions. Here, we performed a diagnostic test accuracy (DTA) meta-analysis, comparing the diagnostic accuracy of EUS and CT in evaluating the resectability of pancreatic cancer using surgical assessment as the reference standard.

PATIENTS AND METHODS

A comprehensive electronic search was conducted up to March 2020. Studies comparing EUS and CT in assessing the resectability of pancreatic cancer using surgical assessment as reference standard were included. QUADAS-2 tool was used to assess the quality of the included studies. After data extraction, an analysis was done using DerSimonian Laird method (random-effects model) to estimate the overall diagnostic odds ratio (DOR) and determine the best-fitting receiver operating characteristics (ROC) curve.

RESULTS

Two studies, with 77 subjects combined, were included in the analysis. Overall, the risk of bias was moderate. EUS and CT were comparable in determining the resectability of pancreatic cancer with AUC = 75% (95% confidence interval (CI) 66%- 84%) for EUS as compared to 78% (95% CI 69%- 87%) for CT (P > 0.05). Pooled sensitivity and specificity was 87% (95% CI 70%- 96%) and 63% (95% CI 48%- 77%), respectively for EUS and 87% (95% CI 70%- 96%) and 70% (95% CI 55%- 83%), respectively for CT. DOR was 11.51 (95% CI 3.55- 36.81) for EUS as compared to 15.91 (95% CI 4.83- 51.62) for CT (P > 0.05).

CONCLUSIONS

Both EUS and CT provide reasonable sensitivity and specificity to detect the resectability of pancreatic cancer.

Endoscopic ultrasonography for pancreatic solid lesions

The incidence and mortality rates of pancreatic cancer, which has a poor prognosis, are rising rapidly. Endoscopic ultrasonography (EUS) provides superior spatial resolution compared with other imaging modalities such as transabdominal ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), and it is considered among the most reliable and efficient diagnostic modalities for pancreatic diseases. In this review, we show that EUS is useful for detection of pancreatic solid lesions and staging of pancreatic cancer. EUS also plays an important role in screening patients with high-risk factors for pancreatic cancer. Although EUS is useful for detection of small pancreatic lesions, pancreatic lesions are difficult to characterize using this modality, because most pancreatic solid lesions appear hypoechoic on EUS. From this point of view, contrast-enhanced harmonic EUS (CH-EUS) plays an important role in the differential diagnosis of pancreatic lesions. EUS and CH-EUS are also useful for staging pancreatic cancer. Moreover, EUS-guided fine-needle aspiration (EUS-FNA) is superior to other modalities in terms of cytopathological diagnosis. Although EUS-FNA has a high diagnostic ability for pancreatic cancer, the combination of EUS-FNA and CH-EUS improves the diagnostic ability by decreasing the number of false-negative cases. Thus, conventional EUS, EUS-FNA, and CH-EUS are essential in clinical practice for the diagnosis of pancreatic solid lesions.

Impact of endoscopic ultrasonography on diagnosis of pancreatic cancer

Accumulated evidence has revealed that endoscopic ultrasonography (EUS) has had a great impact on the clinical evaluation of pancreatic cancers. EUS can provide high-resolution images of the pancreas with a quality regarded as far surpassing that achieved on transabdominal ultrasound (US), computed tomography (CT), or magnetic resonance imaging (MRI). EUS is particularly useful for the detection of small pancreatic lesions, while EUS and its related techniques such as contrast-enhanced EUS (CE-EUS), EUS elastography, and EUS-guided fine needle aspiration (EUS-FNA) are also useful in the differential diagnosis of solid or cystic pancreatic lesions and the staging (T-staging, N-staging, and M-staging) of pancreatic cancers. In the diagnosis of pancreatic lesions, CE-EUS and EUS elastography play a complementary role to conventional EUS. When sampling is performed using EUS-FNA, CE-EUS and EUS elastography provide information on the target lesions. Thus, conventional EUS, CE-EUS, EUS elastography, and EUS-FNA are essential in the clinical investigation of pancreatic cancer.

Role of Endoscopic Ultrasonography and Endoscopic Retrograde Cholangiopancreatography in the Clinical Assessment of Pancreatic Neoplasms

Accurate diagnosis and staging of pancreatic neoplasms is essential for surgical planning and identification of locally advanced and metastatic disease that is incurable by surgery. The ability to position the endoscopic ultrasonography (EUS) transducer close to the pancreas combined with the use of fine-needle aspiration enables the accurate diagnosis of pancreatic cysts and solid masses. EUS is also increasingly being used to procure core tissue for molecular analysis that facilitates personalized treatment of pancreatic cancer. Various therapeutic interventions can be undertaken under EUS guidance. This article focuses on the applications of EUS and endoscopic retrograde cholangiopancreatography in pancreatic neoplasms.

Diagnostic accuracy of different imaging modalities following computed tomography (CT) scanning for assessing the resectability with curative intent in pancreatic and periampullary cancer

BACKGROUND

Periampullary cancer includes cancer of the head and neck of the pancreas, cancer of the distal end of the bile duct, cancer of the ampulla of Vater, and cancer of the second part of the duodenum. Surgical resection is the only established potentially curative treatment for pancreatic and periampullary cancer. A considerable proportion of patients undergo unnecessary laparotomy because of underestimation of the extent of the cancer on computed tomography (CT) scanning. Other imaging methods such as magnetic resonance imaging (MRI), positron emission tomography (PET), PET-CT, and endoscopic ultrasound (EUS) have been used to detect local invasion or distant metastases not visualised on CT scanning which could prevent unnecessary laparotomy. No systematic review or meta-analysis has examined the role of different imaging modalities in assessing the resectability with curative intent in patients with pancreatic and periampullary cancer.

OBJECTIVES

To determine the diagnostic accuracy of MRI, PET scan, and EUS performed as an add-on test or PET-CT as a replacement test to CT scanning in detecting curative resectability in pancreatic and periampullary cancer.

SEARCH METHODS

We searched MEDLINE, Embase, Science Citation Index Expanded, and Health Technology Assessment (HTA) databases up to 5 November 2015. Two review authors independently screened the references and selected the studies for inclusion. We also searched for articles related to the included studies by performing the "related search" function in MEDLINE (OvidSP) and Embase (OvidSP) and a "citing reference" search (by searching the articles that cite the included articles).

SELECTION CRITERIA

We included diagnostic accuracy studies of MRI, PET scan, PET-CT, and EUS in patients with potentially resectable pancreatic and periampullary cancer on CT scan. We accepted any criteria of resectability used in the studies. We included studies irrespective of language, publication status, or study design (prospective or retrospective). We excluded case-control studies.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed data extraction and quality assessment using the QUADAS-2 (quality assessment of diagnostic accuracy studies - 2) tool. Although we planned to use bivariate methods for analysis of sensitivities and specificities, we were able to fit only the univariate fixed-effect models for both sensitivity and specificity because of the paucity of data. We calculated the probability of unresectability in patients who had a positive index test (post-test probability of unresectability in people with a positive test result) and in those with negative index test (post-test probability of unresectability in people with a positive test result) using the mean probability of unresectability (pre-test probability) from the included studies and the positive and negative likelihood ratios derived from the model. The difference between the pre-test and post-test probabilities gave the overall added value of the index test compared to the standard practice of CT scan staging alone.

MAIN RESULTS

Only two studies (34 participants) met the inclusion criteria of this systematic review. Both studies evaluated the diagnostic test accuracy of EUS in assessing the resectability with curative intent in pancreatic cancers. There was low concerns about applicability for most domains in both studies. The overall risk of bias was low in one study and unclear or high in the second study. The mean probability of unresectable disease after CT scan across studies was 60.5% (that is 61 out of 100 patients who had resectable cancer after CT scan had unresectable disease on laparotomy). The summary estimate of sensitivity of EUS for unresectability was 0.87 (95% confidence interval (CI) 0.54 to 0.97) and the summary estimate of specificity for unresectability was 0.80 (95% CI 0.40 to 0.96). The positive likelihood ratio and negative likelihood ratio were 4.3 (95% CI 1.0 to 18.6) and 0.2 (95% CI 0.0 to 0.8) respectively. At the mean pre-test probability of 60.5%, the post-test probability of unresectable disease for people with a positive EUS (EUS indicating unresectability) was 86.9% (95% CI 60.9% to 96.6%) and the post-test probability of unresectable disease for people with a negative EUS (EUS indicating resectability) was 20.0% (5.1% to 53.7%). This means that 13% of people (95% CI 3% to 39%) with positive EUS have potentially resectable cancer and 20% (5% to 53%) of people with negative EUS have unresectable cancer.

AUTHORS' CONCLUSIONS

Based on two small studies, there is significant uncertainty in the utility of EUS in people with pancreatic cancer found to have resectable disease on CT scan. No studies have assessed the utility of EUS in people with periampullary cancer.There is no evidence to suggest that it should be performed routinely in people with pancreatic cancer or periampullary cancer found to have resectable disease on CT scan.

Imaging of the Pancreas

The evaluation of pancreatic lesions, from solid pancreatic masses to pancreatic cysts, remains a clinical challenge. Although cross-sectional imaging remains the cornerstone of the initial evaluation of an indeterminate pancreatic lesion, advances in imaging with the advent of endoscopic ultrasound scan, elastography, contrast-enhanced endoscopic ultrasound scan, and probe-based confocal laser endomicroscopy have allowed us to visualize the pancreas in even higher resolution and diagnose premalignant and malignant lesions of the pancreas with improved accuracy. This report reviews the range of imaging tools currently available to evaluate pancreatic lesions, from solid tumors to pancreatic cysts.

Role of endoscopic ultrasound in the diagnosis of pancreatic cancer

Endoscopic ultrasonography (EUS) with or without fine needle aspiration has become the main technique for evaluating pancreatobiliary disorders and has proved to have a higher diagnostic yield than positron emission tomography, computed tomography (CT) and transabdominal ultrasound for recognising early pancreatic tumors. As a diagnostic modality for pancreatic cancer, EUS has proved rates higher than 90%, especially for lesions less than 2-3 cm in size in which it reaches a sensitivity rate of 99% vs 55% for CT. Besides, EUS has a very high negative predictive value and thus EUS can reliably exclude pancreatic cancer. The complication rate of EUS is as low as 1.1%-3.0%. New technical developments such as elastography and the use of contrast agents have recently been applied to EUS, improving its diagnostic capability. EUS has been found to be superior to the recent multidetector CT for T staging with less risk of overstaying in comparison to both CT and magnetic resonance imaging, so that patients are not being ruled out of a potentially beneficial resection. The accuracy for N staging with EUS is 64%-82%. In unresectable cancers, EUS also plays a therapeutic role by means of treating oncological pain through celiac plexus block, biliary drainage in obstructive jaundice in patients where endoscopic retrograde cholangiopancreatography is not affordable and aiding radiotherapy and chemotherapy.

Applications of endoscopic ultrasound in pancreatic cancer

Since the introduction of endoscopic ultrasound guided fine-needle aspiration (EUS-FNA), EUS has assumed a growing role in the diagnosis and management of pancreatic ductal adenocarcinoma (PDAC). The objective of this review is to discuss the various applications of EUS and EUS-FNA in PDAC. Initially, its use for detection, diagnosis and staging will be described. EUS and EUS-FNA are highly accurate modalities for detection and diagnosis of PDAC, this high accuracy, however, is decreased in specific situations particularly in the presence of chronic pancreatitis. Novel techniques such as contrast-enhanced EUS, elastography and analysis of DNA markers such as k-ras mutation analysis in FNA samples are in progress and might improve the accuracy of EUS in the detection of PDAC in this setting and will be addressed. EUS and EUS-FNA have recently evolved from a diagnostic to a therapeutic technique in the management of PDAC. Significant developments in therapeutic EUS have occurred including advances in celiac plexus interventions with direct injection of ganglia and improved pain control, EUS-guided fiducial and brachytherapy seed placement, fine-needle injection of intra-tumoral agents and advances in EUS-guided biliary drainage. The future role of EUS and EUS in management of PDAC is still emerging.

Diagnostic accuracy of EUS and CT of vascular invasion in pancreatic cancer: a systematic review

OBJECTIVE

The objective of this study was to summarize the accuracy of preoperative vascular invasion with endoscopic ultrasound (EUS) and computed tomography (CT) test performance in pancreatic cancer with meta-analysis

METHOD

Two reviewers searched MEDLINE database to identify relevant studies. The reference lists of the trials were manually searched. Included studies used surgical and/or histological findings as the "gold standard," and provided sufficient data to construct a diagnostic 2 × 2 table. A statistical program of Meta-Disc was used to calculate the pooled sensitivity, specificity, positive LR, negative LR, DOR, and the SROC curve. Publication bias was assessed by Deeks' asymmetry test. Sensitivity analysis and subgroup analysis were calculated to down the heterogeneity. Meta-regression was calculated to evaluate potential sources of heterogeneity

RESULT

A total of 30 studies with 1,554 patients were included for the analysis, nine of these studies compared EUS with CT to assess the diagnostic efficiency The pooled sensitivity of EUS and CT was 72 % (95 % CI 67-77 %) and 63 % (95 % CI 58-67 %), and the pooled specificity of EUS and CT was 89 % (95 % CI 86-92 %) and 92 % (95 % CI 90-94 %), respectively. The positive LR of EUS and CT was 5.14 (95 % CI 3.14-8.40) and 6.21 (95 % CI 3.96-9.71), and the negative LR was 0.36 (95 % CI 0.25-0.52) and 0.41 (95 % CI 0.31-0.55), respectively. The AUCs of EUS and CT were 0.9037 and 0.8948. The subgroup analysis of nine studies performed both EUS and CT showed CT scan with a lower sensitivity of 48 % (95 % CI 0.40-0.56), when compared to EUS of 69 % (95 % CI 0.61-0.77). The overall AUCs of CT scan appear to be lower (AUCs = 0.8589), compared with EUS (AUCs = 0.9379) CONCLUSION: EUS performed better than CT in differentiating vascular invasion preoperative on pancreatic cancer. EUS could provide other additional information when compared with CT.

Systematic underreporting of the population-based incidence of pancreatic and biliary tract cancers

BACKGROUND

Incidence rates of cancers of the pancreas and biliary tract, typically derived from cancer registers, have been reported to be decreasing. This study tested whether pancreatic and biliary tract cancers are underreported in the Swedish Cancer Register (CR).

METHODS

The concordance of pancreatic and biliary tract cancer diagnoses in 1990-2009 between CR and the Swedish Patient Register (PR) were evaluated through record linkage. To further assess the completeness of these cancer diagnoses in both CR and PR, record linkage was also made to the Swedish Causes of Death Register (DR).

RESULTS

A total of 31 067 cases of pancreatic cancer and 14 273 cases of biliary tract cancer were identified in CR or PR. Altogether, 44% of the pancreatic cancers and 44% of the biliary tract cancers were registered in PR only, and not in CR. The concordance between CR and PR declined from 63% in the years 1990-1994 to 44% in 2005-2009 for pancreatic cancer. The corresponding figures for biliary tract cancer were 60% and 37%. This decline in concordance was also observed with increasing age, e.g. the concordance between CR and PR for pancreatic cancer declined from 62% in patients<60 years to 36% among patients≥80 years. The corresponding figures for biliary tract cancer were 52% and 38%.

CONCLUSION

There is an overwhelming underreporting of pancreatic and biliary tract cancers within the Swedish Cancer Register, which has increased during recent years. The reported decreasing incidence rates for pancreatic and biliary tract cancers might therefore be incorrect.

The role of routine preoperative EUS when performed after contrast enhanced CT in the diagnostic work-up in patients suspected of pancreatic or periampullary cancer

BACKGROUND

In patients suspected of pancreatic or periampullary cancer, abdominal contrast-enhanced computed tomography (CT) is the standard diagnostic modality. A supplementary endoscopic ultrasonography (EUS) is often performed, although there is only limited evidence of its additional diagnostic value. The aim of the study is to evaluate the additional diagnostic value of EUS over CT in deciding on exploratory laparotomy in patients suspected of pancreatic or periampullary cancer.

METHODS

We retrospectively analyzed 86 consecutive patients who routinely underwent CT and EUS before exploratory laparotomy with or without pancreatoduodenectomy for suspected pancreatic or periampullary carcinoma between 2007 and 2010. Primary outcomes were visibility of a mass, resectability on CT/EUS and resection with curative intent.

RESULTS

A mass was visible on CT in 72/86 (84%) patients. In these 72 patients, EUS demonstrated a mass in 64/72 (89%) patients. Resectability was accurately predicted by CT in 65/72 (90%) and by EUS in 58/72 (81%) patients. In 14/86 (16%) patients no mass was seen on CT. EUS showed a mass in 12/14 (86%) of these patients. A malignant lesion was histological proven in 11/12 (92%) of these patients. Overall, resectability was accurately predicted by CT and EUS in 90% (77/86) and 84% (72/86), respectively.

CONCLUSIONS

In patients with a visible mass on CT, suspected for pancreatic or periampullary cancer, EUS has no additional diagnostic value, does not influence the decision to perform laparotomy and should therefore not be performed routinely. In patients without a visible mass on CT, EUS is useful to confirm the presence of a tumor.

Technical Advances in Endoscopic Ultrasound (EUS)-Guided Tissue Acquisition for Pancreatic Cancers: How Can We Get the Best Results with EUS-Guided Fine Needle Aspiration?

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is one of the least invasive and most effective modality in diagnosing pancreatic adenocarcinoma in solid pancreatic lesions, with a higher diagnostic accuracy than cystic tumors. EUS-FNA has been shown to detect tumors less than 3 mm, due to high spatial resolution allowing the detection of very small lesions and vascular invasion, particularly in the pancreatic head and neck, which may not be detected on transverse computed tomography. Furthermore, this minimally invasive procedure is often ideal in the endoscopic procurement of tissue in patients with unresectable tumors. While EUS-FNA has been increasingly used as a diagnostic tool, most studies have collectively looked at all primary pancreatic solid lesions, including lymphomas and pancreatic neuroendocrine neoplasms, whereas very few studies have examined the diagnostic utility of EUS-FNA of pancreatic ductal carcinoma only. As with any novel and advanced endoscopic procedure that may incorporate several practices and approaches, endoscopists have adopted diverse techniques to improve the tissue procurement practice and increase diagnostic accuracy. In this article, we present a review of literature to date and discuss currently practiced EUS-FNA technique, including indications, technical details, equipment, patient selection, and diagnostic accuracy.

Performance characteristics of endoscopic ultrasound in the staging of pancreatic cancer: a meta-analysis

CONTEXT

The optimal approach to pre-operative imaging assessment of pancreatic cancer is unknown.

OBJECTIVE

The aim of this meta-analysis was to assess accuracy and performance characteristics of EUS in determining nodal staging, vascular invasion, and prediction of resectability of pancreatic cancer. A secondary aim was to perform head to head comparison of performance characteristics between EUS and CT for nodal staging, vascular invasion and resectability.

DESIGN

Data from EUS studies were pooled according to bivariate generalized random effects model. Pooled estimates for CT were obtained from studies which performed head to head comparison between EUS and CT.

PATIENTS

Patients with pancreatic cancer undergoing pre-operative imaging assessment.

INTERVENTION

EUS.

MAIN OUTCOME MEASURE

Pooled sensitivity, specificity, positive and negative predictive values of EUS for nodal staging, vascular invasion and resectability.

RESULTS

Forty-nine studies were considered of which 29 met inclusion criteria with a total of 1,330 patients. Pooled summary estimates for EUS-nodal staging were 69% for sensitivity and 81% for specificity. For vascular invasion, sensitivity was 85% and specificity was 91%. The sensitivity and specificity for resectability was 90% and 86%, respectively. CT scan showed lower sensitivity than EUS for nodal staging (24% vs. 58%) and vascular invasion (58% vs. 86%); however, the specificities for nodal staging (88% vs. 85%) and vascular invasion (95% vs. 93%) were comparable in studies where both imaging techniques were performed. The sensitivity and specificity of CT in determining resectability (90% and 69%) was similar to that of EUS (87% and 89%).

CONCLUSIONS

EUS is an accurate pre-operative tool in the assessment of nodal staging, vascular invasion and resectability in patients with pancreatic cancer.

Diagnostic Accuracy of Imaging Modalities in the Evaluation of Vascular Invasion in Pancreatic Adenocarcinoma: A Meta-Analysis

BACKGROUND

The extent of vascular invasion is a key factor determining the resectability of non-metastatic pancreatic adenocarcinoma. The purpose of this study is to determine the diagnostic accuracy of computed tomography (CT), endoscopic ultrasound (EUS), and magnetic resonance imaging (MRI) in the pre-operative evaluation of vascular invasion in pancreatic adenocarcinoma, with surgery as the reference standard.

METHODS

A search of the MEDLINE database for relevant articles in the English language published between January 2000 and February 2009 was performed. From each study, 2 × 2 tables were obtained, and pooled sensitivity, specificity, positive likelihood ratios, negative likelihood ratios and diagnostic odds ratios were calculated for each modality, along with a summary receiver operating characteristics (SROC) curve.

RESULTS

16 studies with a total of 797 patients who had surgical assessment of vascular invasion were included in the analysis. Several studies evaluated more than one imaging modality, allowing 24 datasets to be obtained in total. Sensitivity was highest for CT (0.73, 95% CI 0.67 - 0.79), followed by EUS (0.66, 95% CI 0.56 - 0.75) and MRI (0.63, 95% CI 0.48 - 0.77). The specificity for all three imaging modalities was comparable. The diagnostic odds ratios for CT, EUS and MRI were 45.9 (95% CI 18.0 - 117.4), 23.0 (95%CI 9.4 - 56.6), 23.9 (95% CI 5.4 - 105.1) respectively.

CONCLUSION

CT was more accurate than EUS and MRI in the evaluation of vascular invasion in pancreatic adenocarcinoma and should be the first line investigation in pre-operative staging.

Preoperative vascular evaluation with computed tomography and magnetic resonance imaging for pancreatic cancer: a meta-analysis

OBJECTIVES

Vascular invasion (VI) is the most important factor in assessing operability for pancreatic cancer. The accuracy of preoperative vascular staging with computed tomography (CT) and magnetic resonance imaging (MRI) was examined using meta-analysis.

METHODS

Published articles in pancreatic cancer comparing diagnostic accuracy of CT with MRI for VI confirmed on histology were searched from MEDLINE, EMBASE and ISI Web of Science databases. Pooled sensitivity, specificity, likelihood ratio, summary receiver operating characteristic (SROC) curve and area under curve (AUC) were analysed by SPSS 13.0 and Revmen 5.1.

RESULTS

Eight studies (n = 296) met the inclusion criteria. The pooled sensitivity of CT and MRI in diagnosing VI was 71% (95% CI, 64-78) and 67% (95% CI, 59-74), pooled specificity 92% (95% CI, 89-95) and 94% (95% CI, 91-96), positive likelihood ratio 6.33 (95% CI, 4.51-8.87) and 6.58 (95% CI, 4.62-9.37), negative likelihood ratio 0.34 (95% CI, 0.27-0.43) and 0.38 (95% CI, 0.30-0.47), and AUCs 0.87 and 0.76 (p = 0.63), respectively. There was no significant difference between CT and MRI for preoperative diagnosis of VI. Subgroup analysis of 4 studies (n = 143) showed no significant difference between CT and MRI in preoperative diagnosis of venous or arterial invasion (p = 0.73 and p = 0.81, respectively). When CT was compared with MRA in 3 studies (n = 110), again there was no significant difference for preoperative staging of VI (p = 0.54).

CONCLUSIONS

Both CT and MRI are underreporting vascular invasion preoperatively in pancreatic cancer. MRA does not add any additional information on vascular staging when compared with CT and MRI.

Pancreatic cancer: an endoscopic perspective

Pancreatic cancer continues to be a diagnostic and therapeutic challenge. The advent of endoscopic ultrasound-guided interventions have brought about a paradigm shift in the endoscopic approach to diagnosis, treatment and palliation of this common malignancy. The last decade has witnessed significant advances in techniques of endoscopic biliary drainage, endoluminal stenting, celiac plexus neurolysis and image-guided radiation therapy, which have transformed the scope of palliation in pancreatic cancer. Moreover, endoscopic ultrasound-aided intratumoral delivery of fiducials, radioisotopes and chemotherapeutic agents have shown promising results and warrant further investigation. This review summarizes the recent advances in endoscopic applications for the management of pancreatic neoplasms.

Current status of diagnostic endoscopic ultrasonography in the evaluation of pancreatic mass lesions

Endoscopic ultrasonography (EUS) is currently well established as a diagnostic method for the evaluation of pancreatic mass lesions. Diagnostic EUS might be divided into two broad categories; it is an imaging method, and also a device for obtaining cytopathology and histopathology. EUS as an imaging method has seen the introduction of newer intravenous contrast agents that enable the characterization of the pancreatic masses. EUS elastography enables real-time graphical representation of differential tissue hardness within a lesion. Contrast-enhanced EUS and/or elastography provide information additional to the fundamental images, leading to more accurate diagnosis. EUS-guided fine needle aspiration (EUS-FNA) has been shown to be a highly accurate method for distinguishing benign from malignant pancreatic masses. Several investigators have reported the usefulness of EUS-FNA samples obtained from pancreatic masses for genetic analysis, e.g. p53, K-ras. Genetic analysis of EUS-FNA samples to characterize chemo-sensitivity has recently been attempted in patients with unresectable pancreatic cancers. Although further improvement of EUS technology is desired to render it an even more convenient and reliable procedure, EUS at its current level of advancement is of proven utility in the diagnosis of pancreatic masses.

Endoscopic ultrasound staging and novel therapeutics for pancreatic cancer

Pancreatic cancer remains a challenging disease, being the fourth leading cause of death in both men and women in the United States. Patients with pancreatic cancer present with symptoms including jaundice, pruritus, and weight loss, which often herald advanced disease with little chance for curative resection. Multiple imaging modalities are used to diagnose and stage pancreatic cancer. This article discusses the utility of endoscopic ultrasound (EUS) for diagnosis and staging, and introduces novel EUS-guided therapeutic options for the treatment of pancreatic cancers. EUS-guided fine-needle injection of chemotherapy agents is a promising development in pancreatic tumor treatment.

Diagnosis of pancreatic tumors by endoscopic ultrasonography

Pancreatic tumors are highly diverse, as they can be solid or cystic, and benign or malignant. Since their imaging features overlap considerably, it is often difficult to characterize these tumors. In addition, small pancreatic tumors, especially those less than 2 cm in diameter, are difficult to detect and diagnose. For characterizing pancreatic tumors and detecting small pancreatic tumors, endoscopic ultrasonography (EUS) is the most sensitive of the imaging procedures currently available. This technique also provides good results in terms of the preoperative staging of pancreatic tumors. EUS-guided fine needle aspiration (EUS-FNA) has also proved to be a safe and useful method for tissue sampling of pancreatic tumors. Despite these advantages, however, it is still difficult to differentiate between benign and malignant, solid or cystic pancreatic tumors, malignant neoplasms, and chronic pancreatitis using EUS, even when EUS-FNA is performed. Recently, contrast-enhanced EUS with Doppler mode (CE-EUS) employing ultrasound contrast agents, which indicate vascularization in pancreatic lesions, has been found to be useful in the differential diagnosis of pancreatic tumors, especially small pancreatic tumors. However, Doppler ultrasonography with contrast-enhancement has several limitations, including blooming artifacts, poor spatial resolution, and low sensitivity to slow flow. Consequently, an echoendoscope was developed recently that has a broad-band transducer and an imaging mode that was designed specifically for contrast-enhanced harmonic EUS (CEH-EUS) with a second-generation ultrasound contrast agent. The CEH-EUS technique is expected to improve the differential diagnosis of pancreatic disease in the future. This review describes the EUS appearances of common solid and cystic pancreatic masses, the diagnostic accuracy of EUS-FNA, and the relative efficacies and advantages of CE-EUS and CEH-EUS along with their relative advantages and their complementary roles in clinical practice.

Detection of lymph node metastases by gadolinium-enhanced magnetic resonance imaging: systematic review and meta-analysis

BACKGROUND

Gadolinium-based contrast agents are used with magnetic resonance imaging (MRI) to highlight tumor vascularity in organs. They are also widely used for primary tumor visualization. We conducted a systematic review and meta-analysis of the existing evidence of the accuracy of gadolinium-enhanced MRI for staging lymph node metastases.

METHODS

We systematically searched the MEDLINE, Cochrane, CANCERLIT, and EMBASE databases for studies published in English or German from January 1, 1988, to January 1, 2008, that assessed the diagnostic accuracy of gadolinium-enhanced MRI in the evaluation of lymphatic metastases compared with histopathologic examination as the reference test. Based on a priori-defined clinical considerations, we studied three subgroups of studies: those that used a single malignancy criterion and those that used multiple malignancy criteria with or without contrast highlighting. Summaries of MRI sensitivity and specificity for detecting lymph node metastases were calculated using a bivariate regression model. All statistical tests were two-sided.

RESULTS

The literature search yielded 43 full-text papers that were considered for inclusion in the meta-analysis. We performed quantitative pooled analyses on the 32 studies that provided data on patient-level diagnosis. The weighted estimates of sensitivity and specificity for all studies combined were 0.72 (95% confidence interval [CI] = 0.66 to 0.79) and 0.87 (95% CI = 0.82 to 0.91). Estimates of sensitivity and specificity were essentially unchanged for studies that used a single malignancy criterion (0.71 [95% CI = 0.61 to 0.79] and 0.88 [95% CI = 0.80 to 0.93], respectively; n = 11 studies) or multiple malignancy criteria without contrast enhancement (0.70 [95% CI = 0.58 to 0.79] and 0.86 [95% CI = 0.68 to 0.94], respectively; n = 6 studies). The sensitivity increased to 0.84 (95% CI = 0.70 to 0.92), with a specificity of 0.82 (95% CI = 0.72 to 0.89) for the nine studies that incorporated contrast enhancement in their multiple malignancy criteria. Six studies did not define the malignancy criteria they used.

CONCLUSIONS

The overall accuracy of gadolinium-enhanced magnetic resonance imaging for the detection of nodal metastases is moderate. Incorporating contrast enhancement in the malignancy criteria substantially improves the accuracy of this diagnostic test.

Quantitative perfusion analysis of transabdominal contrast-enhanced ultrasonography of pancreatic masses and carcinomas

BACKGROUND & AIMS

Preoperative differential diagnosis of pancreatic ductal adenocarcinoma (PDAC) and focal masses in patients with chronic pancreatitis (CP) can be challenging. There are fine differences in the vascularization of these lesions; ultrasound contrast agents can aid in their differentiation. We evaluated the value of software-aided quantitative analysis of transabdominal contrast-enhanced ultrasonography for differential diagnosis of PDAC vs focal masses.

METHODS

Sixty patients for whom it was not possible to differentiate between an inflammatory focal lesion of the pancreas and a pancreatic carcinoma underwent contrast-enhanced ultrasonography with a second-generation contrast agent. Time-intensity curves were obtained for all exams in 2 regions of interest within the lesion and within the normal pancreatic tissue. Images were processed using Axius ACQ software; the following parameters were obtained: maximum intensity, arrival time, time-to-peak, and area under the curve. Absolute values and differences between the lesion and the normal tissue were evaluated.

RESULTS

Histology analysis revealed 45 PDACs and 15 inflammatory masses in patients with CP. Time-dependent parameters (arrival time and time to peak) were significantly longer in PDACs compared to focal masses. Although markedly lower than in healthy pancreata, the maximum intensity and area under the curve parameters were not significantly different between PDACs and focal lesions in patients with CP.

CONCLUSIONS

In cases of CP, PDAC and focal masses exhibit different perfusion patterns at a capillary level that can be visualized using the small microbubbles of ultrasound contrast agents. Contrast quantification software supplements a subjective visual assessment with objective criteria to facilitate the differential diagnosis of focal lesions in pancreatic cancer and chronic pancreatitis.

Secretin-stimulated multi-detector CT versus mangafodipir trisodium-enhanced MR imaging plus MRCP in characterization of non-metastatic solid pancreatic lesions

BACKGROUND AND AIM

Our study was aimed to compare multiphasic multi-detector computed tomography after secretin stimulation and mangafodipir trisodium-enhanced magnetic resonance imaging plus MR cholangiopancreatography in the characterization of solid pancreatic lesions.

PATIENTS AND METHODS

Forty patients with ultrasound diagnosis of solid pancreatic lesion prospectively underwent both multi-detector computed tomography and magnetic resonance imaging. Three minutes after intravenous administration of secretin, post-contrast computed tomography scans were performed 40, 80, and 180 s after contrast medium injection. MR protocol included axial/coronal, thin/thick-slab, single-shot T2 w sequences and axial/coronal T1 w breath-hold spoiled gradient-echo images before and 30-40 min after intravenous infusion of manganese dipyri-doxal diphosphate. Different observers blindly evaluated the ability of computed tomography and magnetic resonance imaging to characterize focal pancreatic lesions. Surgery, biopsy, and/or follow-up were considered as our diagnostic gold standard.

RESULTS

Thirty-five focal pancreatic lesions (adenocarcinoma, n=18; focal chronic pancreatitis, n=4; endocrine tumor, n=6; metastasis, n=1; cystic tumor, n=3; indeterminate cystic lesions, n=3) were present in 34 patients since the remaining 6 subjects showed no pathological finding. Both multi-detector computed tomography and magnetic resonance imaging showed a statistically significant correlation with the gold standard and between themselves in the characterization of 29 solid lesions of the pancreas (p<0.05).

CONCLUSION

Both imaging techniques well correlate to final diagnosis of non-metastatic solid pancreatic lesions and particularly of adenocarcinomas with a slight advantage for mangafodipir trisodium-enhanced magnetic resonance imaging plus MR cholangiopancreatography.

Endosonography in the management of biliopancreatic disorders

Over the past two decades, endoscopic endosonography (EUS) has evolved into an indispensible diagnostic and therapeutic utility in the diagnosis and treatment of patients with pancreatobiliary disease. In this article, we summarise its current potential and provide an update of the latest literature.

New concepts in staging and treatment of locally advanced pancreatic head cancer

OBJECTIVE

The objective of this article is to discuss the CT findings that guide surgeons in deciding the feasibility of tumor excision in patients with locally advanced pancreatic head cancers.

CONCLUSION

Vascular resection as an adjunct to pancreaticoduodenectomy is increasingly used in pancreatic head cancer. As a result, the imaging criteria to determine which patients are candidates for potentially curative resection are evolving.

Pancreatoscopy: present and future role

Current imaging modalities do not allow for direct access to the pancreatic duct. Because of this limitation, diagnosis and assessment of pancreatic diseases require radiographic imaging and cytologic analysis. Although many of these techniques have excellent specificity for the detection of pancreatic cancer, they offer no therapeutic capabilities and are relatively poor in early detection of cancer and in differentiating chronic pancreatitis from malignancy, particularly when the conditions coexist. Currently available cholangioscopes are too large to access the pancreatic duct without sphincterotomy or balloon dilation, increasing the risk of instrumentation trauma to the pancreas. Novel, dedicated pancreatoscopes have recently been developed and are under investigation in clinical trials. Preliminary evidence suggests that these new technologies allow for direct visualization of the pancreatic ducts, with the potential for forceps biopsy in suspected malignancy and endotherapy for pancreatic calculi. Future and ongoing clinical trials will better define the utility and roles of these new endoscopy tools.

Diagnostic accuracy of EUS for vascular invasion in pancreatic and periampullary cancers: a meta-analysis and systematic review

BACKGROUND

Vascular invasion (VI) in a patient with pancreatic or periampullary cancers precludes surgery and indicates a poor prognosis. Published data on the accuracy of EUS in diagnosing VI is varied.

OBJECTIVE

The aim of this meta-analysis was to evaluate the accuracy of EUS in diagnosing VI in patients with pancreatic and periampullary cancers.

DESIGN

Data from EUS studies were pooled according to the Mantel-Haenszel and DerSimonian Laird methods.

PATIENTS

EUS studies in which VI was confirmed by surgery or angiography were selected.

INTERVENTIONS

EUS.

MAIN OUTCOME MEASURES

Pooled estimates of sensitivity, specificity, likelihood ratios, and diagnostic odds ratio of EUS.

RESULTS

Data were extracted from 29 studies (N = 1308) that met the inclusion criteria. The pooled sensitivity of EUS in diagnosing VI was 73% (95% CI, 68.8-76.9) and the pooled specificity was 90.2% (95% CI, 87.9-92.2). The positive likelihood ratio for diagnosing VI by EUS was 9.1 (95% CI, 4.6-17.9) and the negative likelihood ratio was 0.3 (95% CI, 0.2-0.5). Diagnostic odds ratio, the odds of having VI in positive as compared with negative EUS studies, was 40.1 (95% CI, 16.1-99.9). The P value for chi(2) heterogeneity for all the pooled estimates was >.05.

CONCLUSIONS

Although EUS is the best noninvasive test to diagnose VI in pancreatic and periampullary cancers, this meta-analysis showed that the specificity (90%) is high but the sensitivity (73%) is not as high as suggested. Further refinements in EUS technologies and interpretation may improve the sensitivity for detecting VI.

Pancreatic imaging: current and emerging technologies

This review discusses the current imaging modalities for the diagnosis and staging of solid and cystic pancreatic lesions and for the assessment of acute and chronic pancreatitis, and the future role of emerging technologies in the management of pancreatic diseases. Multidetector row spiral computed tomography is superior to conventional single-detector row spiral computed tomography in the detection and staging of pancreatic adenocarcinoma. Positron emission tomography is a sensitive but relatively nonspecific diagnostic modality. Positron emission tomography-computed tomography fusion may improve the staging accuracy for pancreatic cancer. Echo-enhanced ultrasound may have an emerging role in evaluating pancreatic masses. Endoscopic ultrasound with fine needle aspiration for cytology is the single best method for diagnosis and staging of nonmetastatic pancreatic cancer with a high accuracy for determining tumor resectability. In acute pancreatitis, a modification of the standard computed tomography severity index, which places greater emphasis on extrapancreatic complications, has shown superior correlation with various patient outcome measures. Endoscopic retrograde cholangiopancreatography is still the test of choice for morphological evaluation of chronic pancreatitis, whereas magnetic resonance cholangiopancreatography offers a noninvasive alternative in selected patients. Endoscopic ultrasound can be useful for detecting early chronic pancreatitis. Secretin-stimulated imaging techniques may eventually provide a noninvasive method of reliably assessing pancreatic exocrine function.

Pancreatic adenocarcinoma: MDCT versus MRI in the detection and assessment of locoregional extension

PURPOSE

To compare dynamic-contrast enhanced multirow detector computed tomography (MDCT) including multiplanar reformatted images (MPR) and magnetic resonance imaging (MRI) including magnetic resonance cholangiopancreatography images for the detection and assessment of locoregional extension of pancreatic adenocarcinoma.

MATERIALS AND METHODS

Twenty-four patients with and 21 patients without pancreatic adenocarcinoma underwent triple-phase MDCT and MRI. Three radiologists independently attempted to detect pancreatic adenocarcinoma and assess locoregional extension in 3 sessions. First session involved MDCT images. In the second session, radiologists had access to coronal and sagittal MPR images together with the axial images (MDCT + MPR). Third session involved MR images. Results were compared with surgical findings using receiver operating characteristic analysis and kappa statistics.

RESULTS

Regarding tumor detection, MDCT + MPR had a significantly higher value for areas under the curve (0.96 +/- 0.02) at receiver operating characteristic analysis compared with those of MRI (0.90 +/- 0.03) and MDCT (0.85 +/- 0.04). MDCT + MPR had the highest mean sensitivity (96%), and MRI had the highest mean specificity (98%). For locoregional extension, MDCT + MPR showed the highest kappa values of the study for all factors evaluated (range, 0.63-0.86).

CONCLUSIONS

In conclusion, multiphasic MDCT imaging with MPR images was superior to multiphasic MDCT imaging without MPR images and to comprehensive MRI employing 2-D sequences and magnetic resonance cholangiopancreatography for both the detection and assessment of locoregional extension of pancreatic adenocarcinomas. MRI might be used for further lesion characterization regarding its high specificity.

Comparison of endoscopic ultrasound and computed tomography for the preoperative evaluation of pancreatic cancer: a systematic review

BACKGROUND & AIMS

It is uncertain whether computed tomography (CT) or endoscopic ultrasound (EUS) is superior for the detection, staging, and resectability of pancreatic cancer. We therefore performed a systematic literature review to determine which test is more accurate.

METHODS

We identified relevant studies from MEDLINE (1986-2004) and evaluated study quality, which was measured on the basis of guidelines for assessing studies of diagnostic tests. Quantitative outcomes data were abstracted from the studies.

RESULTS

Eleven studies with 678 patients satisfied inclusion criteria. Nine studies assessed tumor detection, all of which concluded that the sensitivity of EUS was superior to CT. Four of 5 studies that assessed tumor staging accuracy and 5 of 8 that assessed nodal staging accuracy concluded that EUS was superior to CT. Among the 4 studies that assessed resectability, 2 showed no difference between EUS and CT, and 1 favored each modality. Three of 11 studies met all but one of the quality criteria. The most important and frequent study limitations were lack of a consecutive series of patients and biased patient selection for surgery. Quantitative comparisons among studies were precluded by differences in tumor staging classifications, surgical selection, CT and EUS techniques, and reporting of operating characteristics.

CONCLUSIONS

The published literature comparing EUS and CT for preoperative assessment of pancreatic cancer is heterogeneous in study design, quality, and results. All studies have methodologic limitations that potentially affect validity. Prospective studies with state-of-the-art imaging are needed to further define the role of each test.

Mangafodipir trisodium-enhanced MR imaging of pancreatic disease

Our study aimed to assess the diagnostic capabilities of mangafodipir trisodium-enhanced MRI for the evaluation of pancreatic disease. Sixty-three patients suspected of having pancreatic disease underwent MRI with a 1.5-T device. After the acquisition of axial and coronal T2-weighted sequences, the MR protocol included T1-weighted fat-suppressed breath-hold SPGR images obtained before and 30 min after the infusion of Mn-DPDP (Teslascan). The detection of a focal pancreatic lesion and its intensity were evaluated in consensus by two observers, who also attempted to characterize each lesion as benign or malignant. The reviewers were blinded to patient identification and all clinical, laboratory and previous imaging findings. MR imaging results were correlated with surgery (n=37), laparoscopy (n=1), biopsy (n=2) and imaging follow-up (n=22). Sixty-two subjects were effectively included in our analysis because one patient was lost to follow-up; final malignant and benign diagnoses were determined in 22 (35%) and 29 (47%) of the patients, respectively. The level of confidence in the diagnosis of the pancreatic lesion was significantly increased by the administration of Mn-DPDP as demonstrated by ROC analysis of unenhanced and post-contrast image sets (P=0.009). Overall, on the basis of observers' readings, MR assessment of pancreatic disease resulted in 57 correct diagnoses (accuracy, 92%) and five (8%) incorrect diagnoses. The sensitivity, specificity, positive predictive value and negative predictive value of the reviewers for the detection of pancreatic lesions and for the differentiation between benign and malignant masses were 91% (95% CI: 84 and 98%), 93% (95% CI: 86 and 99%), 87% (95% CI: 79 and 95%) and 95% (95% CI: 89 and 100%), respectively. Mn-DPDP-enhanced MRI is an effective diagnostic tool for evaluating pancreatic disease.

New advances in pancreatic imaging

PURPOSE OF REVIEW

Exciting new developments and applications of imaging techniques in pancreatic diseases have emerged. This review discusses these new advances and how they are improving our ability to diagnose malignancies and inflammatory lesions, to grade severity of pancreatitis, and to stage pancreatic cancer accurately.

RECENT FINDINGS

A new computed tomography severity index shows promise for grading the severity of acute pancreatitis. Magnetic resonance imaging is comparable with computed tomography in staging acute pancreatitis. Analysis of pancreatograms and textural changes of the parenchyma may prove helpful in diagnosing chronic pancreatitis. Contrast enhanced ultrasonography may prove to be a useful way to judge the degree of inflammation and fibrosis in autoimmune pancreatitis and to monitor response to steroid therapy. The debate over the best means of staging pancreatic cancer has focused on endoscopic ultrasound and computed tomography. Preliminary studies with contrast enhanced ultrasonography report improved diagnostic and staging capabilities with pancreatic cystic and solid neoplasms. Improvements in positron emission tomography/computed tomography scans may improve the detection of neuroendocrine tumors.

SUMMARY

These new advances will help refine the diagnosis and staging of pancreatic diseases.

Preoperative assessment of pancreatic tumors using magnetic resonance imaging, endoscopic ultrasonography, positron emission tomography and laparoscopy

BACKGROUND

The appropriate preoperative evaluation of a pancreatic tumor remains a matter of debate.

METHODS

We retrospectively evaluated an institutional strategy including magnetic resonance imaging (MRI), endoscopic ultrasonography (EUS), positron emission tomography (PET) and laparoscopy (LAP) for detection and staging of pancreatic tumors suspected to be malignant.

RESULTS

In a consecutive series of 59 patients screened by MRI, PET, EUS and LAP between July 1998 and November 2002, 48 patients were found to bear pancreatic adenocarcinoma and surgery was performed in 27 of them. For tumor detection, the sensitivity of EUS was superior to MRI and PET (98 vs. 87.5 and 87.5%, respectively, p = 0.13). MRI best assessed loco-regional staging, i.e. arterial involvement. For the detection of distant metastases, the sensitivity of all preoperative examinations taken separately was low. When laparotomy was performed with a curative intent according to all four examinations, occult metastasis or carcinomatosis was discovered in 7/27 patients and the overall predictive value of resectability was thus 74%. Five-year and median survival were significantly better in resected vs. non-resected patients (39% and 26 months vs. 0% and 8 months, p = 0.0006).

CONCLUSIONS

MRI can be recommended has the first examination in patients bearing pancreatic tumors, complemented by EUS if the findings of MRI are non-conclusive. For detection of distant metastasis, only the combination of all preoperative examination was proved to be more accurate than a single technique.