Preoperative staging of biliary carcinoma using 18F-fluorodeoxyglucose PET: prospective comparison with PET+CT, MDCT and histopathology

Cholangiocarcinoma imaging: from diagnosis to response assessment

Cholangiocarcinoma (CCA), a highly aggressive primary liver cancer arising from the bile duct epithelium, represents a substantial proportion of hepatobiliary malignancies, posing formidable challenges in diagnosis and treatment. Notably, the global incidence of intrahepatic CCA has seen a rise, necessitating a critical examination of diagnostic and management strategies, especially due to presence of close imaging mimics such as hepatocellular carcinoma (HCC) and combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA). Hence, it is imperative to understand the role of various imaging modalities such as ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), elucidating their strengths, and limitations in diagnostic precision and staging accuracy. Beyond conventional approaches, there is emerging significance of functional imaging tools including positron emission tomography (PET)-CT and diffusion-weighted (DW)-MRI, providing pivotal insights into diagnosis, therapeutic assessment, and prognostic evaluation. This comprehensive review explores the risk factors, classification, clinical features, and role of imaging in the holistic spectrum of diagnosis, staging, management, and restaging for CCA, hence serving as a valuable resource for radiologists evaluating CCA.

Imaging of Hepatobiliary Cancer

The liver and biliary tree are common sites of primary and secondary malignancies. MRI followed by CT is the mainstay for the imaging characterization of these malignancies with the dynamically acquired contrast enhanced phases being the most important for diagnosis. The liver imaging reporting and data system classification provides a useful framework for reporting lesions in patents with underlying cirrhosis or who are at high risk for developing hepatocellular carcinoma. Detection of metastases is improved with the use of liver specific MRI contrast agents and diffusion weighted sequences. Aside from hepatocellular carcinoma, which is often diagnosed noninvasively, other primary hepatobiliary tumors may require biopsy for definite diagnosis, especially when presenting with nonclassic imaging findings. In this review, we examine the imaging findings of common and less common hepatobiliary tumors.

Endoscopic ultrasound in patients with resectable perihilar cholangiocarcinoma: impact on clinical decision-making

Background and study aims  Accurate assessment of the lymph node (LN) status is crucial in resectable perihilar cholangiocarcinoma (pCCA) to prevent major surgery in patients with extraregional metastatic LNs (MLNs). This study investigates the added value of preoperative endoscopic ultrasound (EUS) with or without tissue acquisition (TA) for the detection of MLNs in patients with resectable pCCA. Patients and methods  In this retrospective, multicenter cohort study, patients with potentially resectable pCCA who underwent EUS preoperatively between 2010-2020, were included. The clinical impact of EUS-TA was defined as the percentage of patients who did not undergo surgical resection due to MLNs found with EUS-TA. Findings of cross-sectional imaging were compared with EUS-TA findings and surgery. Results  EUS was performed on 141 patients, of whom 107 (76 %) had suspicious LNs on cross-sectional imaging. Surgical exploration was prevented in 20 patients (14 %) because EUS-TA detected MLNs, of which 17 (85 %) were extraregional. Finally, 74 patients (52 %) underwent surgical exploration followed by complete resection in 40 (28 %). MLNs were identified at definitive pathology in 24 (33 %) patients, of which 9 (38 %) were extraregional and 15 (63 %) regional. Conclusions  EUS-TA may be of value in patients with potentially resectable pCCA based on preoperative cross-sectional imaging, regardless of lymphadenopathy at cross-sectional imaging. A prospective study in which a comprehensive EUS investigation with LN assessment and EUS-TA of LNs is performed routinely should confirm this promise.

Evaluation of the 8th Edition AJCC Staging System for the Clinical Staging of Pancreatic Cancer

The 8th edition of the American Joint Committee on Cancer (AJCC) staging system for pancreatic cancer (PC) has been validated for pathological staging; however, its significance for clinical staging remains uncertain. We validated the prognostic performance and suitability of the current staging system for the clinical staging of PC. We identified 1043 patients from our PC registry who were staged by imaging according to the 8th edition staging system and conducted analysis, including overall survival (OS) comparison. Gradual prognostic stratification according to stage hierarchy yielded significant OS differences between stage groups, except between stage I and II (p = 0.193). A substage comparison revealed no survival differences between IB (T2N0) and IIA (T3N0), which were divided by the T3 criterion only (p = 0.278). A higher N stage had significantly shorter OS than a lower N stage (all pairwise p < 0.05). However, among the 150 patients who received upfront surgery, the pathological stage was more advanced than the clinical stage in 86 (57.3%), mostly due to a false-negative cN0 (70.9%). Our results suggest that the new definition of T3 and the number-based N criteria in the 8th edition AJCC staging system may be not adequate for clinical staging. Establishing separate criteria more suitable for clinical staging should be considered.

The usefulness of endoscopic ultrasound in the diagnosis of gallbladder lesions

Gallbladder tumors are neoplastic lesions; however, it can be difficult to distinguish between benign and malignant gall bladder tumors before surgery, although endoscopic ultrasound (EUS) is useful for differentiation. Fundamental B mode EUS (FB-EUS) and contrast-enhanced harmonic EUS (CH-EUS) are reported to be useful for the diagnosis of gallbladder tumor because they allow evaluation of polypoid lesion and gallbladder wall thickening. Scoring systems based on FB-EUS imaging are available for the diagnosis of malignant gallbladder polypoid lesions. The characteristic findings of malignant gallbladder polypoid lesions on CH-EUS include the presence of irregular intratumoral vessels and perfusion defects. The characteristic findings of malignant gallbladder wall thickening on FB-EUS include wall thickening >12 mm, hypoechoic internal echogenicity, inhomogeneous internal echo pattern, and disrupted wall layer, whereas CH-EUS findings include hypovascular enhancement and inhomogeneous contrast distribution pattern. In addition, FB-EUS and CH-EUS are useful for evaluating the stage of gallbladder carcinoma because they allow the evaluation of the depth of invasion of the gallbladder wall. It is usually difficult to obtain pathological evidence from gallbladder tumors before surgery and chemotherapy, even though the histological diagnosis is necessary for determining treatment policy. EUS-guided fine needle aspiration (EUS-FNA) is useful for obtaining pathological samples from gallbladder tumors before surgery and chemotherapy. The accuracy rate of EUS-FNA for gallbladder tumor is as high as 90%, but complications such as bile leakage and needle track seeding can be a problem, although it was reported that contrast-enhanced harmonic imaging is useful for avoiding them.

Preoperative FDG-Positive Lymph Nodes Predict the Postoperative Prognosis in Resectable Biliary Tract Cancers

BACKGROUND

F-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) has been used to diagnose and stage various cancers. In regard to biliary tract cancer (BTC), due to cholangitis it is difficult to evaluate FDG uptake caused by cancer. We previously showed that FDG-positive lymph nodes (LNs) of resectable BTC had a possibility of predicting postoperative prognosis.

OBJECTIVE

This study aimed to validate the usability of FDG-PET for LNs using another cohort and to investigate in detail the relationship between FDG-positive LNs and the prognosis of BTC.

METHODS

We measured the preoperative maximum standardized uptake value (SUV_max) at each of the 190 surgically dissected LN areas in 67 patients and investigated the prognosis using our previously determined SUV_max cut-off values of ≥ 2.8.

RESULTS

Regarding the prognosis of patients with resectable BTC, a LN SUV_max ≥ 2.8 [PET N (+)] was a poor prognostic factor for recurrence-free survival (RFS) compared with a LN SUV_max < 2.8 [PET N (-)]. It was confirmed that the hazard ratio forest plot [PET N (+)/PET N (-)] for RFS indicated a similar tendency among subcategories. Moreover, we investigated patients with pN0 disease and demonstrated that the PET N (+) group also had a significantly worse RFS outcome compared with the PET N (-) group. Recurrence of the PET N (+) group has significantly occurred more often in LNs than that of the PET N (-) group.

CONCLUSION

High LN SUV_max was confirmed to be the preoperatively diagnosed prognostic risk factor for RFS in resectable BTC and could be helpful for clinical decision making regarding the perioperative treatment strategy.

ACR Appropriateness Criteria® Jaundice

Jaundice is the end result of myriad causes, which makes the role of imaging in this setting particularly challenging. In the United States, the most common causes of all types of jaundice fall into four categories including hepatitis, alcoholic liver disease, blockage of the common bile duct by a gallstone or tumor, and toxic reaction to a drug or medicinal herb. Clinically, differentiating between the various potential etiologies of jaundice requires a detailed history, targeted physical examination, and pertinent laboratory studies, the results of which allow the physician to categorize the type of jaundice into mechanical or nonmechanical causes. Imaging modalities used to evaluate the jaundiced patient (all etiologies) include abdominal ultrasound (US), CT, MR cholangiopancreatography, endoscopic retrograde cholangiopancreatography and endoscopic US. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Diagnostic Performance and Prognostic Relevance of FDG Positron Emission Tomography/Computed Tomography for Patients with Extrahepatic Cholangiocarcinoma

Objective

We aimed to evaluate the diagnostic value and prognostic relevance of FDG positron emission tomography/computed tomography (PET-CT) in extrahepatic cholangiocarcinoma patients.

Materials and Methods

This study included 234 extrahepatic cholangiocarcinoma patients who underwent FDG PET-CT between June 2008 and February 2016. The diagnostic performance of FDG PEG-CT was compared to that of contrast-enhanced multidetector row CT (MDCT) and MRI. Independent prognosticators for poor survival were also assessed.

Results

The sensitivity of FDG PET-CT for detecting primary tumor and regional lymph node metastases was lower than that of MDCT or MRI (p < 0.001), whereas the specificity and positive predictive value for detecting regional lymph nodes metastases was significantly better in FDG PET-CT compared to MDCT and MRI (all p < 0.001). There was no significant difference in the diagnostic yield of distant metastases detection among three diagnostic imaging techniques. In a multivariate analysis, maximum standardized uptake values (SUV_max) of the primary tumor (adjusted hazard ratio [HR], 1.75; 95% confidence interval [CI], 1.13–2.69) and of the metastatic lesions ≥ 5 (adjusted HR, 8.10; 95% CI, 1.96–33.5) were independent contributors to poor overall survival in extrahepatic cholangiocarcinoma patients. In a subgroup analysis of 187 patients with periductal infiltrating type of cholangiocarcinoma, an SUV_max of the primary tumor ≥ 5 was associated with an increased risk of regional lymph node (adjusted odds ratio [OR], 1.60; 95% CI, 0.55–4.63) and distant metastases (adjusted OR, 100.57; 95% CI, 3.94–2567.43) at diagnosis as well as with poor overall survival (adjusted HR, 1.81; 95% CI, 1.04–3.15).

Conclusion

FDG PET-CT showed lower sensitivity for detecting primary tumor and regional lymph node involvement than MDCT and MRI. However, the SUV_max of primary tumors and metastatic lesions derived from FDG PET-CT could have significant implications for predicting prognoses in extrahepatic cholangiocarcinoma patients.

Pancreatic cancer surgical management

Pancreatic ductal adenocarcinoma (PDAC) remains a dismal prognosis and surgery is the only chance for cure. However, only few of the patients have localized tumor eligible for curative complete resection. Preoperative management and well-staging of the disease are the cornerstone for appropriate surgery and major issues to define the best therapeutic strategy. This review focuses on the surgical and optimal perioperative management of PDAC and summarizes updates data on the subject.

Pancreatic Adenocarcinoma Staging in the Era of Preoperative Chemotherapy and Radiation Therapy

Pancreatic ductal adenocarcinoma (PDA) remains among the most challenging malignancies to treat. At diagnosis, the tumor often already extends beyond the confines of the pancreas, spreading to an extent such that primary surgery with curative intent is very rarely feasible. Considerable momentum is now being given to a treatment strategy involving neoadjuvant chemotherapy or chemotherapy and radiation therapy in patients with nonmetastatic PDA. The main advantage of this strategy is better selection of patients likely to benefit from curative-intent surgery through the achievement of negative resection margins. Patients with rapidly progressive disease are identified and are spared ineffective surgery with its attendant morbidity. Neoadjuvant therapy can downstage tumors classified as locally advanced at initial imaging studies to resectable tumors. However, the imaging study evaluation of the response to neoadjuvant therapy is extremely complex. Thus, the diagnostic performance of imaging studies is not sufficient to ensure the accurate selection of patients in whom negative-margin resection is likely to be achieved. More specifically, standard criteria for predicting vascular invasion, based on the amount of tumor-vessel contact, are not valid after neoadjuvant therapy. ^©RSNA, 2018.

Value of 18F-FDG PET/CT Combined With Tumor Markers in the Evaluation of Ascites

OBJECTIVE

The purpose of this study is to investigate the value of ¹⁸F-FDG PET/CT combined with assessment of tumor markers in serum or ascites for the diagnosing and determining the prognosis of benign and malignant ascites.

MATERIALS AND METHODS

Patients with ascites of unknown cause who underwent evaluation with FDG PET/CT were included in this retrospective study. The maximum standardized uptake value (SUV_max) and levels of the tumor markers carbohydrate antigen-125 (CA-125) and carcinoembryonic antigen (CEA) in serum and ascites were recorded. The diagnostic values of FDG PET/CT, CEA and CA-125 levels in serum or ascites, and the combination of imaging plus tumor marker assessment were evaluated. Factors that were predictive of survival were also analyzed.

RESULTS

A total of 177 patients were included. Malignant ascites was eventually diagnosed in 104 patients, and benign ascites was diagnosed in the remaining 73 patients. With the use of FDG PET/CT, 44 patients (42.3%) were found to have primary tumors. The sensitivity, specificity, and accuracy of FDG PET/CT were 92.3%, 83.6%, and 88.7%, respectively. CA-125 levels in serum and ascites showed much better sensitivity than did CEA levels, but they showed significantly lower specificity. If the combination of tumor markers and FDG PET/CT was analyzed, the sensitivity, specificity, and accuracy of tumor markers in serum were 96.6%, 78.1%, and 88.7%, and those of tumor markers in ascites were 97.7%, 80.0%, and 90.4%, respectively. Sex may be an important factor affecting survival time (hazard ratio, 0.471; p = 0.004), but age, CEA level, and FDG PET/CT findings could not predict survival.

CONCLUSION

FDG PET/CT combined with assessment of tumor markers, especially CEA, increased the efficacy of diagnosis of ascites of unknown causes. Male sex conferred a poorer prognosis, whereas age, CEA level, and FDG uptake had no predictive significance in patients with malignant ascites.

Impact of EUS-FNA for preoperative para-aortic lymph node staging in patients with pancreatobiliary cancer

BACKGROUND AND AIMS

In patients with pancreatobiliary cancer, para-aortic lymph node (PALN) metastasis is considered to be the involvement beyond the regional lymph nodes, namely, distant metastasis. Effective methods for preoperative PALN staging, however, are not established. This study aimed to compare the diagnostic capability for PALN metastasis between EUS-FNA and (18)F-fluorodeoxyglucose positron emission tomography with CT (PET/CT).

METHODS

We performed a prospective, nonrandomized, single-center trial. Between December 2010 and March 2014, 208 patients with pancreatobiliary cancer without apparent distant metastasis except for PALNs were assessed for study eligibility before surgery. Among them, 52 consecutive patients with PALN enlargement were enrolled in the study. (18)F-Fluorodeoxyglucose PET/CT and EUS-FNA were performed sequentially as a single combined procedure to evaluate PALN metastases. The primary outcome was to compare the diagnostic capability of EUS-FNA and PET/CT for PALN metastasis.

RESULTS

Of 71 enlarged PALNs in the 52 patients, 30 (42.3%) were finally diagnosed as metastases in 21 patients (40.4%). Of the 21 patients with PALN metastases, preoperative EUS-FNA or PET/CT made a correct diagnosis in 20 (95.2%) or 12 (57.1%), respectively. EUS-FNA had higher sensitivity and specificity for the diagnosis of PALN metastasis (sensitivity, 96.7% [29/30]; 95% confidence interval, 82.2%-99.9%; specificity, 100% [39/39]; 95% confidence interval, 91.0%-100%) than PET/CT.

CONCLUSIONS

EUS-FNA is superior to PET/CT for preoperative PALN staging in patients with pancreatobiliary cancer. Because of the clinical benefit of EUS-FNA to reduce unnecessary surgery, it should be part of the standard preoperative examination for patients with pancreatobiliary cancer. (UMIN clinical trials registry number: 000006408.).

Diagnostic accuracy of fluorine-18-fluorodeoxyglucose positron emission tomography in gallbladder cancer: A meta-analysis

AIM: To meta-analyze published data about the diagnostic accuracy of fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) and PET/computed tomography (PET/CT) in the evaluation of primary tumor in patients with gallbladder cancer (GBCa).

METHODS: A comprehensive literature search of studies published through 30^th June 2014 regarding the role of ¹⁸F-FDG PET and PET/CT in the evaluation of primary gallbladder cancer (GBCa) was performed. All retrieved studies were reviewed. Pooled sensitivity and specificity of ¹⁸F-FDG PET or PET/CT in the evaluation of primary GBCa were calculated. The area under the summary receiving operator characteristics curve (AUC) was calculated to measure the accuracy of these methods. Sub-analyses considering the device used (PET vs PET/CT) were carried out.

RESULTS: Twenty-one studies comprising 495 patients who underwent ¹⁸F-FDG PET or PET/CT for suspicious GBCa were selected for the systematic review. The meta-analysis of 13 selected studies provided the following results: sensitivity 87% (95%CI: 82%-92%), specificity 78% (95%CI: 68%-86%). The AUC was 0.88. Improvement of sensitivity and specificity was observed when PET/CT was used.

CONCLUSION: ¹⁸F-FDG-PET and PET/CT demonstrated to be useful diagnostic imaging methods in the assessment of primary tumor in GBCa patients, nevertheless possible sources of false-negative and false-positive results should be kept in mind. PET/CT seems to have a better diagnostic accuracy than PET alone in this setting.

Diagnostic accuracy of CT in assessing extra-regional lymphadenopathy in pancreatic and peri-ampullary cancer: a systematic review and meta-analysis

OBJECTIVES

Computed tomography (CT) is the most widely used method to assess resectability of pancreatic and peri-ampullary cancer. One of the contra-indications for curative resection is the presence of extra-regional lymph node metastases. This meta-analysis investigates the accuracy of CT in assessing extra-regional lymph node metastases in pancreatic and peri-ampullary cancer.

METHODS

We systematically reviewed the literature according to the PRISMA guidelines. Studies reporting on CT assessment of extra-regional lymph nodes in patients undergoing pancreatoduodenectomy were included. Data on baseline characteristics, CT-investigations and histopathological outcomes were extracted. Diagnostic accuracy, positive predictive value (PPV), negative predictive value (NPV), sensitivity and specificity were calculated for individual studies and pooled data.

RESULTS

After screening, 4 cohort studies reporting on CT-findings and histopathological outcome in 157 patients with pancreatic or peri-ampullary cancer were included. Overall, diagnostic accuracy, specificity and NPV varied from 63 to 81, 80-100% and 67-90% respectively. However, PPV and sensitivity ranged from 0 to 100% and 0-38%. Pooled sensitivity, specificity, PPV and NPV were 25%, 86%, 28% and 84% respectively.

CONCLUSIONS

CT has a low diagnostic accuracy in assessing extra-regional lymph node metastases in pancreatic and peri-ampullary cancer. Therefore, suspicion of extra-regional lymph node metastases on CT alone should not be considered a contra-indication for exploration.

[18F]Fluorodeoxyglucose PET/Computed Tomography in Gastrointestinal Malignancies

This article discusses the current state-of-the-art application of 2-deoxy-2-[(18)F]fluoro-d-glucose (FDG)-PET and FDG-PET/computed tomography (CT) in the management of patients with gastrointestinal malignancies. Gastrointestinal malignancies include many different cell types, several common malignancies of which may be imaged by FDG-PET/CT. This review focuses on gastric carcinoma, pancreatic carcinoma, hepatocellular carcinoma, cholangiocarcinoma, colorectal carcinoma, and stroma cell tumors. The role of FDG-PET/CT in staging these malignancies is discussed, in addition to (re)staging, detection of recurrent disease, patient selection/prognostication, and response assessment, using the currently available literature.

Diagnostic accuracy of fluorine-18-fluorodeoxyglucose positron emission tomography in the evaluation of the primary tumor in patients with cholangiocarcinoma: a meta-analysis

OBJECTIVE

To meta-analyze published data about the diagnostic accuracy of fluorine-18-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) or PET/computed tomography (PET/CT) for primary tumor evaluation in patients with cholangiocarcinoma (CCa).

METHODS

A comprehensive literature search of studies published through December 31, 2013, was performed. Pooled sensitivity and specificity were calculated on a per patient based analysis. Subgroup analyses considering the device used (PET versus PET/CT) and the localization of the primary tumor (intrahepatic cholangiocarcinoma (IH-CCa), extrahepatic cholangiocarcinoma (EH-CCa), and hilar cholangiocarcinoma (H-CCa)) were carried out.

RESULTS

Twenty-three studies including 1232 patients were included in the meta-analysis. Pooled sensitivity and specificity of (18)F-FDG-PET or PET/CT were 81% and 82%, respectively. Pooled sensitivity and specificity, respectively, were 80% and 89% for PET, 82% and 75% for PET/CT, 95% and 83% for IH-CCa, 84% and 95% for H-CCa, and 76% and 74% for EH-CCa.

CONCLUSIONS

(18)F-FDG-PET and PET/CT were demonstrated to be accurate diagnostic imaging methods for primary tumor evaluation in patients with CCa. These tools have a better diagnostic accuracy in patients with IH-CCa than in patients with EH-CCa. Further studies are needed to evaluate the accuracy of (18)F-FDG-PET or PET/CT in patients with H-CCa.

Clinicopathological features of long-term survivors for advanced biliary tract cancer and impact of the number of lymph nodes involved

BACKGROUND & AIM

To investigate the characteristics of long-term survivors after surgery for advanced biliary tract cancer (BTC), especially those with local invasion and/or lymph node involvement.

METHODS

We analyzed the features of long-term survivors using a prospectively collected database and verified the results using recent patients' data which have been well-described, especially in relation to lymph node dissection and metastasis. We used classification by the Japanese Society of Biliary Surgery (JSBS).

RESULTS

Among 170 patients with advanced BTC (Stage III or IV in JSBS), 25 (10 bile duct cancer, 9 gall bladder cancer, and 6 cancer of the papilla of Vater) survived for more than 5 years. Twenty-four patients had undergone fCurA/B (R0) surgery in these 25 patients. In comparison with the patients who did not survive for 5 years, the long-term survivors had fewer metastatic lymph nodes, that is, up to three (p = 0.0028). In regard to the impact of lymph node metastasis, the prognostic factor was the number of lymph nodes (3-year overall survival, 0 or 1: 68.1% vs >2: 40.0%, p = 0.0304).

CONCLUSION

For obtaining long-term survival, curative resection would be necessary in patients with no more than one lymph node metastasis.

[Positron tomography with 18F-fluorodeoxyglucose in the preoperative evaluation of gall bladder lesions suspicious of malignancy. Diagnostic utility and clinical impact]

BACKGROUND

Gallbladder carcinoma is a neoplasm having a poor prognosis in which the role of the positron emission tomography with (18)F-fluordeoxyglucose as a diagnostic tool, although of possible usefulness, has not been well-defined.

METHODS/DESIGN

It is a prospective cohort of patients with radiologically malignant suspicious gallbladder lesions. A staging diagnostic presurgical FDG-PET study was carried out in each patient using both dedicated PET and multimodality PET-CT scanners. Diagnostic accuracy parameters were calculated from the results of PET imaging and were correlated with the condition and/or the clinical course of the patients. The clinical impact of its implementation in the diagnosis of gallbladder carcinoma was also analyzed.

RESULTS

A total of 42 patients were recruited (22 malignant lesions, 20 benign). Overall diagnostic accuracy was 83.33% for the diagnosis of the primary lesion, 88.89% for the evaluation of lymph node involvement and 85.1% for the evaluation of metastatic disease. Mean SUVmax in malignant gallbladder lesions was 6.14±2.89. ROC curve showed a cut-off value of 3.65 in the SUVmax for malignancy. Accuracy of PET studies alone (n=21) was slightly lower than that of the PET/CT (n=21). FDG-PET changed the management of 14.8% of the population due to the identification of unsuspected metastatic disease.

COMMENTS

FDG-PET accurately diagnoses malignancy or benignity of suspicious gallbladder lesions, with the addition of its capacity to identify unsuspected metastatic disease. PET-CT improves the diagnostic accuracy of the procedure, due to the metabolic-structural complementarity of their information. The SUVmax has a complementary value added to the visual analysis.

Endoscopic diagnosis of extrahepatic bile duct carcinoma: Advances and current limitations

The accurate diagnosis of extrahepatic bile duct carcinoma is difficult, even now. When ultrasonography (US) shows dilatation of the bile duct, magnetic resonance cholangiopancreatography followed by endoscopic US (EUS) is the next step. When US or EUS shows localized bile duct wall thickening, endoscopic retrograde cholangiopancreatography should be conducted with intraductal US (IDUS) and forceps biopsy. Fluorescence in situ hybridization increases the sensitivity of brush cytology with similar specificity. In patients with papillary type bile duct carcinoma, three biopsies are sufficient. In patients with nodular or infiltrating-type bile duct carcinoma, multiple biopsies are warranted, and IDUS can compensate for the limitations of biopsies. In preoperative staging, the combination of dynamic multi-detector low computed tomography (MDCT) and IDUS is useful for evaluating vascular invasion and cancer depth infiltration. However, assessment of lymph nodes metastases is difficult. In resectable cases, assessment of longitudinal cancer spread is important. The combination of IDUS and MDCT is useful for revealing submucosal cancer extension, which is common in hilar cholangiocarcinoma. To estimate the mucosal extension, which is common in extrahepatic bile duct carcinoma, the combination of IDUS and cholangioscopy is required. The utility of current peroral cholangioscopy is limited by the maneuverability of the “baby scope”. A new baby scope (10 Fr), called “SpyGlass” has potential, if the image quality can be improved. Since extrahepatic bile duct carcinoma is common in the Far East, many researchers in Japan and Korea contributed these studies, especially, in the evaluation of longitudinal cancer extension.

Preoperative diagnosis of lymph node metastasis in biliary and pancreatic carcinomas: evaluation of the combination of multi-detector CT and serum CA19-9 level

BACKGROUND

It is difficult to diagnose lymph node metastasis in biliary and pancreas carcinomas before surgery.

AIM

The aim of this study was to assess the utility of the combination of multi-detector computed tomographic (MDCT) findings and serum carbohydrate antigen (CA)19-9 level in the diagnosis of lymph node metastasis in biliary and pancreas carcinomas.

METHODS

The subjects were 139 patients with biliary and pancreas carcinomas who underwent surgical resection. We calculated the positive predictive values (PPV), sensitivities, specificities, positive likelihood ratios (PLR) and accuracies of diagnosis by MDCT alone, serum CA19-9 level alone, and their combination.

RESULTS

The PPV and sensitivity were higher for node metastasis in hepatoduodenal ligament than in common hepatic artery (CHA) or para-aortic region (PAR). Specificity, accuracy and PLR were highest for CHA in biliary carcinoma. With pancreatic carcinoma, PLR was slightly higher in PAR compared to other regions. The sensitivity of CA19-9 for node metastasis was higher than that of MDCT, while the PPV, specificity, accuracy and PLR were low for both biliary and pancreas carcinoma. The combination of positive CT findings and high CA19-9 level had the highest positive rate for node metastasis for both types of carcinomas. Nodes around the supra-mesenteric vein could not be fully observed on CT.

CONCLUSION

The combination of high-resolution MDCT and CA19-9 is useful for the diagnosis of lymph node metastasis in biliary and pancreas carcinomas.

Successful left hemihepatectomy and perioperative management of a patient with biliary cystadenocarcinoma, complicated with MELAS syndrome: report of a case

Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like syndrome (MELAS) is a rare, fetal disease caused by a mutation in mitochondrial DNA that leads to impaired oxidative metabolism in skeletal muscle, the central nervous system, and liver function. This report presents the case of a 50-year-old woman with biliary cystadenocarcinoma complicated by MELAS who underwent a successful left hemihepatectomy. In this case, the diagnostic key for the malignant tumor was an (18)F-fluorodeoxyglucose positron emission tomography study, which was useful even in a patient with MELAS, which causes abnormal glucose metabolism. The perioperative management of such patients includes special precautions to prevent lactic acidosis and deterioration of the reserved liver function after a hepatectomy, since the mitochondrial function in MELAS patients is abnormal. The patient in this report has remained free of liver dysfunctions and cancer recurrence for 2 years following the hepatectomy. This is the first report of a successful major hepatectomy for a patient with MELAS.

Prognostic importance of standardized uptake value on F-18 fluorodeoxyglucose-positron emission tomography in biliary tract carcinoma

BACKGROUND AND OBJECTIVES

F-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) has been used for diagnosis and staging of malignant diseases. However, the prognostic significance of FDG uptake on PET had not been sufficiently evaluated in patients with biliary carcinoma.

METHODS

We performed a retrospective review of patients with biliary carcinoma imaged by FDG-PET to determine whether high uptake of FDG predicted overall survival independently of clinicopathological characteristics. Sixty-nine patients with biliary carcinoma underwent FDG-PET before cancer treatment. The maximum standard uptake value (maxSUV) was calculated as an index of FDG uptake.

RESULTS

A receiver operating characteristic curve demonstrated a maxSUV of 6.3 to be the optimal cutoff point. The 3-year survival rate of patients with a maxSUV of 6.3 or less was 74.3%, whereas it was 44.1% for those with values greater than 6.3. Univariate analysis showed that the maxSUV was one of the significant prognostic factors for overall survival (P = 0.0119), whereas multivariate analysis showed that the independent predictors of survival were pN, pM, and pTNM staging.

CONCLUSIONS

SUV analysis of FDG-PET was useful to predict the prognosis of biliary carcinoma. This information may assist in the guiding of treatment strategies before postoperative pathological assessment.