Positron-emission tomography with fluorine-18-fluoro-2-deoxy-D-glucose for gallbladder cancer diagnosis

Quarter-Century PET/Computed Tomography Transformation of Oncology: Hepatobiliary and Pancreatic Cancer

[18F] Fluorodeoxyglucose (18F-FDG) PET/CT can improve the staging accuracy and clinical management of patients with hepatobiliary and pancreatic cancers, by detection of unsuspected metastases. 18F-FDG PET/CT metabolic parameters are valuable in predicting treatment response and survival. Metabolic response on 18F-FDG PET/CT can predict preoperative pathologic response to neoadjuvant therapy in patients with pancreatic cancer and determine prognosis. Several novel non-FDG tracers, such as 68Ga prostate-specific membrane antigen (PSMA) and 68Ga-fibroblast activation protein inhibitor (FAPI) PET/CT, show promise for imaging hepatobiliary and pancreatic cancers with potential for radioligand therapy.

Imaging update on gallbladder adenomyomatosis and its mimics

Radiologists across many imaging modalities commonly encounter gallbladder adenomyomatosis. The classic imaging appearances of gallbladder adenomyomatosis are well described and confirm benignity. However, in clinical practice, adenomyomatosis can be challenging to differentiate from other gallbladder pathologies that require cholecystectomy. In this article, we describe the common and uncommon appearances of gallbladder adenomyomatosis on multimodality imaging, helping differentiate adenomyomatosis from non-benign gallbladder abnormalities. Accurately differentiating adenomyomatosis from its mimics provides the surgical team with important clinical and surgical management information, improving patient outcomes.

Xanthogranulomatous cholecystitis in a patient with ulcerative colitis and primary sclerosing cholangitis: A case report

Chronic gallbladder disease due to xanthogranulomatous cholecystitis is uncommon, and its symptoms are generally vague. While there is no firm evidence to link xanthogranulomatous cholecystitis to primary sclerosing cholangitis or ulcerative colitis. The patient is a 41-year-old male with a history of ulcerative colitis, primary sclerosing cholangitis, and biliary stenting who complained of symptoms of anorexia, jaundice, and pruritus. In the initial ultrasound exam, there was evidence of intrahepatic and extra-hepatic bile duct dilation along with a significant and mass-like circumferential thickening of the gallbladder wall. Magnetic resonance cholangiopancreatography was performed for further evaluation, which indicated increased gallbladder wall thickness, containing multiple T2 hyper-signal nodules while the mucosal layer was intact. There was also a filling defect in the common bile duct's distal portion. These findings matched a xanthogranulomatous cholecystitis diagnosis and a possibly malignant lesion in the distal of the common bile duct. The patient ultimately had a cholecystectomy, and pathology findings confirmed the diagnosis of xanthogranulomatous cholecystitis. Biopsy specimens obtained from the distal of the common bile duct lesion were microscopically identified as intramucosal adenocarcinoma. In patients with a history of primary sclerosing cholangitis who present with nonspecific symptoms suggesting chronic gallbladder disease and radiologic evidence of circumferential gallbladder wall thickening containing intramural nodules and intact mucosa, xanthogranulomatous cholecystitis should be kept in mind.

Spectrum of imaging findings in hyperplastic cholecystosis and potential mimics

Adenomyomatosis and cholesterolosis of the gallbladder, collectively termed hyperplastic cholecystosis, are commonly encountered incidental findings on imaging studies performed for a variety of indications including biliary colic or nonspecific abdominal pain. These pathologies are rarely the source of symptoms, generally considered benign and do not require further work-up. However, their imaging characteristics can overlap with more sinister conditions that should not be missed. In this review, the imaging findings of adenomyomatosis and cholesterolosis will be reviewed followed by other gallbladder pathologies that might mimic these conditions radiologically. Important differentiating factors will be discussed that can aid the radiologist in making a more confident imaging diagnosis.

The Diagnostic Accuracy of 18F-FGD-PET/CT for Cancer of the Gallbladder: A Retrospective Study

Background  Gallbladder cancer has a poor prognosis and imaging can have variable diagnostic accuracy. We assessed the ability of preoperative ¹⁸ F-fluorodeoxyglucose positron emission tomography computed tomography ( ¹⁸ F-FDG-PET/CT) imaging to predict a postoperative histological diagnosis of gallbladder cancer.

Method  A retrospective analysis was undertaken in a cohort of patients, who had suspected gallbladder cancer on cross-sectional imaging and that underwent preoperative FDG-PET/CT scan. The discriminatory power of FDG-PET/CT was determined in receiver operator characteristic (ROC) analysis and diagnostic accuracy parameters were estimated at different thresholds of maximum standard unit value (SUV _max ) _.

Results  Twenty-two patients were included in the study; 7 had malignant and 15 benign diagnoses. There was no statistically significant difference between the measured SUV _max between the two groups ( p  = 0.71). With an area under the curve of 0.486, the ROC curve did not indicate any discriminatory power of FDG-PET/CT at any potential threshold of SUV _max.

Conclusion  This study indicates that the diagnosis of primary gallbladder cancer cannot be accurately confirmed with FDG PET/CT scanning.

Malignant Lymphoma Diagnosed as Gallbladder Carcinoma on 18F-FDG PET/CT

ABSTRACT

Extranodal primary lymphoma of gallbladder is extremely rare. We report a 48-year-old woman initially diagnosed as gallbladder carcinoma with lymph nodes metastases by contrast-enhanced CT and MRI. Meanwhile the images of 18F-FDG PET/CT highly suggested gallbladder carcinoma due to the necrosis in one of the enlarged lymph nodes. However, it was proved to be diffuse large B-cell lymphoma by the histopathological diagnosis.

Current update on gallbladder carcinoma

Gallbladder (GB) carcinoma is a relatively rare malignancy and is associated with poor prognosis. Numerous risk factors have been associated with the development of GB carcinoma. GB carcinomas may present as mass lesions replacing the GB, focal or diffuse thickening of the GB wall, and intraluminal mass in the GB. Various benign conditions can mimic GB carcinoma. This article reviews the epidemiology, pathology, clinical findings, imaging features, and management of GB carcinomas.

NIR/photoacoustic imaging of multitype gallbladder cancer using carboxyl/amino functionalized polymer dots

Gallbladder cancer has high incidence and mortality and a low early diagnosis rate and requires rapid and efficient diagnosis. Herein, carboxyl/amino functionalized polymer dots (Pdots) were designed to enhance cellular internalization and tumor accumulation. The prepared Pdots were 40-50 nm in diameter, contained no toxic metal, exhibited long circulation time and high stability, and produced strong NIR emission and photoacoustic signals. Different cellular uptake and distribution of functionalized Pdots in eight gallbladder cell lines were quantitatively investigated using flow cytometry and super-resolution microscopy. In vivo NIR fluorescence imaging showed that the functional Pdots had high accumulation in the tumor after 30 minutes of injection and remained there for up to 6 days. In addition, photoacoustic imaging found that the abundant blood vessels around the tumor microenvironment and Pdots entered the tumor through the blood vessels. Furthermore, a high heterogeneity of vascular networks was visualized in real-time and high resolution by probe-based confocal laser endomicroscopy imaging. These results offer a new avenue for the development of functional Pdots as a probe for multi-modal and multi-scale imaging of gallbladder cancer in small animals.

Imaging-based algorithmic approach to gallbladder wall thickening

Gallbladder (GB) wall thickening is a frequent finding caused by a spectrum of conditions. It is observed in many extracholecystic as well as intrinsic GB conditions. GB wall thickening can either be diffuse or focal. Diffuse wall thickening is a secondary occurrence in both extrinsic and intrinsic pathologies of GB, whereas, focal wall thickening is mostly associated with intrinsic GB pathologies. In the absence of specific clinical features, accurate etiological diagnosis can be challenging. The survival rate in GB carcinoma (GBC) can be improved if it is diagnosed at an early stage, especially when the tumor is confined to the wall. The pattern of wall thickening in GBC is often confused with benign diseases, especially chronic cholecystitis, xanthogranulomatous cholecystitis, and adenomyomatosis. Early recognition and differentiation of these conditions can improve the prognosis. In this minireview, the authors describe the patterns of abnormalities on various imaging modalities (conventional as well as advanced) for the diagnosis of GB wall thickening. This paper also illustrates an algorithmic approach for the etiological diagnosis of GB wall thickening and suggests a formatted reporting for GB wall abnormalities.

Radio-pathological Correlation of 18F-FDG PET in Characterizing Gallbladder Wall Thickening

AIM

Thick-walled gallbladder is difficult to characterize on conventional imaging. 18F-FDG PET was used to differentiate benign and malignant wall thickness and compared with histopathology.

METHODS

Thirty patients with gallbladder (GB) wall thickening (focal > 4 mm and diffuse > 7 mm), underwents uspected on  ultrasound, or CT scan, and underwent 18F-FDG PET. Histopathology of the specimen was compared with imaging findings.

RESULTS

The mean age was 48.22 ± 31.33 years with a M:F 1:4 ratio. Twenty patients had diffuse and 10 had focal thickening. On 18F-FDG PET, lesion was benign in 12, malignant in 13, and indeterminate in 5. Histopathology was malignancy in 12; benign in 18-chronic cholecystitis in 11, xanthogranulomatous in 4, IgG4 related in 2, and polyp in 1. The mean GB wall thickness was 7.79 ± 3.59 mm (10.34 malignant and 6.10 in benign, p = 0.001). At a cutoff of 8.5 mm, the sensitivity and specificity of detecting malignancy was 94% and 67%. The mean SUV uptake was 7.46 (benign 4.51, malignant 14.26, p = 0.0102). At a cutoff of 5.95, the sensitivity and specificity of detecting malignancy was 92% and 79%. For 18F-FDG PET, overall sensitivity was 91%, specificity 79%, PPV 77%, NPV 92%, and diagnostic accuracy was 84%.

CONCLUSION

18F-FDG PET is a reliable method of differentiation between benign and malignant thickening of the gallbladder particularly when wall thickness and SUV value is taken into account.

The Utility of PET/Computed Tomography for Radiation Oncology Planning, Surveillance, and Prognosis Prediction of Gastrointestinal Tumors

At present, the strongest evidence for the use of PET/computed tomography (CT) in gastrointestinal (GI) malignancies is to rule out distant metastatic disease at diagnosis, radiation treatment planning for anal malignancies, and disease recurrence monitoring in colorectal and anal malignancies. Use of PET/CT for GI malignancies continues to evolve over time, with new studies evaluating prognostic abilities of PET/CT and with increasing sensitivity and spatial resolution of more modern PET/CT scanners. The authors encourage future applications and prospective evaluation of the use of PET/CT in the staging, prognostication, and recurrence prediction for GI malignancies.

18F-fluorodeoxyglucose positron emission tomography (18FDG-PET) for patients with biliary tract cancer: Systematic review and meta-analysis

BACKGROUND & AIMS

The role of ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸FDG-PET) in the diagnosis and staging of patients with biliary tract cancers (BTCs) remains controversial, so we aimed to provide robust information on the utility of ¹⁸FDG-PET in the diagnosis and management of BTC.

METHODS

This systematic review and meta-analysis explored the diagnostic test accuracy of ¹⁸FDG-PET as a diagnostic tool for diagnosis of primary tumour, lymph node invasion, distant metastases and relapsed disease. Subgroup analysis by study quality and BTC subtype were performed. Changes in management based on ¹⁸FDG-PET and impact of maximum standardised uptake values (SUVmax) on prognosis were also assessed. A random effects model was used for meta-analyses.

RESULTS

A total of 2,125 patients were included from 47 eligible studies. The sensitivity (Se) and specificity (Sp) of ¹⁸FDG-PET for the diagnosis of primary tumour were 91.7% (95% CI 89.8-93.2) and 51.3% (95% CI 46.4-56.2), respectively, with an area under the curve (AUC) of 0.8668. For lymph node invasion, Se was 88.4% (95% CI82.6-92.8) and Sp was 69.1% (95% CI 63.8-74.1); AUC 0.8519. For distant metastases, Se was 85.4% (95% CI 79.5-90.2) and Sp was 89.7% (95% CI86.0-92.7); AUC 0.9253. For relapse, Se was 90.1% (95% CI 84.4-94.3) and Sp was 83.5% (95% CI 74.4-90.4); AUC 0.9592. No diagnostic threshold effect was identified. Meta-regression did not identify significant sources of heterogeneity. Sensitivity analysis revealed no change in results when analyses were limited to studies with low risk of bias/concern. The pooled proportion of change in management was 15% (95% CI 11-20); the majority (78%) due to disease upstaging. Baseline high SUVmax was associated with worse survival (pooled hazard ratio of 1.79; 95% CI 1.37-2.33; p <0.001).

CONCLUSIONS

There is evidence to support the incorporation of ¹⁸FDG-PET into the current standard of care for the staging (lymph node and distant metastases) and identification of relapse in patients with BTC to guide treatment selection; especially if the identification of occult sites of disease would change management, or if diagnosis of relapse remains unclear following standard of care imaging. The role for diagnosis of the primary tumour remains controversial due to low sensitivity and ¹⁸FDG-PET should not be considered as a replacement for pathological confirmation in this setting.

LAY SUMMARY

A positron emission tomography (PET scan), using ¹⁸F-fluorodeoxyglucose (¹⁸FDG), can help doctors identify areas of cancer in the body by highlighting "hot spots". These hotspots may be cancerous (true positive) but may also be non-cancerous, like inflammation (false positive). We show that PET scans are useful to assess how far advanced the cancer is (by assessing spread to lymph glands and to other organs) and also to identify if the cancer has recurred (for example after surgery), thus helping doctors to make treatment decisions. However, a biopsy is still needed for the initial diagnosis of a biliary tract cancer, because of the high chance of a "false positive" with PET scans.

Cross-sectional Imaging of Gallbladder Carcinoma: An Update

Gallbladder Carcinoma (GBCA) is the most common biliary tract malignancy. As the disease is often diagnosed clinically in an advanced stage, the survival rates are dismal. Imaging studies allow for an early diagnosis of malignancy, though the findings may be indistinguishable from non-malignant disease processes affecting the gallbladder. Attempts have been made to make a specific diagnosis of GBCA at an early stage on imaging studies. Ultrasonography (US) is the most commonly employed technique for gallbladder evaluation. Gallbladder wall thickening is the most common finding of early GBCA and in this context, US is non-specific. Recently, contrast enhanced ultrasound has been shown to be effective in differentiating benign from malignant disease. Multidetector computed tomography represents the most robust imaging technique in evaluation of GBCA. It provides relatively sensitive evaluation of mural thickening, though it is not entirely specific and issues in differentiating GBCA from xanthogranulomatous cholecystitis do arise. Due to its superior soft tissue resolution, Magnetic Resonance Imaging (MRI) provides excellent delineation of gallbladder and biliary tree involvement. When coupled with functional MRI techniques, such as diffusion-weighted and perfusion imaging, it provides a useful problem solving tool for interrogating the malignant potential of nonspecific gallbladder lesions and detection of metastases. Positron emission tomography has a role in detection of distant metastases and following patients following treatment for malignancy. We review the current role of various imaging modalities in evaluating patients with GBCA.

Strategies for Differentiating Gallbladder Carcinoma from Xanthogranulomatous Cholecystitis-a Tertiary Care Centre Experience

Xanthogranulomatous cholecystitis (XGC) is an uncommon variant of chronic cholecystitis, characterized by focal or diffuse destructive inflammatory process. The importance of XGC is that it mimics gallbladder carcinoma (GBC) both preoperatively and intra-operatively, since it can present with pericholecystic infiltration, hepatic involvement and lymphadenopathy. As a result of this misdiagnosis which is not infrequent, the patient may need to undergo an unnecessary radical cholecystectomy rather than only a cholecystectomy which is associated with greater morbidity and mortality. Patients who underwent gallbladder and gallbladder-related operations during period of 5 years between 2010 and 2014 were reviewed (n = 462). A comparison of clinical, biochemical, radiological and operative features were made between patients with carcinoma gallbladder (n = 101) and xanthogranulomatous cholecystitis (n = 22). Patient with a long history of recurrent abdominal pain with leucocytosis and who on imaging are found to have a diffusely thickened gallbladder wall (p < 0.01), with cholelithiasis, choledocholithiasis and sub-mucosal hypoattenuated nodules (p < 0.05) are likely to have XGC while those with anorexia, weight loss, focal thickening of the gallbladder wall on imaging (p < 0.01) and dense local organ infiltration are more likely to have GBC. The presence of lymph nodes on imaging and the loss of fat plane interface between the liver and gallbladder are not differentiating factors. Differentiating XGC from GBC in preoperative setting is necessary to avoid radical procedures being done for a benign process. Certain clinical, radiological and intra-operative features aid in differentiating these benign and malignant process. However, the definitive diagnosis still remains a histopathological examination to avoid radical resection in patients who have a benign condition.

A case report of wound site seeding following cholecystectomy for dysplastic gallbladder

Wound site metastasis following cholecystectomy is an uncommon but well recognised complication following laparoscopic surgery for unsuspected gallbladder carcinoma. We describe a case of implantation of dysplastic cells with subsequent malignant transformation at the incision site 3 years post-cholecystectomy for an inflamed gallbladder. Histopathological examination of this tumour confirmed adenocarcinoma of pancreatobiliary origin, possibly secondary to gallbladder cells implantation and subsequent carcinomatous change. Unlike previously reported cases, the present case has two unique features: Firstly, the histology of the resected gallbladder at the initial operation was that of a low-grade dysplasia and not carcinoma; and secondly, there was a long interval between initial surgery and subsequent development of the wound site tumour. This case highlights that careful handling of the specimen tissue intraoperatively is paramount as cells implanted in the wound site can survive and undergo malignant transformation. All new masses occurring along the surgical wound site should be followed up and investigated to exclude implanted tumours.

Fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography for the detection of proximal synchronous lesions in patients with obstructive colorectal cancer

BACKGROUND AND AIM

We aimed to investigate the ability of fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) to detect synchronous neoplasms, specifically obstructive colorectal cancer (CRC) and CRC in the proximal colon and to suggest a management strategy based on FDG PET/CT findings.

METHODS

From the CRC surgery database of our institution, 518 patients with obstructive CRC whose proximal colon could not be examined by colonoscopy and who underwent preoperative FDG PET/CT were eligible for this study. Of these, final analyses were performed in 345 patients who had reference standards for the proximal colon, which were a surgical colectomy specimen and/or postsurgical colonoscopy. The per-patient and per-lesion performances of FDG PET/CT for synchronous CRC diagnosis were determined.

RESULTS

Of 345 patients, 14 (4.1%) had 14 proximal synchronous CRCs. Thirty-four patients showed 39 areas of abnormal FDG uptake on PET/CT in the colon proximal to the obstructive CRC. PET/CT detected all of the 14 proximal synchronous CRCs. The per-patient PET/CT sensitivity, specificity, positive predictive value, and negative predictive value for proximal synchronous CRC were 100%, 93.9%, 41.2%, and 100%, respectively. Per-lesion values were 100%, 92.6%, 35.9%, and 100%, respectively. The per-lesion sensitivity and negative predictive value of PET/CT for advanced adenoma were 45.5% and 92.7%, respectively.

CONCLUSIONS

The FDG PET/CT shows a high sensitivity and negative predictive value for the detection of proximal synchronous CRC in patients with obstructive CRC, enabling negative findings in the proximal colon on PET/CT to definitively exclude proximal synchronous CRC. Preoperative PET/CT recommended to determine the proper surgical plan in patients with obstructive CRC.

Technical Aspects of Gallbladder Cancer Surgery

In this review, the authors present an updated description of gallbladder cancer in 2 sections based on presentation: disease that presents incidentally following laparoscopic cholecystectomy and malignancy that is suspected preoperatively. Elements pertaining to technical aspects of surgical resection provide the critical focus of this review and are discussed in the context of evidence-based literature on gallbladder cancer today.

Role of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography in gastrointestinal cancers

Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) has become a routine imaging modality for many malignancies and its use is currently increasing. In the present review article, we will summarize the evidence for FDG-PET/CT use in digestive cancers (excluding neuroendocrine tumours), and review the existing recommendations. While PET/CT is nowadays considered to be an important tool in the initial workup of oesophageal and anal cancers, new data are emerging regarding its use in assessing therapeutic efficacy, radiotherapy treatment planning, and detection of recurrence in case of isolated tumour marker elevation. Moreover, PET/CT may help decision making by detecting distant metastatic sites especially in potentially resectable metastatic colorectal cancer and, to a lesser extent, in localized gastric and pancreatic cancers. Finally, incidental focal colonic FDG uptakes require exploration by colonoscopy, as they are often associated with premalignant or malignant lesions.

Expression of GLUT-1 and GLUT-3 in xanthogranulomatous cholecystitis induced a positive result on ¹⁸F-FDG PET: report of a case

Although several reports have revealed that fluorine-18 fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) is useful for differentiating between benign and malignant lesions in the gallbladder, the positive results of (18)F-FDG PET are not specific for malignancy because (18)F-FDG is also accumulated in inflammatory lesions. It is known that the most important pathway for (18)F-FDG to enter the cell body is mediated by the facilitative glucose transporter-1 (GLUT-1) through GLUT-3. We herein present a case of xanthogranulomatous cholecystitis (XGC) with a positive result on (18)F-FDG PET. In this case, GLUT-1 and GLUT-3 were both positively expressed in inflammatory cells at the gallbladder wall of XGC and this is the first report to reveal GLUT expression in XGC. This report reveals that surgeons should carefully consider the appropriate treatment of gallbladder tumor, even with a positive result on (18)F-FDG PET.

Impact of pre-operative positron emission tomography in gallbladder cancer

BACKGROUND

Current pre-operative staging methods for gallbladder cancer (GBC) are suboptimal in detecting metastatic disease. Positron emission tomography (PET) may have a role but data are lacking.

METHODS

Patients with GBC and PET assessed by a hepatobiliary surgeon in clinic between January 2001 and June 2013 were retrospectively reviewed. Computed tomography (CT)/magnetic resonace imaging (MRI) were correlated with PET scans and analysed for evidence of metastatic or locally unresectable disease. Medical records were reviewed to determine if PET scanning was helpful by preventing non-therapeutic surgery or enabling resection in patients initially deemed unresectable.

RESULTS

There were 100 patients including 63 incidental GBC. Thirty-eight patients did not proceed to surgery, 35 were resected and 27 patients were explored but had unresectable disease. PET was positive for metastatic disease in 39 patients (sensitivity 56%, specificity 94%). Five patients definitively benefitted from PET: in 3 patients PET found disease not seen on CT, and 2 patients with suspicious CT findings had negative PET and successful resections. In a further 12 patients PET confirmed equivocal CT findings. Three patients had additional invasive procedures performed owing to PET avidity in other sites. Utility of PET was higher in patients with suspicious nodal disease on CT [odds ratio (OR) 7.1 versus no nodal disease, P = 0.0004], and in patients without a prior cholecystectomy (OR 3.1 versus post-cholecystectomy, P = 0.04).

CONCLUSION

Addition of PET to conventional cross-sectional imaging has a modest impact on management pre-operatively particularly in patients without a prior cholecystectomy and to confirm suspicious nodal disease on CT.

Xanthogranulomatous cholecystitis: a European and global perspective

INTRODUCTION

Xanthogranulomatous cholecystitis (XGC) is often mistaken for, and may predispose to, gallbladder carcinoma (GB Ca). This study reviews the worldwide variation of the incidence, investigations, management and outcome of patients with XGC.

METHODS

Data from 29 studies, cumulatively containing 1599 patients, were reviewed and results summarized by geographical region (Europe, India, Far East and Americas) with 95% confidence intervals (CIs) to present variability within regions. The main study outcomes were incidence, association with GB Ca and treatment of patients with XGC.

RESULTS

Overall, the incidence of XGC was 1.3-1.9%, with the exception of India where it was 8.8%. The incidence of GB Ca associated with XGC was lowest in European studies (3.3%) varying from 5.1-5.9% in the remaining regions. Confusion with or undiagnosed GB Ca led to 10.2% of patients receiving over or under treatment.

CONCLUSIONS

XGC is a global disease and is associated with GB Ca. Characteristic pathological, radiological and clinical features are shared with GB Ca and contribute to considerable treatment inaccuracy. Tissue sampling by pre-operative endoscopic ultrasound or intra-operative frozen section is required to accurately diagnose gallbladder pathology and should be performed before any extensive resection is performed.

Is there any role of positron emission tomography computed tomography for predicting resectability of gallbladder cancer?

The role of integrated (18)F-2-fluoro-2-deoxy-D-glucose positron emission tomography computed tomography (PET-CT) is uncertain in gallbladder cancer. The aim of this study was to show the role of PET-CT in gallbladder cancer patients. Fifty-three patients with gallbladder cancer underwent preoperative computed tomography (CT) and PET-CT scans. Their medical records were retrospectively reviewed. Twenty-six patients underwent resection. Based on the final outcomes, PET-CT was in good agreement (0.61 to 0.80) with resectability whereas CT was in acceptable agreement (0.41 to 0.60) with resectability. When the diagnostic accuracy of the predictions for resectability was calculated with the ROC curve, the accuracy of PET-CT was higher than that of CT in patients who underwent surgical resection (P=0.03), however, there was no difference with all patients (P=0.12). CT and PET-CT had a discrepancy in assessing curative resection in nine patients. These consisted of two false negative and four false positive CT results (11.3%) and three false negative PET-CT results (5.1%). PET-CT was in good agreement with the final outcomes compared to CT. As a complementary role of PEC-CT to CT, PET-CT tended to show better prediction about resectability than CT, especially due to unexpected distant metastasis.

Ability of FDG-PET/CT in the detection of gallbladder cancer

PURPOSE

To assess the value of FDG-PET/CT in the evaluation of gallbladder carcinomas (GBC).

METHODS

A prospective cohort of patients with suspicion of or confirmed GBC was studied with FDG-PET/CT. Diagnostic accuracy parameters were calculated in comparison with pathology and/or the clinical course of patients. Clinical impact of PET/CT imaging was estimated.

RESULTS

Forty-nine patients were enrolled (34 malignant tumors, 15 benign lesions; 37 staging, 12 restaging). Overall diagnostic accuracy was 95.9% for the diagnosis of the primary lesion, 85.7% for lymph node involvement and 95.9% for metastatic disease. Mean SUVmax in malignant gallbladder lesions was 7.92 ± 6.25 Analysis of ROC curves showed a SUVmax cut-off value of 3.62 for malignancy (S: 78.1%; Sp: 88.2%). Diagnostic accuracy in the restaging group reached 100%. FDG-PET/CT changed the management of 22.4% of the population.

COMMENTS

Diagnosis of malignancy or benignity of suspicious gallbladder lesions is accurately made with FDG PET/CT, allowing a precise staging of GBC due to its ability to identify unsuspected metastatic disease. SUVmax has a complementary role in addition to visual analysis.

Clinical impact of FDG PET-CT on management decisions for patients with primary biliary tumours

Objectives

To assess the impact on clinical management of introducing ¹⁸F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET)-computed tomography (CT) in to the work-up of patients with primary and recurrent biliary malignancy.

Methods

Consecutive patients with primary biliary tumours undergoing FDG PET-CT at a single large tertiary referral centre between November 2007 and September 2010 were retrospectively analysed. Findings on FDG PET-CT compared with CT/magnetic resonance imaging (MRI) and impact on subsequent patient management were evaluated. Impact was divided into: (1) major—detection of occult disease or characterisation of indeterminate lesion(s) on CT/MRI; (2) minor—confirmation of suspected metastases seen on CT/MRI; (3) no impact.

Results

One hundred and eleven patients underwent 118 FDG PET-CT scans, including 30 with suspected gallbladder carcinoma and 81 with cholangiocarcinoma. Eighty-nine scans were performed for initial staging, five for restaging following neoadjuvant chemotherapy and 24 for suspected disease recurrence. In 33 cases (28 %), FDG PET-CT had a major impact on subsequent patient management (39 % gallbladder carcinoma, 26 % intrahepatic cholangiocarcinoma and 21 % extrahepatic cholangiocarcinoma). FDG PET-CT had a minor impact in 20 cases (17 %) and no impact in 65 cases (55 %).

Conclusions

By detecting occult metastatic disease and characterising indeterminate lesions, FDG PET-CT can have a major influence on clinical decision-making in primary and recurrent biliary malignancy.

Mycobacterial infection of the gallbladder masquerading as gallbladder cancer with a false positive pet scan

Isolated mycobacterial infection of gall bladder is an extremely rare entity. Only anecdotal reports are evident in the literature. A preoperative diagnosis of mycobacterial infection of gallbladder is therefore very difficult. The case of a 72-year-old male who underwent surgery for suspected gallbladder cancer is presented. The diagnosis of cancer was based on radiological findings and an abnormal uptake of fluorine-18-fluoro-2-deoxy-D-glucose (FDG) on positron emission tomography (PET) scan whilst being followed up for colorectal cancer. He underwent cholecystectomy and gallbladder bed resection. Histopathology was consistent with mycobacterial infection of the gallbladder.

Role of 18F-FDG PET/CT in detecting recurrent gallbladder carcinoma

AIM

The present study was aimed to determine the efficacy of integrated FDG PET/CT in patients with gallbladder cancer (GBC) with suspicion of recurrent disease.

METHODS

A total of 49 patients (male: 15, female: 34; median age: 52.5 years) with GBC underwent FDG PET/CT for suspected recurrence. A total of 62 PET/CT scans were acquired. Criteria for detection by PET/CT were both a positive FDG uptake and the correct anatomic localization of the tumor. The PET/CT findings were grouped as locoregional disease and metastatic disease. Results of PET/CT were compared with clinical and radiologic follow-up and/or histopathology. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated. Results of PET/CT were also compared with conventional imaging (CI) whenever available.

RESULTS

Of 62 PET/CT, 43 (69.4%) were positive and 19 (30.6%) were negative for recurrence. Of 43 positive scans, 41 were true positive and 2 were false positive. Among 19 negative PET/CT scans, 18 were true negative and 1 was false negative. PET/CT showed a sensitivity of 97.6% and specificity of 90% in detecting tumor recurrence. The positive predictive value, negative predictive value, and accuracy were 95.3%, 94.7%, and 95.1%, respectively. Locoregional disease was seen in 16 (37.2%) PET/CT studies, distant metastases were seen in 13 (30.2%), and 14 (32.5%) studies showed both locoregional disease and metastasis. When comparable CI was available, PET/CT showed a better specificity than CI for detection of recurrence.

CONCLUSIONS

Integrated FDG PET/CT can detect recurrence in GBC with high sensitivity and specificity. Routine use of PET/CT in these patients will detect recurrence early and change the subsequent management.

Positron emission tomography in hepatobiliary and pancreatic malignancies: a review

BACKGROUND

The prognosis for hepatobiliary and pancreatic malignancies is dismal. Surgery remains the primary curative option, but unresectable disease is often discovered during operative exploration. Positron emission tomography (PET) provides unique biological information different from current imaging modalities. The role of PET in detecting hepatobiliary and pancreatic malignancies has not yet been established. The purpose of this article was to review the literature on the use of PET in hepatobiliary and pancreatic malignancies.

DATA SOURCES

We performed an extensive search on PubMed using PET and hepatocellular, pancreatic, gallbladder, and cholangiocarcinoma as keywords, excluding articles not written in English or on nonhuman subjects, case reports, and series with <5 patients.

CONCLUSIONS

Although PET has shown usefulness in the diagnosis of certain cancers, current literature cautions against the use of PET for determining malignant potential of primary liver and pancreatic lesions. Literature on PET more strongly supports clinical roles for restaging of hepatobiliary and pancreatic malignancies, and for identifying metastatic disease.

Risk stratification of gallbladder polyps (1-2 cm) for surgical intervention with 18F-FDG PET/CT

We assessed the value of (18)F-FDG uptake in the gallbladder polyp (GP) in risk stratification for surgical intervention and the optimal cutoff level of the parameters derived from GP (18)F-FDG uptake for differentiating malignant from benign etiologies in a select, homogeneous group of patients with 1- to 2-cm GPs.

METHODS

Fifty patients with 1- to 2-cm GPs incidentally found on the CT portion of PET/CT were retrospectively analyzed. All patients had histologic diagnoses. GP (18)F-FDG activity was visually scored positive (≥liver) or negative (<liver). Maximal standardized uptake value of the GP (SUVgp) and ratio of SUVgp to mean SUV of the liver (GP/L ratio) were also measured. Univariate and multivariate logistic regression analyses were performed to determine the utility of patient and clinical variables--that is, sex, age, gallstone, polyp size, and three (18)F-FDG-related parameters in risk stratification.

RESULTS

Twenty GPs were classified as malignant and 30 as benign. Multivariate analyses showed that the age and all parameters (visual criteria, SUVgp, and GP/L) related to (18)F-FDG uptake were significant risk factors, with the GP/L being the most significant. The sex, size of GPs, and presence of concurrent gallstones were found to be insignificant.

CONCLUSION

(18)F-FDG uptake in a GP is a strong risk factor that can be used to determine the necessity of surgical intervention more effectively than other known risk factors. However, all criteria derived from (18)F-FDG uptake presented in this series may be applicable to the assessment of 1- to 2-cm GPs.

Value of PET/CT in the management of primary hepatobiliary tumors, part 2

OBJECTIVE

Primary hepatobiliary malignancies consist of hepatocellular carcinoma, cholangiocarcinoma, and gallbladder cancer. Benign hepatic lesions include hepatic cysts, hemagiomas, adenomas, and focal nodular hyperplasias. The utility of PET/CT in imaging primary hepatobiliary lesions varies according to the type and location of the lesion.

CONCLUSION

There is a consistent benefit to the use of PET/CT for detection and staging, and it ultimately helps to establish the best course of treatment and to determine prognosis. In addition, PET/CT is very useful in local ablative and systemic therapy assessment and surveillance for hepatobiliary malignancies.

[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.

A role of 18F-fluorodeoxyglucose positron emission/computed tomography in a strategy for abdominal wall metastasis of colorectal mucinous adenocarcinoma developed after laparoscopic surgery

Metastasis to the abdominal wall including port sites after laparoscopic surgery for colorectal cancer is rare. Resection of metastatic lesions may lead to greater survival benefit if the abdominal wall metastasis is the only manifestation of recurrent disease. A 57-year-old man, who underwent laparoscopic surgery for advanced mucinous adenocarcinoma of the cecum 6 years prior, developed a nodule in the surgical wound at the lower right abdomen. Although tumor markers were within normal limits, the metastasis to the abdominal wall and abdominal cavity from the previous cecal cancer was suspected. An abdominal computed tomography scan did not provide detective evidence of metastasis. ¹⁸F-fluorodeoxyglucose positron emission/computed tomography (¹⁸F-FDG PET/CT) was therefore performed, which demonstrated increased ¹⁸F-fluorodeoxyglucose uptake (maximum standardized uptake value: 3.1) in the small abdominal wall nodule alone. Histopathological examination of the resected nodule confirmed the diagnosis of metastatic mucinous adenocarcinoma. Prognosis of intestinal mucinous adenocarcinoma is reported to be poorer than that of non-mucinous adenocarcinoma. In conclusion, this case suggests an important role of ¹⁸F-FDG PET/CT in early diagnosis and decision-making regarding therapy for recurrent disease in cases where a firm diagnosis of recurrent colorectal cancer is difficult to make.

Pericholecystic rim sign on PET/CT secondary to locally invasive gallbladder carcinoma

A variety of gallbladder pathology (eg, carcinoma, acute and chronic cholecystitis, adenomyomatosis, cholestasis) has been imaged with F-18 fluorodeoxyglucose positron emission tomography or positron emission tomography/computed tomography. The pericholecystic rim sign seen on conventional Tc-99m hepatobiliary scintigraphy is a marker of acute cholecystitis, possibly complicated by perforation or gangrene. A case of increased fluorodeoxyglucose uptake within the gallbladder fossa secondary to locally invasive gallbladder carcinoma reminiscent of a classic rim sign is presented.

Management of gallbladder cancer

Resection is a means of improving survival in patients with gallbladder cancer. A more aggressive surgical approach, including resection of the gallbladder, liver, and regional lymph nodes, is advisable for patients with T1b to T4 tumors. Aggressive resection is necessary because a patient's gallbladder cancer stage determines the outcome, not the surgery itself. Therefore, major resections should be offered to appropriately selected patients. Patients with advanced tumors or metastatic disease are not candidates for radical resection and thus should be directed to more suitable palliation.

Xanthogranulomatous cholecystitis mimicking gallbladder carcinoma with a false-positive result on fluorodeoxyglucose PET

Recently, several reports have demonstrated that fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) is useful in differentiating between benign and malignant lesions in the gallbladder. However, there is a limitation in the ability of FDG-PET to differentiate between inflammatory and malignant lesions. We herein present a case of xanthogranulomatous cholecystitis misdiagnosed as gallbladder carcinoma by ultrasonography and computed tomography. FDG-PET also showed increased activity. In this case, FDG-PET findings resulted in a false-positive for the diagnosis of gallbladder carcinoma.

Does PET-CT scan have a role prior to radical re-resection for incidental gallbladder cancer?

BACKGROUND

Radical re-resection is offered to patients with non-metastatic, invasive, incidental gallbladder cancer. Data evaluating (18)F-fluorodeoxyglucose positron emission tomography-computed tomography ((18)F-FDG PET-CT) in patients with incidental gallbladder cancer is sparse.

AIM

To evaluate the efficacy of integrated (18)F-FDG PET-CT in determining occult metastatic or residual local-regional disease in patients with incidental gallbladder cancer.

METHODS

Patients referred with incidental gallbladder cancer for radical re-resection were evaluated using multidetector computed tomography (MDCT) and PET-CT. Based on preoperative imaging, 24 out of 92 patients were found suitable for surgery. The two imaging modalities were evaluated with respect to residual and resectable disease.

RESULTS

In determining residual disease, MDCT had a sensitivity and positive predictive value (PPV) of 42.8%, each, while PET-CT had a sensitivity and PPV of 28.5 and 20%, respectively. In determining resectability, MDCT had a sensitivity, PPV, and accuracy of 100, 87.5, and 87.5%, respectively, as compared to PET-CT (sensitivity=100%, PPV=91.3%, accuracy=91.6%).

CONCLUSIONS

From our study, it appears that in patients with incidental gall bladder cancer without metastatic disease, PET-CT and MDCT seem to have roles complementing each other. PET-CT was able to detect occult metastatic or residual local-regional disease in some of these patients, and seems to be useful in the preoperative diagnostic algorithm of patients whose MDCT is normal or indicates locally advanced disease.

Port site and distant metastases of gallbladder cancer after laparoscopic cholecystectomy diagnosed by positron emission tomography

We report port site and distant metastases of unsuspected gallbladder cancer after laparoscopic cholecystectomy diagnosed by positron emission tomography (PET) in two patients. Patient 1, a 72-year-old woman was diagnosed as cholelithiasis and cholecystitis and received laparoscopic cholecystectomy. Unsuspected gallbladder cancer was discovered with histological result of well-differentiated squamous cell carcinoma of the gallbladder infiltrating the entire wall. A PET scan using F-18-fluorodeoxyglucose (FDG-PET) before radical resection revealed residual tumor in the gallbladder fossa and recurrence at port site and metastases in bilateral hilar lymph nodes. Patient 2, a 69-year-old woman underwent laparoscopic cholecystectomy more than one year ago with pathologically confirmed unsuspected adenosquamous carcinoma of stage pT1b. At 7-mo follow-up after surgery, the patient presented with nodules in the periumbilical incision. Excisional biopsy of the nodule revealed adenosquamous carcinoma. The patient was examined by FDG-PET, demonstrating increased FDG uptake in the right lobe of the liver and mediastinal lymph nodes consistent with metastatic disease. This report is followed by a discussion about the utility of FDG-PET in the gallbladder cancer.

Gallbladder carcinoma

Although it is the most common cancer of the biliary tree, gallbladder carcinoma remains an uncommon disease. As a result, many clinicians rarely encounter it and there is uncertainty regarding proper management. Resection is the most effective and only potentially curative treatment. Early stage tumors are often curable with a proper resection; however, many patients present late in the course of the disease when surgical intervention is no longer effective. While other treatment modalities are used in patients with advanced disease, there is limited data on efficacy. In many cases, the diagnosis is made after a cholecystectomy has been performed and an incidental tumor is identified in the specimen. In such cases, reoperation and definitive resection is appropriate and effective for patients with invasive lesions.