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

Open versus laparoscopic radical cholecystectomy for incidental and non-incidental gallbladder cancer. A propensity score analysis in a retrospective cohort from Chilean center

BACKGROUNDS

Radical cholecystectomy (RC) has few comparative studies between open (ORC) and laparoscopic (LRC) techniques for the treatment of gallbladder cancer (GBC). Our aim is to evaluate the short- and long-term outcomes of ORC versus LRC for the treatment of GBC in a high incidence center.

METHODS

Retrospective cohort study. All patients with incidental and non-incidental CVB from June 2014 to December 2021 in Regional Hospital of Talca, Chile were included. A comparison between ORC and LRC was performed for perioperative surgical and oncologic variables. Survival analysis was performed using the Kaplan-Meier method and Cox Regression.

RESULTS

A total of 312 patients were evaluated, 250 (80.4 %) were excluded due to stage IV at diagnosis and/or non-curative treatment. 62 (19.9 %) were treated with RC, 34(55 %) of them by laparoscopy. 51(82.6 %) were women. Mean age 62.7 years. 43 (68.8 %) were incidental GBC. 46 (75.8 %) were T2-3 GBC. Surgical time, resected lymph nodes, weight of the operative specimen, tumor type and R0 resection were not different between ORC and LRC. Hemorrhage, morbidity and operative stay were lower with LRC(p < 0.05). 1 (1.7 %) patient died after ORC (p = NS). With a median follow-up of 30 months the median survival at 12, 36 and 60 months was 92 %, 74 % and 72 % respectively. A multivariate survival analysis showed that TNM stage was the only factor associated with survival.

CONCLUSION

The short- and long-term results of LRC were better than ORC. A PSM analysis showed no significant difference; therefore, LRC should be adopted as the technique of choice when technically feasible.

Update on the Role of Imaging in the Diagnosis, Staging, and Prognostication of Gallbladder Cancer

Gallbladder cancer (GBC) is a highly aggressive malignancy with dismal prognosis. GBC is characterized by marked geographic predilection. GBC has distinct morphological types that pose unique challenges in diagnosis and differentiation from benign lesions. There are no specific clinical or serological markers of GBC. Imaging plays a key role not only in diagnosis and staging but also in prognostication. Ultrasound (US) is the initial test of choice that allows risk stratification in wall thickening and polypoidal type of gallbladder lesions. US findings guide further investigations and management. Computed tomography (CT) is the test of choice for staging GBC as it allows comprehensive evaluation of the gallbladder lesion, liver involvement, lymph nodes, peritoneum, and other distant sites for potential metastases. Magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography allow better delineation of the biliary system involvement. Contrast-enhanced US and advanced MRI techniques including diffusion-weighted imaging and dynamic contrast-enhanced MRI are used as problem-solving tools in cases where distinction from benign lesion is challenging at US and CT. Positron emission tomography is also used in selected cases for accurate staging of the disease. In this review, we provide an up-to-date insight into the role of imaging in diagnosis, staging, and prognostication of GBC.

Multiparameter diagnostic model based on 18F-FDG PET metabolic parameters and clinical variables can differentiate nonmetastatic gallbladder cancer and cholecystitis

OBJECTIVE

To evaluate the diagnostic value of a multiparameter model based on ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) metabolic parameters and clinical variables in differentiating nonmetastatic gallbladder cancer (GBC) from cholecystitis.

PATIENTS AND METHODS

In total, 122 patients (88 GBC nonmetastatic patients and 34 cholecystitis patients) with gallbladder space-occupying lesions who underwent ¹⁸F-FDG PET/CT were included. All patients received surgery and pathology, and baseline characteristics and clinical data were also collected. The metabolic parameters of ¹⁸F-FDG PET, including SUVmax (maximum standard uptake value), SUVmean (mean standard uptake value), SUVpeak (peak standard uptake value), MTV (metabolic tumour volume), TLG (total lesion glycolysis) and SUVR (tumour-to-normal liver standard uptake value ratio), were evaluated. The differential diagnostic efficacy of each independent parameter and multiparameter combination model was evaluated using the receiver operating characteristic (ROC) curve. The improvement in diagnostic efficacy using a combination of the above multiple parameters was evaluated by integrated discriminatory improvement (IDI), net reclassification improvement (NRI) and bootstrap test. Decision curve analysis (DCA) was used to evaluate clinical efficacy.

RESULTS

The ROC curve showed that SUVR had the highest diagnostic ability among the ¹⁸F-FDG PET metabolic parameters (area under the curve [AUC] = 0.698; sensitivity = 0.341; specificity = 0.971; positive predictive value [PPV] = 0.968; negative predictive value [NPV] = 0.363). The combined diagnostic model of cholecystolithiasis, fever, CEA > 5 ng/ml and SUVR showed an AUC of 0.899 (sensitivity = 0.909, specificity = 0.735, PPV = 0.899, NPV = 0.758). The diagnostic efficiency of the model was improved significantly compared with SUVR. The clinical efficacy of the model was confirmed by DCA.

CONCLUSIONS

The multiparameter diagnostic model composed of ¹⁸F-FDG PET metabolic parameters (SUVR) and clinical variables, including patient signs (fever), medical history (cholecystolithiasis) and laboratory examination (CEA > 5 ng/ml), has good diagnostic efficacy in the differential diagnosis of nonmetastatic GBC and cholecystitis.

Gallbladder polyps and adenomyomatosis

Incidental findings are commonly detected during examination of the gallbladder. Differentiating benign from malignant lesions is critical because of the poor prognosis associated with gallbladder malignancy. Therefore, it is important that radiologists and sonographers are aware of common incidental gallbladder findings, which undoubtedly will continue to increase with growing medical imaging use. Ultrasound is the primary imaging modality used to examine the gallbladder and biliary tree, but contrast-enhanced ultrasound and MRI are increasingly used. This review article focuses on two common incidental findings in the gallbladder; adenomyomatosis and gallbladder polyps. The imaging features of these conditions will be reviewed and compared between radiological modalities, and the pathology, epidemiology, natural history, and management will be discussed.

Combining polyp diameter and polyp-to-bile ratio by dynamic contrast-enhanced CT scanning can improve the diagnostic specificity of gallbladder neoplastic polyps

OBJECTIVE

This study aimed to distinguish between cholesterol and neoplastic gallbladder polyps using dynamic contrast-enhanced CT.

METHODS

The dataset retrospectively comprised 222 cases, including 106 cases of cholesterol polyps and 116 cases of neoplastic polyps (59 adenoma and 57 adenocarcinoma). The perception and Hounsfield units of the polyps and gallbladder bile were assessed by contrast-enhanced CT, and the polyp-to-bile ratio (PBR) was calculated. Receiver operating characteristic (ROC) curves and area under the curve analyses were used to assess the diagnostic value of the diameter and PBR for neoplastic polyps.

RESULTS

The diameter of cholesterol polyps was significantly smaller than that of neoplastic polyps. The proportion of perceived cholesterol polyps in the plain and arterial phases of CT were significantly lower than those of neoplastic polyps (p < .001). On the contrary, the CT values of gallbladder bile of cholesterol polyps were always significantly higher than those of neoplastic polyps (p < .001). The median PBR values of cholesterol polyps were significantly lower than those of neoplastic polyps (p ≤ .001). ROC analysis showed that diameter and a plain phase PRB had better diagnostic value for neoplastic polyps. Polyp diameter ≥ 11.95 mm and the plain phase PBR ≥1.48 were the optimal cut-off values for diagnosis of neoplastic polyps. Combining a diameter ≥ 12 mm and a PBR in the plain phase ≥1.48 further improved neoplastic polyp diagnostic specificity and positive likelihood ratio (10.453).

CONCLUSIONS

Polyp-to-bile ratio in contrast-enhanced CT scanning is a new and convenient index for identifying cholesterol and neoplastic gallbladder polyps.

Asymptomatic chronic suppurative cholecystitis and peritonitis mimicking metastasis by 18F-FDG PET/CT scan during sigmoid colon cancer surveillance

The study describes an unusual case that a patient with previous history of adenocarcinoma of sigmoid colon who has developed chronic suppurative cholecystitis and peritonitis was misdiagnosed as metastasis. This case is presented to illustrate the importance of considering benign etiologies that may mimic metastatic disease when interpreting positron emmision tomography (PET)/CT scans.

Clinical and metabolic parameters for predicting disease progression of gallbladder adenocarcinoma

OBJECTIVE

This study aimed to identify reliable predictors of disease progression in patients with gallbladder (GB) adenocarcinoma.

PATIENTS AND METHODS

A total of 54 patients with GB adenocarcinoma underwent preoperative F-18 fluorodeoxyglucose (FDG) PET/CT. Age, sex, clinical stage, and pathologic differentiation were collected. Tumor size and PET parameters such as SUVmax, SUVmean, SUVpeak, metabolic tumor volume (MTV), and total lesion glycolysis were measured. Univariate and multivariate logistic regression analyses were performed to determine the utility of clinical values and PET parameters. Pearson bivariate correlation was used to evaluate the association between progression-free survival (PFS) and various parameters.

RESULTS

No recurrence was found in 15 of 54 patients, while six showed recurrence and another 33 manifested disease progression. There were significant differences in size, stage, pathologic differentiation, and PET parameters between the groups with and without recurrence/progression. However, there was no difference in those parameters between the groups with recurrence and progression. The average PFS of the groups with no recurrence, recurrence, and progression groups was 33.1, 17.1, and 5.0 months, respectively. In univariate analysis, age, sex, clinical stage, pathologic differentiation, size, and PET parameters were correlated with PFS. In multivariate analysis, only clinical stage and MTV were statistically significant and MTV showed the highest odds ratio. Pearson correlation coefficients showed moderate negative correlations between PFS and clinical stage or MTV.

CONCLUSION

In GB adenocarcinoma, clinical stage and MTV are the most powerful parameters for predicting recurrence and disease progression. Based on clinical stage, MTV will represent a strong prognostic predictor.

Carcinosarcoma of gallbladder: A world review

BACKGROUND

Gallbladder carcinosarcoma is a rare hepatobiliary tumor comprising of both carcinomatous and sarcomatous components. Due to its rarity, the literature with regards to the topic is scarce and currently lacking, spanning less than 100 cases.

AIM

To summarize the current literature on gallbladder carcinosarcoma.

METHODS

A literature review was performed on the PubMed database using the keywords "Gallbladder" AND "Carcinosarcoma" from 1970 to 2021. Additionally, similar searches were performed on MEDLINE and Web of Science.

RESULTS

Risk factors noted include female gender, gallstones and chronic cholecystitis. In the absence of any diagnostic biochemical testing or tumor markers, imaging modality serves as the key initial impression tool, which can be histologically confirmed only post-resection. While surgery is the only curative option, the use of adjunctive chemotherapy has been considered on top of excision in recent years, with some success.

CONCLUSION

While this study has taken steps to bridge the gap in the literature, more cases should be reported to further ascertain the current associations and management potential for gallbladder carcinosarcoma.

Management and follow-up of gallbladder polyps: updated joint guidelines between the ESGAR, EAES, EFISDS and ESGE

Abstract

Main recommendations

Primary investigation of polypoid lesions of the gallbladder should be with abdominal ultrasound. Routine use of other imaging modalities is not recommended presently, but further research is needed. In centres with appropriate expertise and resources, alternative imaging modalities (such as contrast-enhanced and endoscopic ultrasound) may be useful to aid decision-making in difficult cases. Strong recommendation, low–moderate quality evidence.

Cholecystectomy is recommended in patients with polypoid lesions of the gallbladder measuring 10 mm or more, providing the patient is fit for, and accepts, surgery. Multidisciplinary discussion may be employed to assess perceived individual risk of malignancy. Strong recommendation, low-quality evidence.

Cholecystectomy is suggested for patients with a polypoid lesion and symptoms potentially attributable to the gallbladder if no alternative cause for the patient’s symptoms is demonstrated and the patient is fit for, and accepts, surgery. The patient should be counselled regarding the benefit of cholecystectomy versus the risk of persistent symptoms. Strong recommendation, low-quality evidence.

If the patient has a 6–9 mm polypoid lesion of the gallbladder and one or more risk factors for malignancy, cholecystectomy is recommended if the patient is fit for, and accepts, surgery. These risk factors are as follows: age more than 60 years, history of primary sclerosing cholangitis (PSC), Asian ethnicity, sessile polypoid lesion (including focal gallbladder wall thickening > 4 mm). Strong recommendation, low–moderate quality evidence.

If the patient has either no risk factors for malignancy and a gallbladder polypoid lesion of 6–9 mm, or risk factors for malignancy and a gallbladder polypoid lesion 5 mm or less, follow-up ultrasound of the gallbladder is recommended at 6 months, 1 year and 2 years. Follow-up should be discontinued after 2 years in the absence of growth. Moderate strength recommendation, moderate-quality evidence.

If the patient has no risk factors for malignancy, and a gallbladder polypoid lesion of 5 mm or less, follow-up is not required. Strong recommendation, moderate-quality evidence.

If during follow-up the gallbladder polypoid lesion grows to 10 mm, then cholecystectomy is advised. If the polypoid lesion grows by 2 mm or more within the 2-year follow-up period, then the current size of the polypoid lesion should be considered along with patient risk factors. Multidisciplinary discussion may be employed to decide whether continuation of monitoring, or cholecystectomy, is necessary. Moderate strength recommendation, moderate-quality evidence.

If during follow-up the gallbladder polypoid lesion disappears, then monitoring can be discontinued. Strong recommendation, moderate-quality evidence.

Source and scope

These guidelines are an update of the 2017 recommendations developed between the European Society of Gastrointestinal and Abdominal Radiology (ESGAR), European Association for Endoscopic Surgery and other Interventional Techniques (EAES), International Society of Digestive Surgery–European Federation (EFISDS) and European Society of Gastrointestinal Endoscopy (ESGE). A targeted literature search was performed to discover recent evidence concerning the management and follow-up of gallbladder polyps. The changes within these updated guidelines were formulated after consideration of the latest evidence by a group of international experts. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was adopted to define the strength of recommendations and the quality of evidence.

Key Point

• These recommendations update the 2017 European guidelines regarding the management and follow-up of gallbladder polyps.

Impact of fluorine-18-fluorodeoxyglucose PET/computed tomography in staging of patients with gallbladder cancer: a systematic review and meta-analysis

BACKGROUND

Fluorine-18-fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) has proven its efficacy in various malignancies; however, currently it is not used routinely for the management of gallbladder carcinoma (GBCa). So, we tried to review and analyze the impact of FDG PET/CT in the staging workup of gallbladder carcinoma.

METHODS

Databases like PubMed, SCOPUS, and EMBASE were searched for published original studies on F-18 FDG PET/CT in staging workup gallbladder carcinoma till December 2020. The included studies were assessed using the Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) checklist. A random-effect model was used for calculating pooled estimates of sensitivity and specificity. They were demonstrated in Forest plots. I2 statistic was used to assess heterogeneity in the studies.

RESULTS

There is a paucity of literature with respect to the role of FDG PET/CT in GBCa. With the available data, the pooled sensitivity and specificity of 18F-FDG PET/CT for detection of local disease estimates of 96% [95% confidence interval (CI), 90-99%] and 91% (95% CI, 77-98%), respectively. Pooled sensitivity and specificity for detection of metastatic disease are 95% (95% CI, 88-98%) and 97% (95% CI, 90-100%), respectively. For nodal disease, these values are 75% (95% CI, 53-90%) and 91% (95% CI, 77-98%), respectively. Besides this, FDG PET/CT findings have changed the management in significant proportion of patients.

CONCLUSION

With the limited data available currently, we found that 18F-FDG PET/CT is a quite accurate noninvasive tool in staging the workup of GBCa. However, further large multicentre trials are necessary for the generation of stronger evidence in this regard.

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.

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.

The Role of Positron Emission Tomography in Pancreatic Cancer and Gallbladder Cancer

18F-FDG-PET is complementary to conventional imaging in patients with clinical suspicion for exocrine pancreatic malignancies. It has similar if not superior sensitivity and specificity for detection of cancer, and when combined with contrast enhanced anatomic imaging of the abdomen, can improve diagnostic accuracy and aid in staging, assessment for resectability, radiation therapy planning, and prognostication. Various metabolic pathways affect FDG uptake in pancreatic ductal adenocarcinoma. The degree of uptake reflects histopathology, aggressiveness, metastatic potential, and metabolic profile of malignant cell and their interaction with cancer stroma. After treatment, FDG-PET is useful for detection of residual or recurrent cancer and can be used to assess and monitor response to therapy in unresectable or metastatic disease. The degree and pattern of uptake combined with other imaging features are useful in characterization of incidental pancreatic lesions and benign processes such as inflammation. Several novel PET radiopharmaceuticals have been developed to improve detection and management of pancreatic cancer. Gallbladder carcinoma is typically FDG avid and when anatomic imaging is equivocal PET can be used to assess metastatic involvement with high specificity and inform subsequent management.

Evaluation of gallbladder wall thickening: a multimodality imaging approach

INTRODUCTION

Gallbladder (GB) wall thickening is a relatively common finding on imaging. While there are clear recommendations for the management of gallstones, GB wall thickening presents a significant challenge. Despite advances in radiological as well as endoscopic techniques, the ability to characterize GB wall thickening is still limited.

AREAS COVERED

This review summarizes the currently available literature on various imaging investigations to characterize GB wall thickening. This review also summarizes the differences between benign and malignant GB wall thickening based on available imaging modalities. Transabdominal ultrasonography is the first-line investigation for evaluation of GB wall thickening. However, further characterization requires additional imaging tests. Magnetic resonance imaging (MRI) with the use of gadolinium and diffusion-weighted sequence is the preferred modality for GB wall characterization.

EXPERT OPINION

The accurate characterization of GB wall thickening is a challenging task. The available imaging criteria allow differentiation of benign and malignant GB wall thickening with moderate accuracy. The advanced imaging techniques, including contrast enhanced ultrasound, contrast-enhanced endoscopic ultrasound, and shear wave elastography, continue to evolve. There is a need for a well-designed reporting system for GB wall thickening to ensure uniformity of reporting of imaging tests, especially in regions with a high prevalence of GB cancer.