Role of 18F-FDG PET/CT in detecting recurrent gallbladder carcinoma. Clin Nucl Med. 2012;37:431-435. [PMID: 22475890 DOI: 10.1097/rlu.0b013e31824d24c4]

Gallbladder cancer: Progress in the Indian subcontinent

Gallbladder cancer (GBC) is one of the commonest biliary malignancies seen in India, Argentina, and Japan. The disease has dismal outcome as it is detected quite late due to nonspecific symptoms and signs. Early detection is the only way to improve the outcome. There have been several advances in basic as well as clinical research in the hepatobiliary and pancreatic diseases in the West and other developed countries but not enough has been done in GBC. Therefore, it is important and the responsibility of the countries with high burden of GBC to find solutions to the many unanswered questions like etiopathogenesis, early diagnosis, treatment, and prognostication. As India being one of the largest hubs for GBC in the world, it is important to know how the country has progressed on GBC. In this review, we will discuss the outcome of the publications from India highlighting the work and the developments taken place in past several decades both in basic and clinical research.

Integrated FDG-PET/CT contribution over cross-sectional imaging in recurrence or progression of pancreaticobiliary neoplasms

PURPOSE

We aim to compare FDG-PET/CT and cross-sectional imaging (contrastenhanced CT/MRI) diagnostic abilities in detecting recurrence/progression of pancreaticobiliary system tumors and to reveal the clinical impact of integrated FDGPET/CT to CT/MRI on patient management.

MATERIALS AND METHODS

FDG-PET/CT and CT/MRI scans of 70 patients from initiation of treatment until proven recurrence/progression were retrospectively evaluated. FDGPET/CT and contrast-enhanced CT/MRI accuracy, sensitivity, specificity, PPV and NPV are compared in terms of overall recurrence/progression diagnosis and sitespecific concern; local disease, local lymph node, and distant organ metastasis. The impact of integrated FDG-PET/CT on patient management is scrutinized.

RESULTS

CT/MRI has higher sensitivity than FDG-PET/CT in detecting loco-regional involvement (90% vs 76.7% P: 0.152), local lymph node metastasis (88.9% vs 77.8%, P: 0.380) and distant organ metastasis (96.5% vs 80.7%; P: 0.006) in tumor recurrence/progression. In overall diagnosis, CT/MRI is more sensitive and accurate but less specific than FDG-PET/CT (92.3% vs 87.7%; 87.1% vs 84.2%; 40% vs 20%, respectively). In 8% (6/70) of patients FDG-PET/CT had a major impact on patient management.

CONCLUSION

FDG-PET/CT and cross-sectional imaging have different advantages and shortcomings. In recurrence/progression, recognition of early changes is more feasible by CT/MRI. However, inconsistency of morphologic and metabolic findings is important reason of cross-sectional imaging failure. FDG-PET/CT is superior in showing extraabdominal metastases, but missing small-volume lesions and misinterpreting inflammatory changes are still a problem lowering its sensitivity. Nevertheless FDGPET/CT is good option for guiding undetermined imaging findings or clinic-radiologic mismatch.

Utility of 18-Flurodeoxyglucose Positron Emission Tomography-Computed Tomography ( 18 FDG PET-CT) in Gallbladder Cancer: Experience from a Tertiary Care Hospital

Introduction  Gallbladder cancer (GBC) is one of the most common and aggressive malignancies of the Indo-Gangetic plains. Despite its widespread use in GBC cases, the role of 18-flurodeoxyglucose positron emission tomography-computed tomography ( 18 FDG PET-CT) in the management of this disease is not well defined. In our study, we present the practice trends of the utilization of this investigative modality in our hospital and its benefits in aiding diagnosis, staging, and surveillance for recurrence. Materials and Methods  All cases of suspected and biopsy-proven GBCs who underwent PET-CT at our institute between 2016 and 2019 were retrospectively evaluated for the indication of PET-CT testing and its impact on the management of the case. The indications were classified into three categories: (i) staging and metastatic workup, (ii) response assessment post-chemotherapy, and (iii) post-therapy surveillance of patients. Results  A total of 79 PET-CT scans were carried out during the study period. PET-CT was used for less than one-third of the total patients of GBC presenting at our center. Initial staging and workup (49%) was the most common indication followed by surveillance (28%) and response assessment (23%). PET-CT had a substantially better sensitivity in detecting distant metastases compared to conventional imaging in both initial workup and during follow-up. PET-CT provided additional information in 42% scans that led to change in the management of the patient. As a response assessment tool PET-CT aided not only in evaluating efficacy of therapy but also for documenting progressive disease for patients on therapy. Conclusion  PET-CT is a valuable tool to not only rule out metastatic disease while selecting patients for surgery but also for post-therapy surveillance for recurrence in patients of GBC. Larger prospective studies may help in finally elucidating the exact role of PET-CT in this disease.

Diagnostic performance of F-18 FDG PET/CT in recurrent adenocarcinoma gallbladder and its impact on post-recurrence survival

PURPOSE

To analyze diagnostic performance of F-18 FDG PET/CT in recurrent adenocarcinoma gallbladder (GBC) and to establish its possible impact on post-recurrence survival.

METHOD

FDG PET/CT studies of suspected recurrent GBC were retrospectively analyzed alongside tumor markers serum CEA and CA 19-9. Abnormal FDG-avid lesions and abnormal morphological lesions were considered positive for recurrence, and were categorized as isolated abdominal wall recurrence, loco-regional recurrence, and distant metastatic disease. Histopathology, definite progression on imaging and positive response to treatment was considered as reference standard. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were used as diagnostic performance parameters. Post-recurrence survival was calculated whenever appropriate follow-up was available, based on the abovementioned categories of sites of recurrence using survival curves and log-rank test.

RESULTS

Out of 117 PET/CT studies, 93 (79.5%) were positive and 24 (20.5%) were negative for recurrence. 86 out of 93 were true positive and 23 of 24 were true negative. PET/CT demonstrated sensitivity, specificity, PPV, NPV and accuracy of 98.8%, 76.7%, 92.5%, 95.8% and 93.1%, respectively. Diagnostic performance of PET/CT was significantly better than combination tumor markers. Of 66 cases with available follow-up, isolated abdominal wall (port/scar site) recurrence and loco-regional recurrence demonstrated significantly higher post-recurrence survival as compared to distant metastasis; median survival being 39, 25 and 12 months, respectively.

CONCLUSION

F-18 FDG PET/CT has better diagnostic performance than tumor markers combination. Isolated abdominal wall (port/scar site) recurrence and loco-regional recurrence on PET/CT demonstrated better survival than non-regional metastatic disease. These results suggest a possible role of PET/CT as a surveillance modality, as well as a guide to therapeutic decision-making in cases of recurrent GBC.

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.

The Role of Fine Needle Aspiration Cytology in the Diagnosis of Gallbladder Cancer: A Systematic Review

Gallbladder cancer is the most common malignancy of the biliary tract. When diagnosed in an advanced stage it has a very poor prognosis. Therefore, early diagnosis and thorough assessment of a suspicious gallbladder polyp is essential to improve survival rate. The aim of this systematic review is to assess the role of fine needle aspiration cytology (FNAC) in the management of gallbladder cancer. For that purpose, a systematic review was carried out in the MEDLINE, EMBASE, Cochrane, Scopus and Google Scholar databases between 1 July 2004 and 22 April 2021. Six studies with 283 patients in total were included. Pooled sensitivity and specificity of FNAC were 0.85 and 0.94, respectively, while the area under the calculated summary receiver operating characteristic (SROC curve (AUC) was 0.98. No complications were reported. Based on the high diagnostic performance of FNAC in the assessment of gallbladder masses, we suggest that every suspicious mass should be evaluated further with FNAC to facilitate the most appropriate management.

Locally advanced gallbladder cancer: a review of the criteria and role of imaging

Gallbladder carcinoma (GBC) is among one of the gastrointestinal malignancies with extremely dismal prognosis. This is due to the advanced stage at presentation. Majority of the patients with GBC are not considered candidates for surgery because of the locally advanced disease or metastases. However, with the accumulating evidence regarding the role of neoadjuvant chemotherapy, there is a need to correctly identify a subset of patients with locally advanced GBC who will benefit maximally from neoadjuvant chemotherapy and will be successfully downstaged to receive curative (R0) surgery. In this context, there is a lack of consensus and different groups have resorted to criteria for locally advanced disease eligible for neoadjuvant chemotherapy based on personal or institutional experiences. Imaging plays a critical role in the evaluation of patients with GBC as it helps stratify patients into resectable and unresectable. Imaging also has the potential to identify patients with locally advanced GBC and hence facilitate neoadjuvant chemotherapy and improve outcomes. In this review, we evaluate the various criteria for locally advanced GBC and the role of imaging in this scenario.

Gallbladder Carcinoma Presenting With Elbow Swelling

Common presentation of primary gallbladder carcinoma is with abdominal pain, or it may be detected incidentally in postcholecystectomy specimen for cholelithiasis. Primary gallbladder carcinoma spreads to adjacent hepatic parenchyma and locoregional nodes. Lung is a common extra-abdominal site, with other sites being relatively rare. We report a case of primary gallbladder carcinoma, which presented with elbow swelling in the absence of locoregional nodal spread detected on whole-body F-FDG PET/contrast-enhanced CT at initial evaluation.

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.

Role of positron emission tomography-contrast enhanced computed tomography in locally advanced gallbladder cancer

INTRODUCTION

This study aims to define the role of flurodeoxyglucose (^18F -FDG) positron emission tomography-contrast enhanced computed tomography (PETCECT) scan in upstaging disease in patients with locally advanced gallbladder cancer (LAGBC).

METHODS

An analysis of a prospectively maintained database of gallbladder cancer (GBC) patients was performed. Patients found to have locally advanced (T3 and/or T4 or N+) but non-metastatic disease on initial imaging, either a contrast enhanced computed tomography (CECT) or a magnetic resonance imaging (MRI) scan, underwent an additional PETCECT for staging and the results impacting treatment decision were recorded.

RESULTS

One hundred and three patients of LAGBC underwent CECT/MRI and PETCECT. 48/103 (46.6%) were found to be upstaged to stage IV after PETCECT. The most common metastatic site was non-regional retroperitoneal lymph nodes (12 patients, 11.7%) followed by satellite lesions in liver (11, 10.7%). Fourteen (13.6%) patients had equivocal findings on PET scan that required confirmation by tissue sampling out of which 10 (71.4%) were subsequently found to have metastatic disease. The only statistically significant factor predicting distant spread on PETCECT was the presence of loco-regional nodes on CT scan (odds ratio 6.15, P = .006).

CONCLUSION

PETCECT is a valuable tool to rule out metastatic disease in patients presenting with LAGBC.

The Role of 18F-FDG PET/CT in staging of gallbladder carcinomas

BACKGROUND/AIMS

Gallbladder Carcinoma (GBC) is the most common and aggressive tumor of the biliary tract. Patients are typically diagnosed during advanced stages, and the mean overall survival is short. In our study, we aimed to demonstrate the uptake patterns of 18F-FDG PET/CT in GBC, as well as its association with survival and diagnostic value during the initial stage.

MATERIALS AND METHODS

Overall, 17 patients with GBC were retrospectively included in the study. 18F-FDG PET/CT study was performed for pretreatment staging. Two different standardized uptake values (SUVmax and SUVmean), metabolic tumor volume 40% (MTV40), and tumor lesion glycolysis (TLG) of the primary tumors were compared between the clinical and histopathological groups.

RESULTS

Of the 17 patients, 11 were women (64.7%), and 6 (35.3%) were men. The mean age of the patients was 69.7±8.8 years. 18F-FDG uptake was detected in all lesions. Mean SUVmax was calculated to be 15.4±13.7 (median=10.6, range=3.4-46.8). All distant metastases (52.9%) were detected in the liver. Semiquantitative metabolic parameters (SUVmax and SUVmean, MTV40, and TLG) obtained from patients with distant metastasis were not significantly higher than those without distant metastasis. Similar results were obtained in patients with and without nodal metastasis. No statistically significant intergroup difference was observed regarding metabolic parameters. However, a statistically significant negative correlation was observed between the patient's age and the SUVmax of the primary lesion and metastatic lymph nodes (r=-0.564, p=0.018). During 10.7±10.4 months of mean follow-up, the mean survival of patients with distant metastases (6.1±11.0 months) was significantly shorter than that of patients with no organ metastases (15.8±7.1 months).

CONCLUSION

In our study, distant metastases and age were observed to be crucial prognostic factors in patients with gallbladder carcinoma (GBC). In addition, we believe that 18F-FDG PET/CT imaging will help to stage the GBC, detect nodal and distant metastasis, and evaluate the metabolic state of gallbladder lesions.

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.

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.

The surgical management of gallbladder cancer

Among biliary tract cancers, gallbladder cancer (GBC) is a potentially lethal malignancy with abysmal long-term survival. Surgery is central to the management of GBC, and presently, provides the only ray of hope for long-term survival. Radical cholecystectomy, which includes cholecystectomy with a limited hepatic resection, regional lymphadenectomy and adjacent organ resection if required is used to encompass the tumor with negative margins - R'0' resection is the standard surgical treatment for the management of GBC. Absence of randomized controlled trials to address various surgical controversies due to rarity of disease in western world, advanced disease at presentation, high frequency of unresectability/inoperability at surgery, deficient neoadjuvant/adjuvant strategies and nihilistic views of oncologists due to aggressive disease biology has resulted in marked heterogeneity in surgical strategies employed to manage GBC across the surgical centers globally.

Late Port Site Metastasis from Occult Gall Bladder Carcinoma After Laparoscopic Cholecystectomy for Cholelithiasis: The Role of (18)F-FDG PET/CT

Late port site metastasis of gall bladder carcinoma (GBC) after laparoscopic cholecystectomy is a rare finding. Rarer still is such a presentation where the GBC remained occult at histopathology. (18)F-flurodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) can play an important role in this setting by supporting the diagnosis of port site metastasis, by demonstrating additional sites of metastasis, if any, and by ruling out any other primary site. We here present two such patients with late port site metastasis of occult GBC after laparoscopic cholecystectomy for cholelithiasis and discuss the role of (18)F-FDG PET/CT in this setting.

Gallbladder carcinoma metastasizing to adrenal gland: a rare site demonstrated with (18)F-FDG PET/CT

Adrenal metastases have commonly been reported in a wide variety of cancers but not in gallbladder cancer. We here present a case of a 45-year-old male patient with gallbladder carcinoma where left adrenal metastasis was detected on staging F-FDG PET/CT. This was confirmed histopathologically. F-FDG PET/CT can have a significant impact on management of patients with gallbladder carcinoma by demonstrating rare sites of metastasis.

Solitary breast metastasis from recurrent gallbladder carcinoma simulating a second primary on 18F-FDG PET/CT

Gallbladder carcinoma is characterized by poor prognosis. It spreads by direct, lymphatic, vascular, neural, intraperitoneal, and intraductal routes. The most commonly involved organ is the liver followed by regional lymph nodes. Extra-abdominal metastases are comparatively rare. We present a case of solitary breast metastasis from recurrent gallbladder carcinoma mimicking a primary breast cancer in (18)F-FDG PET/CT.

Prognostic Value of SUVmax Measured by Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography with Computed Tomography in Patients with Gallbladder Cancer

OBJECTIVE

The aim of this study is to investigate the prognostic value of F-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography (PET)/computed tomography (CT) in gallbladder cancer patients.

METHODS

From June 2004 to June 2010, a total of 50 patients with gallbladder cancer who underwent diagnostic staging with F-18 FDG PET/CT following curative or palliative treatments were retrospectively evaluated. For the analysis, all patients were classified by age, sex, maximum standardized uptake value (SUVmax), lymph node (LN) or distant metastasis, serum level of CA19-9 and CEA, type of treatment and American Joint Committee on Cancer (AJCC) stage.

RESULTS

The median survival for the 50 patients was 245 days and the median SUVmax in PET/CT was 8.3 (range, 0-19.7). Patients with SUVmax < 6 survived significantly longer than patients with SUVmax ≥ 6 (median 405 days vs 203 days, p = 0.0400). On Kaplan-Meier analysis, SUVmax (p = 0.0400), stage (p = 0.0001), CA19-9 (p = 0.013), CEA (p = 0.006), LN metastasis (p = 0.0001), distant metastasis (p = 0.0020), type of treatment (p = 0.0001) were significantly associated with overall survival. Multivariate analysis study revealed that the patients with lower SUVmax measured from initial staging PET/CT (p = 0.0380), no LN metastasis (p = 0.0260), a lower stage (p = 0.026) and curative treatment (p = 0.0005) had longer survivals.

CONCLUSIONS

The present study shows that SUVmax on F-18 FDG PET/CT can provide prognostic information in patients with gallbladder cancer.

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.