18F-fluorodeoxyglucose positron emission tomography/computed tomography in AIDS-related Burkitt lymphoma

This study aims to describe 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) findings in patients with AIDS-related Burkitt lymphoma, at various times of treatment, and to define its utility for a better patient management. We retrospectively studied 13 consecutive HIV-positive patients with Burkitt lymphoma who underwent one or more PET/CT. In 5 of 5 patients imaged before treatment, PET/CT confirmed all involved sites detected at conventional work-up and demonstrated additional sites in 4 of 5 patients. Lymph node involvement, which is known to be uncommon in endemic or sporadic Burkitt lymphoma, was present in 54% of patients. Additionally, in 3 patients, Burkitt lymphoma was predominantly located in parotid lymph nodes, which is also an unusual finding. A negative scan was encountered in 3 of 10 patients imaged during treatment and in 1 of 4 patients imaged after treatment completion and was always associated with lasting complete remission. Presence of residual area of uptake was related to both favorable and unfavorable outcome whether performed during treatment (5/7 and 2/7, respectively) or after (1/3 and 2/3, respectively). Areas of increased uptake could be observed in lung (4 cases) or esophagus (3 cases), and were clinically related to pneumonia or esophagitis. We recommend PET/CT for accurate initial staging of patients with AIDS-related Burkitt lymphoma. PET/CT is also useful to monitor treatment response, as regression of initial disease can be early observed. Furthermore, PET/CT appears to have prognostic value, as a negative scan was always associated with a favorable outcome.     

Incidental focal colorectal 18F-fluorodeoxyglucose uptake on positron emission tomography/computed tomography

AIM: To assess the clinical significance of incidental focal colorectal 18 F-fluorodeoxyglucose ( 18 F-FDG) uptake on 18 F-FDG-positron emission tomography/computed tomography (PET/CT). METHODS: The records of all the cases which had undergone colonoscopy after PET/CT within a two weeks interval were reviewed. Adenomas were considered advanced when they were villous, ≥ 10 mm in size, or had high-grade dysplasia. Colorectal cancers and advanced adenomas are collectively referred to as advanced colorectal neoplasms. Receiver-operating characteristic curve analysis was used to determine thesignificant predictive maximum standardized uptake value (SUVmax) cutoff value for advanced colorectal neoplasms and cancer. RESULTS: Ninety-five colorectal lesions matched the site of incidental focal colorectal 18 F-FDG uptake on PET/CT and 146 did not. Colonoscopy showed advanced colorectal neoplasms corresponding to the site of 18 F-FDG uptake in 49 of the 95 (51.5%) lesions with incidental uptake. Of the lesions without incidental uptake, only 6 of 146 (4.1%) had advanced colorectal neoplasms on colonoscopy, indicating a statistically significant difference between the two groups (P < 0.001). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of incidental focal 18 F-FDG uptake in identifying advanced colorectal neoplasms were 89.1%, 75.3%, 51.6%, 95.9%, and 78.4%, respectively. In detecting only CRC, these values were 89.2%, 69.6%, 34.7%, 97.3%, and 72.6%, respectively. The significant SUVmax cutoff value for advanced colorectal neoplasms (area under the curve 0.755, P < 0.001) was 4.35, with a sensitivity, specificity, PPV, NPV, and accuracy of 75.5%, 65.2%, 69.8%, 71.4% and 70.5%, respectively. For CRC, 5.05 was the significant SUVmax cutoff value (area under the curve 0.817, P < 0.001), with a sensitivity, specificity, PPV, NPV, and accuracy of 84.8%, 71.0%, 80.9%, 89.8%, and 75.8%, respectively. CONCLUSION: The presence of incidental focal colorectal 1     

The role of 18fluoro-deoxyglucose positron emission tomography/computed tomography in resectable pancreatic cancer

BackgroundThe role of ¹⁸fluoro-deoxyglucose positron emission tomography/computed tomography in pancreatic ductal adenocarcinoma is debated. We retrospectively assessed the value of ¹⁸fluoro-deoxyglucose positron emission tomography/computed tomography in addition to conventional imaging as a staging modality in pancreatic cancer.Methods¹⁸Fluoro-deoxyglucose positron emission tomography/computed tomography was performed in 72 patients with resectable pancreatic carcinoma after multi-detector computed tomography positron emission tomography was considered positive for a maximum standardized uptake value >3.ResultsOverall, 21% of patients had a maximum standardized uptake value ≤3, and 60% of those had undergone neoadjuvant treatment (P = 0.0001). Furthermore, 11% of patients were spared unwarranted surgery since positron emission tomography/computed tomography detected metastatic disease. All liver metastases were subsequently identified with contrast-enhanced ultrasound. Sensitivity and specificity of positron emission tomography/computed tomography for distant metastases were 78% and 100%. The median CA19.9 concentration was 48.8 U/mL for the entire cohort and 292 U/mL for metastatic patients (P = 0.112).ConclusionsThe widespread application of ¹⁸fluoro-deoxyglucose positron emission tomography/computed tomography in patients with resectable pancreatic carcinoma seems not justified. It should be considered in selected patients at higher risk of metastatic disease (i.e. CA19.9 > 200 U/mL) after undergoing other imaging tests. Neoadjuvant treatment is significantly associated with low metabolic activity, limiting the value of positron emission tomography in this setting.     

推进18F-FDG PET/CT显像在心血管炎症的临床应用

炎症是多种心血管疾病的主要致病因素或重要病理特征,对其进行精准评价具有重要的临床意义。18氟标记脱氧葡萄糖正电子发射型计算机断层扫描显像(18F-FDG PET/CT)作为功能性影像技术,能特异地显示炎症活性。近年来的研究表明,18F-FDG PET/CT在动脉粥样硬化、感染性心内膜炎、心脏结节病、急性心肌梗死和血管炎等疾病的诊断、鉴别诊断、治疗决策制定和预后评估等方面具有独特的价值。随着PET/CT在我国的加快普及和推广,有望在心血管炎症疾病的诊疗中发挥更大的作用。     

~(18)F-Fluorodeoxyglucose positron emission tomography/computed tomography comparison of gastric lymphoma and gastric carcinoma

AIM To compare ~(18)F-fluorodeoxyglucose positron emission tomography/computed tomography(~(18)F-FDG PET/CT) features in gastric lymphoma and gastric carcinoma.METHODS Patients with newly diagnosed gastric lymphoma or gastric carcinoma who underwent ~(18)F-FDG PET/CT prior to treatment were included in this study. We reviewed and analyzed the PET/CT features of gastric wall lesions,including FDG avidity,pattern(focal/diffuse),and intensity [maximal standard uptake value:(SUVmax)]. The correlation of SUVmax with gastricclinicopathological variables was investigated by χ~2 test,and receiver-operating characteristic(ROC) curve analysis was performed to determine the differential diagnostic value of SUVmax-associated parameters in gastric lymphoma and gastric carcinoma. RESULTS Fifty-two patients with gastric lymphoma and 73 with gastric carcinoma were included in this study. Abnormal gastric FDG accumulation was found in 49 patients(94.23%) with gastric lymphoma and 65 patients(89.04%) with gastric carcinoma. Gastric lymphoma patients predominantly presented with type Ⅰ and type Ⅱ lesions,whereas gastric carcinoma patients mainly had type Ⅲ lesions. The SUVmax(13.39 ± 9.24 vs 8.35 ± 5.80,P 0.001) and SUVmax/THKmax(maximal thickness)(7.96 ± 4.02 vs 4.88 ± 3.32,P 0.001) were both higher in patients with gastric lymphoma compared with gastric carcinoma. ROC curve analysis suggested a better performance of SUVmax/THKmax in the evaluation of gastric lesions between gastric lymphoma and gastric carcinoma in comparison with that of SUVmax alone.CONCLUSION PET/CT features differ between gastric lymphoma and carcinoma,which can improve PET/CT evaluation of gastric wall lesions and help differentiate gastric lymphoma from gastric carcinoma.     

Diagnostic value of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in patients with fever of unknown origin

Background

While fever of unknown origin (FUO) remains a challenging problem in clinical practice, fluorine-18 fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) has been considered helpful in diagnosing its cause. The present study is set to evaluate the diagnostic value of PET/CT for patients with FUO.

Methods

We analyzed the records of 48 patients with FUO (34 men and 14 women; mean age of 57-year-old with a range between 24- and 82-year-old). The patients were examined by ¹⁸F-FDG PET/CT and the results were compared to a final diagnosis that was established by additional procedures.

Results

A final diagnosis was established for 36 patients (75%). Among them, 15 patients had infectious diseases, 12 patients had malignancies, and 9 patients had non-infectious inflammatory diseases. Thirty-two abnormal PET/CT results correctly revealed the source of fever (true-positives). Abnormal PET/CT results were considered false-positives for 8 patients without diagnoses. Normal PET/CT results in 4 patients with no diagnoses were classified as true-negatives. Four patients with normal PET/CT results with diagnosed cause for FUO were considered false-negatives. Therefore, PET/CT had a positive predictive value of 80%, a negative predictive value of 50%, a sensitivity of 89%, and a specificity of 33% in patients with FUO.

Conclusions

Our study demonstrated that FDG-PET/CT is a valuable imaging tool for the identification of the etiology in patients with FUO. The results suggest that this procedure may be considered as a second-line test, especially when conventional structural imaging was normal or unable to distinguish lesions from benign and malignant.     

Positron emission tomography and computed tomography versus positron emission tomography computed tomography: tools for imaging the lung

This article reviews the potential use of positron emission tomography (PET), alone and in combination with computed tomography, for evaluating the severity of disease in cystic fibrosis. PET scanning using injected 18F-fluorodeoxyglucose provides visual and quantitative information for the rate at which glucose is taken up by the lung, a process that should relate to the presence of inflammation and reflect the extent of the disease. The computed tomography scan gives highly accurate density and anatomic information to locate areas of inflammation seen on the PET scan, increasing the accuracy of the interpretation. Until recently, the scanners have been single systems, often located in separate hospital departments. Combined systems are now commercially available, with major advantages for patients and in the quality of analytical information obtained for interpretation by the physician. The use of 18F-fluorodeoxyglucose uptake and PET scanning has been suggested as a biomarker of progressive pulmonary inflammation in cystic fibrosis. Although promising, the data so far are limited. Further studies will be needed to validate this measurement for this purpose.     

Advantages and limitations of 18-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography in the diagnosis of infective endocarditis

IntroductionThe early diagnosis of infective endocarditis (IE) is a medical challenge and a multidisciplinary approach is essential to improve its frequently fatal prognosis. Our goal was to evaluate the usefulness of [¹⁸F]2-fluoro-2-deoxy-d-glucose positron emission tomography (¹⁸F-FDG PET) in the diagnosis of this disease.Materials and MethodsWe prospectively assessed 43 patients (five female and 38 male) with clinical suspicion of IE between 2014 and 2017. All patients underwent transesophageal echocardiography (TEE) and an ¹⁸F-FDG PET scan, and the results were compared. A positive PET finding was defined as increased FDG uptake on cardiac valves or intracardiac devices.ResultsOut of 43 patients with suspected IE, the diagnosis was confirmed in 30 cases (79.7%). ¹⁸F-FDG PET was positive in 24 patients, with 19 showing FDG uptake on cardiac valves (two native and 17 prosthetic) and five on cardiac devices, being concordant with echocardiographic findings in 11 cases. ¹⁸F-FDG PET sensitivity was 80%, specificity 92%, positive predictive value (PPV) 96% and negative predictive value (NPV) 66%. Echocardiography presented sensitivity, specificity, PPV and NPV of 36%, 84%, 84% and 36%, respectively.Conclusions¹⁸F-FDG PET proved to be a sensitive technique with a high diagnostic value in patients with prosthetic valves and intracardiac devices and suspected IE. Its utility decreased dramatically in patients with suspected IE on native valves, in which TEE presented higher sensitivity and thus better diagnostic value.     

Advantages of 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography in detecting post cardiac surgery infections

The 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) offers an excellent negative predictive value. Consequently, it is a reliable tool for excluding an infectious phenomenon in case of negativity. In case of persistent fever of unknown origin after cardiac surgery and in combination with other bacteriological examinations and medical imaging, we can rely on FDG-PET/CT to confirm or eliminate deep infections and prosthetic endocarditis. For this reason, FDG-PET/CT should be considered among the examinations to be performed in case of suspected infection after cardiac surgery. We have reported the case of a 76-year-old man who presented with a fever of unknown origin and recurrent septic shocks after a biological Bentall procedure combined with left anterior descending (LAD) coronary artery revascularization by the left internal thoracic artery. We performed a FDG-PET/CT which showed external iliac vein and right common femoral vein hyperfixation with infiltration of adjacent soft tissues, highly suspected to be an infectious process.

Learning objective

The aim of this case report is to show that FDG-PET/CT, in combination with other bacteriological examinations and medical imaging, can be extremely helpful in detecting deep infectious sources, even during the early postoperative period.     

Evaluation of recurrence in gastric carcinoma: Comparison of contrast-enhanced computed tomography and positron emission tomography/computed tomography

AIM To compare the value of contrast-enhanced abdominal computed tomography(CT) and fluorodeoxyglucose(FDG) positron emission tomography/computed tomography(PET/CT) for detecting gastric carcinoma recurrence.METHODS We retrospectively examined data from 2475 patients who underwent both contrast-enhanced abdominal CT and FDG PET/CT for the surveillance of gastric carcinoma curative resection. Patients had an interval of less than 1 mo between their CT and PET/CT scans. Sixty patients who had recurrence were enrolled. Among 1896 patients who did not have recurrence, 60 were selected by simple random sampling. All CT and PET/CT images were reviewed retrospectively by two reviewers blinded to all clinical and pathologic information except curative resection due to gastric carcinoma. RESULTS The pathological stage of the recurrence group was statistically significantly higher than that of the control group(P 0.001). In the 60 patients who had recurrence, there were 79 recurrent lesions. Fortyfour patients had only one location of recurrence, 13 patients had two locations, and 3 patients had three. In the detection of patient-based overall recurrence, no statistically significant differences existed between the two modalities(P = 0.096). However, for peritoneal carcinomatosis, CT had a statistically significantly higher sensitivity compared to PET/CT(96% vs 50%, P = 0.001). Adenocarcinoma was the most common type of gastric carcinoma. On the pathology-based analysis, CT also had a statistically significantly higher sensitivity compared to PET/CT(98% vs 80%, P = 0.035).CONCLUSION Contrast-enhanced CT was superior to PET/CT in the detection of peritoneal carcinomatosis and pathologic type of adenocarcinoma.     

18F-Fluorodeoxyglucose positron emission tomography in Whipple's disease

Abstract

We report four patients with pancreatic fistulas that failed to respond to conservative treatment. The fistulas were closed by endoscopic injection of N-butyl-2-cyanoacrylate (Histoacryl) diluted with an oily contrast agent (Lipiodol). A literature review revealed 32 similar cases in which endoscopic treatment with fibrin sealants (n = 11) or cyanoacrylate (n = 21) was used to close the fistulas. Based on our own experience and the literature review, we conclude that endoscopic sealing of pancreatic fistulas can be performed safely and effectively by experienced endoscopists in a tertiary centre. The procedure seems useful in the management of complicated pancreatic fistulas which do not respond to conservative treatment and may obviate the need for surgery.