Diagnostic Accuracy Of 18F-FDG Research Articles

Comparison of 18F-FDG PET/MR and PET/CT for pretreatment TNM staging of hilar cholangiocarcinoma.

18F-FDG PET/MR has been applied to the diagnosis and preoperative staging in various tumor types; however, reports using PET/MR in hilar cholangiocarcinoma (HCCA) are rare. We investigated the value of PET/MR for preoperative staging and compared it with PET/CT in HCCA. Fifty-eight patients with HCCA confirmed by pathology were retrospectively analyzed. 18F-FDG PET/CT imaging was performed first, followed with whole-body PET/MR imaging. SUVmax of tumor and normal liver tissue were measured. Paired T test was used to compare SUVmax of tumor and normal liver tissue of PET/CT and PET/MR. In addition, McNemar test was used to compare the accuracy of TNM staging and Bismuth-Corlette typing between PET/CT and PET/MR. There was no significant difference in SUVmax between PET/CT and PET/MR in primary tumor lesions (6.6 ± 5.5 vs. 6.8 ± 6.2, P = 0.439). SUVmax of PET/CT and PET/MR in normal liver parenchyma was significantly different (3.0 ± 0.5 vs. 2.1 ± 0.5, P < 0.001). The accuracy of PET/MR in diagnosing T staging and N staging was significantly higher than those of PET/CT (72.4% vs. 58.6%, P = 0.022 and 84.5% vs. 67.2%, P = 0.002). There was no significant difference between PET/CT and PET/MR in M staging (94.8% vs. 98.3%, P = 0.5). The classification accuracy of PET/MR in Bismuth-Corlette was significantly higher than that of PET/CT (89.7% vs. 79.3%), P = 0.031. The diagnostic accuracy of 18F-FDG PET/MR was superior to that of PET/CT in preoperative T staging, N staging, and Bismuth-Corlette classification of HCCA. In M staging, the diagnostic accuracy of PET/MR was similar to that of PET/CT.

Diagnostic accuracy of 18F-FDG PET/TC for the characterization of adrenal lesions in a heterogeneous population

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Abstract P5-01-02: Diagnostic Accuracy of 18F-FDG PET/CT plus Contrast-Enhanced MRI for Axillary Lymph Node Metastasis Involved in Invasive Ductal Carcinoma

Abstract Background: Positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) are useful imaging modalities for the preoperative nodal staging in breast cancer; however, clinical evidence demonstrating the diagnostic accuracy of the combination of PET/CT and MRI is limited. The purpose of this study is to establish a clinical prediction model based on PET/CT plus contrast-enhanced MRI for ALN metastasis, and explore the possibility of non-invasive patients’ risk stratification using the PET/CT plus MRI model preoperatively. Methods: A total of 361 women (370 axillae; mean age, 56 years ± 12 [standard deviation]) who underwent surgery for primary invasive ductal carcinoma at a single institution between April 2017 and March 2020 were evaluated. Subjects were divided into two cohorts: a derivation cohort (n = 333) and a validation cohort (n = 37). In the derivation cohort, we constructed a prediction model with logistic regression to estimate the potential explanatory variables obtained by PET/CT, MRI, and preoperative core-needle biopsy. Using a simple integer risk score, patients were divided into low-risk and high-risk groups. We assessed the predictive ability of the PET/CT plus MRI model using the area under the curve (AUC), and internal validation was achieved by risk scoring system in the validation cohort. Results: The PET/CT plus MRI model included five predictor variables: maximum standardized uptake value of primary tumor and ALN, primary tumor size, ALN cortical thickness, and histological grade. The PET/CT plus MRI model had significantly improved AUC of 0.867 (p &amp;lt; 0.05) as compared to those of the PET/CT model (AUC = 0.821) and MRI model (AUC = 0.815). We assigned the weighted scores to each retained variables in the PET/CT plus MRI model, and determined the optimal cut-off value of 7 (range, 0−17). In the derivation and validation cohorts, 55% and 65% of the patients were classified as low-risk by the risk scoring system, with negative predictive values of 97% and 100%, respectively. Conclusions: Our findings demonstrated a better diagnostic accuracy of the clinical prediction model utilizing both PET/CT and MRI than previous models based on either PET/CT or MRI, and the negative predictive value of 97% was not inferior to that of sentinel lymph node biopsy. Thus, the preoperative risk evaluation of axillary lymph node macrometastasis using our integrated model could be useful while considering individualized therapy for patients with invasive ductal breast cancer. Further validation should be performed for clinical applications. Citation Format: Shun Kawaguchi, Nobuko Tamura, Kiyo Tanaka, Yoko Kobayashi, Junichiro Sato, Keiichi Kinowaki, Masato Shiiba, Makiko Ishihara, Hidetaka Kawabata. Diagnostic Accuracy of 18F-FDG PET/CT plus Contrast-Enhanced MRI for Axillary Lymph Node Metastasis Involved in Invasive Ductal Carcinoma [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-01-02.

Improving the imaging diagnostic strategy for pulmonary artery masses based on 18F-FDG PET/CT integrated with CTPA.

To evaluate the diagnostic accuracy of computed tomography pulmonary angiography (CTPA) and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for pulmonary artery (PA) masses. Of 2889 patients with PA filling defects of PA on CTPA, 79 consecutive patients suspicious for PA malignancy who subsequently underwent 18F-FDG PET/CT were enrolled. All masses were diagnosed on the basis of pathological findings or clinical imaging follow-up. For each mass, morphological CT signs, standardized uptake value (SUVmax and SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) on 18F-FDG PET/CT were used as diagnostic markers. Expansive growth, irregular margin, invasion, CT contrast uptake, and wall eclipse sign were strongly associated with the malignant nature of masses. The coexistence of at least 5 CT signs perfectly identified malignant masses, whereas the detection of no more than 4 CT signs did not accurately discriminate between the natures of masses. Mean SUVmax, SUVmean, MTV, and TLG values were significantly higher in malignant masses compared to those in benign masses. The diagnostic accuracy of 18F-FDG PET/CT parameters (SUV, MTV, and TLG) was excellent in detecting malignant masses. Among patients with 3 or 4 pathological CT signs, SUVmax > 3.4 significantly increased the identification of malignancies. CTPA is a useful imaging modality for diagnosing PA masses, especially when at least 5 abnormal CT signs are identified. Similarly, 18F-FDG PET/CT accurately identified malignant masses and provided additional valuable information on diagnostic uncertainties after CTPA.

Impact of 18F-FDG PET/CT on treatment of patients with differentiated thyroid carcinoma, negative 131I whole body scan and elevated serum thyroglobulin.

Objective(s): 18F-FDG PET/CT is increasingly performed in patients with differen-tiated thyroid cancer. The aim of this study was to assess the clinical impact of 18F-FDG PET/CT on the management of patients with differentiated thyroid carcinoma who had elevated serum thyroglobulin (Tg) and negative 131I whole body scan (WBS). Methods:67 patients with differentiated thyroid carcinoma were included in this study. The findings of 18F-FDG PET/CT imaging were compared with histo-pathology, follow up imaging, or clinical follow-up results. The diagnostic accuracy of 18F-FDG PET/CT was evaluated for the entire patient group and for those patients with stimulated serum thyroglobulin levels of less than 5, 5–10, and more than 10 pmol/L as well as for local recurrences and metastases sites. The impact of 18F-FDG PET/CT on therapeutic management was also evaluated. Results:30/67 patients had positive findings on 18F-FDG PET/CT; 28 were true-positive and 2 were false-positive. 18F-FDG PET/CT results were true-negative in 36 patients and false-negative in 1 patient. The overall sensitivity, specificity, accuracy, PPV and NPV of 18F-FDG PET/CT were, 96.5%, 94.5%, 95.5%, 93.3%, and 97.2% respectively. Positive 18F-FDG PET/CT findings were directly correlated with stimulated serum thyroglobulin levels, 7.1% had Tg between 5–10, and 92.9% had Tg greater than 10 pmol/L. 18F-FDG PET/CT had a high or moderate impact on treatment management in 28 (41.8%) of patients.Conclusion: 18F-FDG PET/CT is able to improve diagnostic accuracy and have management impact in a therapeutically relevant way in patients with differentiated thyroid carcinoma who present with rising thyroglobulin level, negative 131I WBS, and clinical suspicion of recurrent disease.

Impact of 18F-FDG PET/CT, CT and EBUS/TBNA on preoperative mediastinal nodal staging of NSCLC

BackgroundStaging of non-small-cell lung cancer (NSCLC) is a multidisciplinary process involving imaging, endoscopic and surgical techniques. This study aims at investigating the diagnostic accuracy of 18F-FDG PET/CT, CT scan, and endobronchial ultrasound/transbronchial needle aspirate (EBUS/TBNA) in preoperative mediastinal lymph nodes (MLNs) staging of NSCLC.MethodsWe identified all patients who were diagnosed with NSCLC at the King Hussein Cancer Center in Amman, Jordan, between July 2011 and December 2017. We collected their relevant clinical, radiological, and histopathological findings. The per-patient analysis was performed on all patients (N = 101) and then on those with histopathological confirmation (N = 57), followed by a per-lymph-node-station basis overall, and then according to distinct N-stage categories.Results18F-FDG PET/CT, in comparison to CT, had a better sensitivity (90.5% vs. 75%, p = 0.04) overall and in patients with histopathological confirmation (83.3% vs. 54.6%), and better specificity (60.5% vs. 43.6%, p = 0.01) overall and in patients with histopathological confirmation in MLN staging (60.6% vs. 38.2%). Negative predictive value of mediastinoscopy, EBUS/TBNA, and 18F-FDG PET/CT were (87.1%), (90.91%), and (83.33%) respectively. The overall accuracy was highest for mediastinoscopy (88.6%) and EBUS/TBNA (88.2%), followed by 18F-FDG PET/CT (70.2%). Dividing patients into N1 disease vs. those with N2/N3 disease yielded similar findings. Comparison between 18F-FDG PET/CT and EBUS/TBNA in patients with histopathological confirmation shows 28 correlated true positive and true negative findings with final N-staging. In four patients, 18F-FDG PET/CT detected metastatic MLNs that would have otherwise remained undiscovered by EBUS/TBNA alone. Lymph nodes with a maximal standardized uptake value (SUVmax) more than 3 were significantly more likely to be true-positive.ConclusionMultimodality staging of the MLNs in NSCLC is essential to provide accurate staging and the appropriate treatment. 18F-FDG PET/CT has better overall diagnostic utility when compared to the CT scan. The NPV of 18F-FDG PET/CT in MLNs is reliable and comparable to the NPV of EBUS/TBNA. SUVmax of MLNs can help in predicting metastases, but nevertheless, a positive 18F-FDG PET/CT MLNs particularly if such a result would change the treatment plan, should be verified histopathologically.

Diagnostic accuracy of18F-FDG PET/CT in the evaluation of recurrent ovarian cancer

Objective: Ovarian cancer recurrence is often a major problem for patients who have undergone treatment. This prospective study was undertaken to evaluate the diagnostic accuracy of positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG)/ computed tomography (CT) in patients with suspected for ovarian cancer recurrence.&#x0D; Methods: A total of 43 women who underwent surgery or chemotherapy for ovarian cancer were enrolled in this study. They underwent18 F-FDG PET/CT scan due to raised CA-125 levels, clinical suspicion of ovarian cancer recurrence, or alterations detected on CT.18 F-FDG PET/CT findings for the women were compared with the final diagnosis.&#x0D; Results: CA-125 was elevated in 13 patients, while 34 patients presented with alterations on CT, and 9 patients presented with both results’ positivity. 17 patients confirmed to have an ovarian cancer recurrence, all with abnormal findings on PET/ CT. 20 patients remained disease-free during follow-up, all with normal PET/CT findings. There were 9 patients with raised CA-125 levels and normal conventional imaging, all with positive18 F-FDG PET/CT. Among the 30 patients with normal CA-125 levels, 9 patients presented with a positive PET/CT scan. Lymph nodes were the most frequent site. Its sensitivity, specificity, positive predictive value, and negative predictive valuewere 94%, 91%, 77%, and 95%, respectively.&#x0D; Conclusion: 18F-FDG PET/CT is a useful modality for evaluating the cancer recurrence and extent of the disease. Lymph nodes were the most frequent site. However, there was no statistical significance found between CA-125 levels and 18F-FDG PET/CT findings.&#x0D; Bangladesh Journal of Medical Science Vol.20(2) 2021 p.302-312

Diagnostic accuracy of cardiac computed tomography and 18F-fluorodeoxyglucose with positron emission tomography/computed tomography in cardiac masses

Abstract Background Understanding the nature of cardiac masses represents a challenge for clinicians in order to select the appropriate therapeutic strategies. The diagnostic accuracy of cardiac computed tomography (CT) and 18F-fluorodeoxyglucose (18F-FDG) with positron emission tomography/CT (PET/CT) in identifying the nature of cardiac masses has not been evaluated before in a large population. Purpose To assess the diagnostic value of CT and 18F-FDG PET/CT in defining the nature of cardiac masses, integrating morphologic features and metabolic activity. Methods Out of 223 we selected a final cohort 60 patients which underwent cardiac CT scan and 18F-FDG PET/CT. All masses had histological certain, apart from thrombi, in which was defined radiologic resolution after adequate anticoagulant treatment. For each mass, eight morphologic CT signs and standardized uptake value (SUVmax, SUVmean), metabolic tumour volume (MTV) and total lesion glycolysis (TLG) in 18F-FDG PET, were evaluated. Results Twenty patients had benign cardiac masses and 40 patients malignant cardiac masses. Irregular tumour margins, pericardial effusion, invasions, solid nature of the mass, mass diameter, TC contrast up-take and pre-contrast characteristics were strongly associated with the malignant nature of cardiac masses (p&amp;lt;0.001). Additionally, the presence of at least four CT signs was able to discriminate malignancies, withsensitivity of 95% and specificity of 95% (AUC=0.988, 95% CI 0.969–1). The mean value of SUVmax, SUVmean, MTV and TLG was significantly higher in malignant cardiac masses than in benign lesions (p&amp;lt;0.001). ROC curve for diagnostic accuracy of 18F-FDG PET/CT parameters in detecting malignant lesions showed an excellent performance of SUV (AUC=0.948, 95% CI 0.891–1), MTV (AUC=0.928, 95% CI 0.841–1) and TLG (AUC=0.961, 95% CI 0.902–1). Conclusions In patients with cardiac masses, cardiac computed tomography and 18F-FDG PET/CT findings provide independent and incremental prognostic information regarding their nature. A systematic use of CT and 18F-FDG PET/CT is therefore useful for diagnostic and therapeutic purposes. PET-CT evaluation of cardiac masses Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): S. Orsola Malpighi Hospital, University of Bologna

Role of 18F-FDG-PET/CT in patients with differentiated thyroid cancer with biochemical incomplete or indeterminate response to treatment

ObjectivesTo assess the value of 18F-FDG-PET/CT for detecting recurrent/persistent disease in patients with biochemical incomplete (BIR) or indeterminate response (IR) and to assess the impact of 18F-FDG-PET/CT on the therapeutic management of these patients. MethodsThe study included patients with BIR, in whom 18F-FDG PET/CT was used within the diagnostic algorithm from our database. Patients with IR referred to our hospital with the 18F-FDG PET/CT already performed were also enrolled. All patients had neck ultrasonography with no structural changes. A change in therapeutic approach was defined as repeat surgery; administration of external beam radiotherapy; and/or the start of systemic therapy. ResultsSixty patients (85% women) aged 18–86 years were enrolled in this retrospective study. Of these, 75% had BIR and 25% IR. Increased FDG uptake suggesting locoregional lesions was seen in 40% of patients. Sensitivity, specificity, and diagnostic accuracy of 18F-FDG PET/CT to detect local disease were 95%, 87.5% and 90% respectively. The therapeutic approach was modified in 50% of patients with locoregional lesions. ConclusionsOur study confirmed that 18F-FDG-PET/CT is a useful tool for detecting locoregional recurrence in thyroid cancer patients with BIR or IR with conflicting findings in standard diagnostic procedures. In 50% of patients with locoregional lesions, there was an immediate change in the treatment approach.

The diagnostic value of 18F-FDG PET/CT in identifying the causes of fever of unknown origin

This study investigated the clinical significance of 18F-fluorodeoxyglucose positron emission tomography / computed tomography (18F-FDG PET/CT) in identifying the causes of fever of unknown origin (FUO). Patients with a fever who received an 18F-FDG PET/CT examination were retrospectively selected. The means of the two groups were compared using an independent-samples t-test. Among the 89 included patients, 66 were diagnosed using 18F-FDG PET/CT. The sensitivity, specificity and diagnostic accuracy of 18F-FDG PET/CT for the diagnosis of patients with FUO were 84.5%, 25.8%, and 64.0%, respectively. The detection rates of 18F-FDG PET/CT for neoplastic diseases, infectious diseases and non-infectious inflammatory diseases were 100%, 61.3%, and 75%, respectively. The difference in C-reactive protein (CRP) levels between the two groups was statistically significant. 18F-FDG PET/CT has great clinical importance in diagnosing and identifying causes of FUO and improves the accuracy of FUO diagnosis when combined with serum CRP levels.

Role of 18F-FDG-PET/CT in patients with differentiated thyroid cancer with biochemical incomplete or indeterminate response to treatment

ObjectivesTo assess the value of 18F-FDG-PET/CT for detecting recurrent/persistent disease in patients with biochemical incomplete (BIR) or indeterminate response (IR) and to assess the impact of 18F-FDG-PET/CT on the therapeutic management of these patients. MethodsThe study included patients with BIR, in whom 18F-FDG PET/CT was used within the diagnostic algorithm from our database. Patients with IR referred to our hospital with the 18F-FDG PET/CT already performed were also enrolled. All patients had neck ultrasonography with no structural changes. A change in therapeutic approach was defined as repeat surgery; administration of external beam radiotherapy; and/or the start of systemic therapy. ResultsSixty patients (85% women) aged 18–86 years were enrolled in this retrospective study. Of these, 75% had BIR and 25% IR. Increased FDG uptake suggesting locoregional lesions was seen in 40% of patients. Sensitivity, specificity, and diagnostic accuracy of 18F-FDG PET/CT to detect local disease were 95%, 87.5% and 90% respectively. The therapeutic approach was modified in 50% of patients with locoregional lesions. ConclusionsOur study confirmed that 18F-FDG-PET/CT is a useful tool for detecting locoregional recurrence in thyroid cancer patients with BIR or IR with conflicting findings in standard diagnostic procedures. In 50% of patients with locoregional lesions, there was an immediate change in the treatment approach.

P1806Diagnosis of isolated cardiac sarcoidosis using FDG-PET/CT on the basis of new guidelines

Abstract Introduction Sarcoidosis is a systemic inflammatory disease which can involve any organs. The reported prevalence of isolated cardiac sarcoidosis (CS) varies widely because of the lack of an agreed definition of isolated CS (iCS). ICS was newly defined in the new guidelines for CS by Japanese Circulation Society. Purpose We aimed to examine the diagnostic accuracy of 18F-FDG PET/CT and the ratio of iCS in the whole CS by reviewing the patients with suspected CS undergoing the whole-body and cardiac FDG PET/CT scans. Methods We retrospectively reviewed 74 consecutive patients undergoing 18F-FDG PET/CT from 2013 to 2018 (mean age 60±14 years, 37 male) without the initiation of corticosteroid. Myocardial FDG uptake in CS was defined as a “focal” or “focal on diffuse” pattern. Systemic sarcoidosis (sCS) and iCS were diagnosed according to guidelines for the diagnosis and treatment of CS by Japanese Circulation Society. In short, iCS was diagnosed clinically when no clinical findings of sarcoidosis in any other organs and FDG uptake in heart were shown in addition to the following three of four criteria: high-grade atrioventricular block or fatal ventricular arrhythmia, structural abnormality, left ventricular contractile dysfunction, and delayed Gadolinium enhancement of myocardium on MRI. Results Of 31 patients with extra-cardiac sarcoidosis, 10 already met the diagnostic criteria of sCS before undergoing 18F-FDG PET/CT and 11 was newly diagnosed as sCS after FDG PET/CT. Of the remaining 43 without extra-cardiac sarcoidosis, 18 had FDG uptake in heart. Of 18 with FDG uptake in heart, iCS was diagnosed in 7, and sCS in 3 with extra-cardiac uptake of FDG as well as myocardium. Finally, 24 and 7 patients met the criteria of sCS and iCS based on the guideline, respectively. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FDG PET/CT for CS including sCS and iCS were 90, 87, 88, 85, and 92%, respectively. Conclusion The ratio of iCS on the basis of new guidelines for diagnosis and treatment of CS was 22% of the whole CS.

Metabolic pattern analysis of 18F-FDG PET as a marker for Parkinson's disease: a systematic review and meta-analysis.

A large number of articles have assessed the diagnostic accuracy of the metabolic pattern analysis of [18F]fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) in Parkinson's disease (PD); however, different studies involved small samples with various controls and methods, leading to discrepant conclusions. This study aims to consolidate the available observational studies and provide a comprehensive evaluation of the clinical utility of 18F-FDG PET for PD. The methods included a systematic literature search and a hierarchical summary receiver operating characteristic approach. Sensitivity analyses according to different pattern analysis methods (statistical parametric mapping versus scaled subprofile modeling/principal component analysis) and control population [healthy controls (HCs) versus atypical parkinsonian disorder (APD) patients] were performed to verify the consistency of the main results. Additional analyses for multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) were conducted. Fifteen studies comprising 1446 subjects (660 PD patients, 499 APD patients, and 287 HCs) were included. The overall diagnostic accuracy of 18F-FDG in differentiating PD from APDs and HCs was quite high, with a pooled sensitivity of 0.88 [95% confidence interval (95% CI), 0.85-0.91] and a pooled specificity of 0.92 (95% CI, 0.89-0.94), with sensitivity analyses indicating statistically consistent results. Additional analyses showed an overall sensitivity and specificity of 0.87 (95% CI, 0.76-0.94) and 0.93 (95% CI, 0.89-0.96) for MSA and 0.91 (95% CI, 0.78-0.95) and 0.96 (95% CI, 0.92-0.98) for PSP. Our study suggests that the metabolic pattern analysis of 18F-FDG PET has high diagnostic accuracy in the differential diagnosis of parkinsonian disorders.

Role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in restaging and prognosis of recurrent melanoma after curative surgery.

Malignant melanoma is a highly aggressive tumor and surgical resection is the primary treatment. However, the chances of recurrence are quite high despite complete resection. The aim of study was to evaluate the 18F-fluorodeoxyglucose(18F-FDG) positron emission tomography–computed tomography (PET/CT) in detection of recurrent melanoma after curative surgery and its prognostic value. Fifty-four melanoma patients (32 women) with prior primary lesion resection were evaluated with 18F-FDG PET/CT for clinically suspicious recurrent disease. The diagnostic accuracy of 18F-FDG PET/CT (visual interpretation as well as semi-quantitative parameter) was determined on the basis of subsequent imaging and clinical follow-up. Melanoma-specific survival and risk of progression (hazard ratio [HR]) were assessed using Kaplan–Meier method and Cox regression analysis. 18F-FDG PET/CT detected recurrent diseases in 36 (66%) patients including distant metastases in 13 patients and second synchronous malignancy in 2 patients. Overall, the sensitivity, specificity, positive predictive value, and negative predictive value of 18F-FDG PET/CT were 91.2%, 80.0%, 88.6%, and 84.2%, respectively, with area under the curve of 0.86 (95% confidence interval: 0.74–0.97; P < 0.05). Positive 18F-FDG PET/CT study was associated with a significantly shorter overall survival than negative study (30.8 ± 4.6 vs. 64.5 ± 6.9 months, P < 0.05). Apart from positive 18F-FDG PET/CT scan, maximum standardized uptake value (SUVmax) >2.7 and combination of both were independently associated with an increased risk of disease progression (HR = 7.72, 21.58, and 11.37, respectively; P < 0.05). 18F-FDG PET/CT showed enhanced diagnostic performance in patients with suspicious recurrent malignant melanoma leading to appropriate management. FDG positivity along with SUVmax >2.7 provides important prognostic value in predicting the survival outcomes and assessing the risk of disease progression.

Diagnostic Accuracy of 18F-FDG PET/CT in Patients With Biochemical Evidence of Recurrent, Residual, or Metastatic Medullary Thyroid Carcinoma.

Medullary thyroid carcinoma (MTC) is a rare malignancy. Location of residual, recurrent, or metastatic disease is crucial to treatment management and outcome. We aimed to evaluate the use of F-FDG PET/CT in localizing MTC foci in patients with biochemical relapse. This is a retrospective cohort study. Review of 51 FDG PET/CT studies of 45 patients referred to restage MTC due to increased calcitonin (Ctn) and carcinoembryonic antigen (CEA) values at follow-up. FDG PET/CT diagnostic accuracy was determined through a patient-based analysis, using histology as criterion standard when available, or other imaging studies and clinical follow-up otherwise (mean, 4 years). There were 25 positive scans. Sensitivity, specificity, positive and negative predictive values, diagnostic accuracy, and positive likelihood ratio were 66.7%, 83.3%, 88.0%, 57.7%, 72.5%, and 4.0, respectively. Using a Ctn cutoff of 1000 pg/mL, sensitivity increased to 76.9%. There were significant differences of Ctn and CEA values between positive and negative FDG PET/CT (P < 0.05). Regarding true-positive studies, average SUVmax comparing locoregional and metastatic disease was at the limit of significance (P = 0.046). PET/CT can be useful to restage patients with biochemical relapse of MTC, with a better performance in higher Ctn levels. Its high positive predictive value (88%) may impact in the therapeutic management, although its low negative predictive value (57.7%) makes strict follow-up mandatory in examinations without pathologic findings.

The diagnostic accuracy of 18F-FDG PET/CT in diagnosing fracture-related infections

Purpose18F-Fluorodeoxyglucose positron emission tomography (18F-FDG PET/CT) is frequently used to diagnose fracture-related infections (FRIs), but its diagnostic performance in this field is still unknown. The aims of this study were: (1) to assess the diagnostic performance of qualitative assessment of 18F-FDG PET/CT scans in diagnosing FRI, (2) to establish the diagnostic performance of standardized uptake values (SUVs) extracted from 18F-FDG PET/CT scans and to determine their associated optimal cut-off values, and (3) to identify variables that predict a false-positive (FP) or false-negative (FN) 18F-FDG PET/CT result.MethodsThis retrospective cohort study included all patients with suspected FRI undergoing 18F-FDG PET/CT between 2011 and 2017 in two level-1 trauma centres. Two nuclear medicine physicians independently reassessed all 18F-FDG PET/CT scans. The reference standard consisted of the result of at least two deep, representative microbiological cultures or the presence/absence of clinical confirmatory signs of FRI (AO/EBJIS consensus definition) during a follow-up of at least 6 months. Diagnostic performance in terms of sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) was calculated. Additionally, SUVs were measured on 18F-FDG PET/CT scans. Volumes of interest were drawn around the suspected and corresponding contralateral areas to obtain absolute values and ratios between suspected and contralateral areas. A multivariable logistic regression analysis was also performed to identify the most important predictor(s) of FP or FN 18F-FDG PET/CT results.ResultsThe study included 156 18F-FDG PET/CT scans in 135 patients. Qualitative assessment of 18F-FDG PET/CT scans showed a sensitivity of 0.89, specificity of 0.80, PPV of 0.74, NPV of 0.91 and diagnostic accuracy of 0.83. SUVs on their own resulted in lower diagnostic performance, but combining them with qualitative assessments yielded an AUC of 0.89 compared to an AUC of 0.84 when considering only the qualitative assessment results (p = 0.007). 18F-FDG PET/CT performed <1 month after surgery was found to be the independent variable with the highest predictive value for a false test result, with an absolute risk of 46% (95% CI 27–66%), compared with 7% (95% CI 4–12%) in patients with 18F-FDG PET/CT performed 1–6 months after surgery.ConclusionQualitative assessment of 18F-FDG PET/CT scans had a diagnostic accuracy of 0.83 and an excellent NPV of 0.91 in diagnosing FRI. Adding SUV measurements to qualitative assessment provided additional accuracy in comparison to qualitative assessment alone. An interval between surgery and 18F-FDG PET/CT of <1 month was associated with a sharp increase in false test results.

P4193The real diagnostic accuracy of 18F-FDG PET/CT in patients with suspected cardiac implantable electronic device infective endocarditis: a meta-analysis

P4193The real diagnostic accuracy of 18F-FDG PET/CT in patients with suspected cardiac implantable electronic device infective endocarditis: a meta-analysis

Differential diagnostic value of 18F-FDG PET/CT for benign and malignant vertebral compression fractures: comparison with magnetic resonance imaging.

PurposeThe purpose of this study was to evaluate the differential diagnostic value of 2-[fluorine-18]-fluoro-2-deoxy-d-glucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) for benign and malignant vertebral compression fractures (VCFs), where the diagnostic accuracy of 18F-FDG PET/CT was compared with magnetic resonance imaging (MRI).Patients and methodsBetween 2015 and 2017, we retrospectively evaluated 87 patients with 116 VCFs. MRI was performed in all the 87 patients, whereas 18F-FDG PET/CT was executed in 51 patients. Three malignant features (convex posterior cortex, epidural mass formation, and pedicle enhancement) from MRI and the maximum standardized uptake value (SUVmax) from 18F-FDG PET/CT were evaluated in benign and malignant VCFs, respectively. Sensitivity, specificity, positive predictive value, and negative predictive value of MRI and 18F-FDG PET/CT were compared in the differentiation of malignant from benign VCFs.ResultsThe results of our investigation showed that the sensitivity and specificity for predicting malignant VCFs were 75.6% and 77.3% for convex posterior cortex, 82.9% and 813% for epidural mass formation, and 85.7% and 70.8% for pedicle enhancement. 18F-FDG PET/CT demonstrated higher sensitivity (100%) but lower specificity (38.9%) as compared to MRI with regard to differentiation between benign and malignant VCFs. A significant difference in the SUVmax values was observed between the benign and malignant fractures (2.9 ± 1.0 vs 5.0 ± 1.8, P < 0.01). Besides the value of SUVmax, it has been noticed that the FDG uptake pattern differed in malignant and benign fractures.ConclusionSignificant MRI findings such as convex posterior cortex, epidural mass formation, and pedicle enhancement are highly suggestive of malignancy. 18F-FDG PET/CT reliably differentiated the fractures of malignant from benign based on both SUVmax and 18F-FDG uptake pattern. In a situation where MRI findings are not diagnostic, 18F-FDG PET/CT provides additional information as it has high sensitivity and is semiquantitative.

The Diagnostic Accuracy of 18F-FDG PET/CT in Prostate Cancer: A Systemic Review and Meta-analysis

Objectives: A systematic review process was adopted to derive more robust estimates of the diagnostic accuracy of 18F-fluorodeoxyglucose(18F-FDG) positron emission tomography /computed tomography (PET/CT) for prostate cancer we pooled published studies. Methods: A comprehensive literature search about published studies till November 2017 was performed. Methodological quality of each study was assessed. A meta-analysis was used to analyze the sensitivity, specificity, diagnostic odds ratio (DOR), area under the curve (AUC), summary receiver operating characteristic (sROC) curve and Ca* indexes with statistical software. Results: Ten articles including 364 patients and 505 lesions, which published between 2009 and 2017, met the inclusion criteria for the meta-analysis. The pooled sensitivity and specificity of 18F-FDG PET-CT in prostatic cancer were 0.65 (95% CI, 0.47-0.79) and 0.85 (95% CI, 0.71-0.93), respectively. The overall PLR, NLR and DOR were 4.3 (95% CI, 2.0-9.2), 0.41 (95% CI, 0.25-0.68) and 10 (95% CI, 3-32), respectively. The area under the summary ROC curve was 0.84. There is not exist publication bias in the included studies according to the Deek’s test. Conclusions: The results of our meta-analysis suggested that 18F-FDG PET-CT were imaging methods with high accuracy in differential diagnosis of prostate cancer patients.

Does Antibiotic Treatment Affect the Diagnostic Accuracy of 18F-FDG PET/CT Studies in Patients with Suspected Infectious Processes?

18F-FDG PET/CT plays a significant role in the assessment of various infectious processes. Patients with suspected or known sites of infection are often referred for 18F-FDG imaging while already receiving antibiotic treatment. The current study assessed whether antibiotic therapy affected the detectability rate of infectious processes by 18F-FDG PET/CT. Methods: A 5-y retrospective study of all adult patients who underwent 18F-FDG PET/CT in search of a focal source of infection was performed. The presence, duration, and appropriateness of antibiotic treatment before 18F-FDG imaging were recorded. Diagnosis of an infectious process was based on microbiologic or pathologic data as well as on clinical and radiologic follow-up. Results: Two hundred seventeen patients underwent 243 PET/CT studies in search of a focal source of infection and were included in the study. Sixty-seven studies were excluded from further analysis because of a final noninfectious etiology or lack of further follow-up or details regarding the antibiotic treatment. The final study population included 176 18F-FDG PET/CT studies in 153 patients (107 men, 46 women; age range, 18-86 y). One hundred nineteen studies (68%) were performed in patients receiving antibiotic therapy for a range of 1-73 d. A diagnosis of infection was made in 107 true-positive cases (61%), including 63 studies (59%) in patients receiving appropriate antibiotic therapy started before the performance of the 18F-FDG PET/CT study. There were 52 true-negative (29%) and 17 false-positive (10%) 18F-FDG PET/CT studies. No false-negative results were found. Conclusion:18F-FDG PET/CT correctly identified foci of increased uptake compatible with infection in most patients, including all patients receiving appropriate antimicrobial therapy, with no false-negative cases. On the basis of the current study results, the administration of antibiotics appears to have no clinically significant impact on the diagnostic accuracy of 18F-FDG PET/CT performed for evaluation of known or suspected infectious processes.