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Background: Little data exists on the association of missed care opportunities (MCOs) in children referred for nuclear medicine/nuclear oncology imaging examinations and socioeconomic disparities., Objective: To determine the prevalence of MCOs in children with lymphoma/leukemia scheduled for fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) and the impact of sociodemographic factors and Child Opportunity Index (COI)., Materials and Methods: Retrospective analysis of MCOs in children with lymphoma/leukemia scheduled for FDG-PET/CT (2012 to 2022) was performed. In univariate analysis, patient, neighborhood, and appointment data were assessed across MCOs and completed appointments. Logistic regression evaluated independent effects of patient-, neighborhood-, and appointment-level factors with MCOs. Two-sided P-value < .05 was considered statistically significant., Results: In 643 FDG-PET/CT appointments (n = 293 patients; median age 15 years (IQR 11.0-17.0 years); 37.9% female), there were 20 MCOs (3.1%) involving 16 patients. Only 8.2% appointments involved Black/African American non-Hispanic/Latino patients, yet they made up a quarter of total MCOs. Patients living in neighborhoods with very low or low COI experienced significantly higher MCOs versus zip codes with very high COI (6.9% vs. 0.8%; P = 0.02). Logistic regression revealed significantly increased likelihood of MCOs for patients aged 18 to 21 [odds ratio (OR) 4.50; 95% CI 1.53-13.27; P = 0.007], Black/African American non-Hispanic/Latino (OR 3.20; 95% CI 1.08-9.49; P = 0.04), zip codes with very low or low COI (OR 9.60; 95% CI 1.24-74.30; P = 0.03), and unknown insurance status., Conclusion: Children with lymphoma/leukemia, living in zip codes with very low or low COI, and who identified as Black/African American non-Hispanic/Latino experienced more MCOs. Our study supports the need to address intersecting sociodemographic, neighborhood, and health system factors that will improve equitable access to necessary healthcare imaging for children., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Aim: To evaluate 18 F-FDG-PET/CT for suspected ovarian cancer relapse with negative/inconclusive conventional imaging, or restaging potentially resectable ovarian cancer relapse., Material and Methods: Thirty-six cases and 140 locations were studied. PET/CT, ceCT and serum CA-125 was conducted in all cases. Nineteen cases were requested for restaging, 17 for suspected relapse. We compared ceCT and PET/CT, assessed by histopathology or radiological follow-up, calculating sensitivity (S) and positive predictive value (PPV) by cases and lesions. We evaluated the correlation between size, number, uptake of the lesions and CA-125. We conducted survival analysis, using ROC curves to calculate the optimal cut-off of SUVmax for survival prediction. We checked whether PET/CT modify the therapeutic attitude vs. conventional imaging., Results: PET/CT and ceCT were concordant in 12 cases: 11 positives (30 lesions), all confirmed. There was 1 FN. In the 24 non-concordant, PET/CT was positive in 19 (97 lesions); ceCT in 21 (59 lesions); 54% of the lesions were concordant. Overall, PET/CT detected 127 lesions, with S=97% and PPV=100%. ceCT detected 89 lesions, with S=61% and PPV=90%. No significant correlation was found between CA-125 and the other parameters. PET/CT detected 10 positive cases, with normal CA-125. PET/CT modified therapeutic management in 15 cases. Significant differences were found in survival with SUVmax=11.8 CONCLUSIONS: PET/CT plays an important role in ovarian cancer relapse, with sensitivity and PPV higher than ceCT, modified therapeutic management in up to 42% of cases, and could be a valuable tool for predicting survival., (Copyright © 2020. Published by Elsevier España, S.L.U.)

Objective: The maximum standardized uptake value (SUVmax) derived by positron emission tomography-computed tomography (PET/CT) can be an index of biological tumor aggressiveness, which is assessed using noninvasive tools before the treatment of epithelial ovarian cancer (EOC). This study aimed to evaluate the prognostic value of the pretreatment SUVmax in patients with EOC., Materials and Methods: We reviewed the data of patients with EOC who underwent pretreatment 18F-FDG PET/CT between June 2006 and September 2016. The relationships between pretreatment SUVmax and histological subtypes of EOC were determined. Moreover, progression-free survival (PFS) and overall survival (OS) were evaluated according to the pretreatment SUVmax. Risk factors associated with progression or death were also analyzed., Results: Of 148 patients, 66 (44.6%), 11 (7.4%), 34 (23.0%), 19 (12.8%), 15 (10.1%), and three (2.0%) were diagnosed with high-grade serous carcinoma (HGSC), low-grade serous carcinoma (LGSC), clear cell carcinoma (CCC), endometrioid carcinoma, mucinous carcinoma, and others, respectively. The median SUVmax was marginally lower in LGSC (6.80 vs. 10.5; P = 0.059) and significantly lower in CCC (5.92 vs. 10.5; P = 0.001) than in HGSC. A high pretreatment SUVmax (≥9.30) was a prognostic factor for OS in patients with LGSC (P = 0.046). Furthermore, multivariate analysis revealed that a high SUVmax (≥5.85) was an independent prognostic factor for OS (P = 0.046) in patients with CCC. However, a high SUVmax (≥7.77) was a poor predictor of PFS and OS in patients with EOC (P = 0.156 and P = 0.158, respectively)., Conclusion: Our findings suggest that the pretreatment SUVmax is not only an independent predictor of survival in patients with CCC but also a significant predictor of survival in patients with LGSC., Competing Interests: Declaration of competing interest The authors have no conflicts of interest relevant to this article., (Copyright © 2021. Published by Elsevier B.V.)

Background: To assess the predictive value of 18 F-fluorodeoxyglucose positron-emission tomography (FDG-PET/CT) in detecting mediastinal lymph node metastasis with histopathologic verification in breast cancer (BC) patients., Materials and Methods: Between February 2012 and October 2019, 37 BC patients who underwent histopathological verification for FDG-PET positive mediastinal lymph nodes were retrospectively analyzed. Nine patients (24%) were screened before beginning treatment, while 27 (76%) were screened at the time of disease progression, an average of 39 months after completion of initial treatment., Results: The histopathologic diagnosis revealed lymph node metastasis from BC in 15 patients (40%) and benign disease in 22 patients (60%). The standardized uptake value (SUV max ) of mediastinal lymph nodes was significantly higher in patients with lymph node metastasis compared to those with benign histology (9.0 ± 3.5 vs. 5.9 ± 2.4; P = 0.007). The cut-off value of SUV max after the ROC curve analysis for pathological lymph node metastasis was 6.4. Two of the 15 patients with mediastinal SUV max  ≤ 6.4 and 13 of the 22 patients with SUV max  > 6.4 had lymph node metastasis. Age and pathological findings were prognostic factors for overall survival in univariate analysis. The treatment decision was changed in 19 patients (51%) after mediastinoscopic evaluation of the entire cohort., Conclusions: This is the first study to support the need for pathologic confirmation of a positive PET/CT result following evaluation of mediastinal lymph nodes for staging BC, either at initial diagnosis or at the time of progression. Treatment decisions were consequently altered for nearly half of the patients., Competing Interests: Declaration of competing interest All authors declare no conflicts of interest related to this article., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objectives: The reversibility of interstitial lung disease (ILD) in SSc is difficult to assess by current diagnostic modalities and there is clinical need for imaging techniques that allow for treatment stratification and monitoring. 18F-Fluorodeoxyglucose (FDG) PET/CT scanning may be of interest for this purpose by detection of metabolic activity in lung tissue. This study aimed to investigate the potential role of 18F-FDG PET/CT scanning for the quantitative assessment of SSc-related active ILD., Methods: 18F-FDG PET/CT scans and high resolution CT scans of eight SSc patients, including five with ILD, were analysed. For comparison, reference groups were included: eight SLE patients and four primary Sjögren's syndrome (pSS) patients, all without ILD. A total of 22 regions of interest were drawn in each patient at apical, medial and dorsobasal lung levels. 18F-FDG uptake was measured as mean standardized uptake value (SUVmean) in each region of interest. Subsequently, basal/apical (B/A) and medial/apical (M/A) ratios were calculated at patient level (B/A-p and M/A-p) and at tissue level (B/A-t and M/A-t)., Results: SUVmean values in dorsobasal ROIs and B/A-p ratios were increased in SSc with ILD compared with SSc without ILD (P = 0.04 and P = 0.07, respectively), SLE (P = 0.003 and P = 0.002, respectively) and pSS (P = 0.03 and P = 0.02, respectively). Increased uptake in the dorsobasal lungs and increased B/A-t ratios corresponded to both ground glass and reticulation on high resolution CT., Conclusion: Semi-quantitative assessment of 18F-FDG PET/CT is able to distinguish ILD from non-affected lung tissue in SSc, suggesting that it may be used as a new biomarker for SSc-ILD disease activity., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Rheumatology.)

Objective: To evaluate 18F-fluorodeoxyglucose (FDG) PET/CT in the assessment of disease activity, extent of the disease and response to therapy in relapsing polychondritis., Methods: Twenty-five patients (9 men, 16 women) with a mean age of 38.2 years (s.d. 13.7; range 18-62), diagnosed to have relapsing polychondritis according to Damiani and Levine's modification of McAdam's criteria, who underwent PET/CT examination were included. Ten patients underwent a second PET/CT examination after therapy or during follow-up. Clinical symptoms and auxiliary examination findings were recorded. PET/CT findings were reviewed and correlated with the clinical symptoms., Results: The major symptoms were aural pain (n = 21), nasal pain (n = 10), stridor (n = 5), cough (n = 9), fever (n = 8) and laryngeal tenderness (n = 8). The initial PET/CT was positive in 23/25 patients. PET/CT revealed involvement of auricular (n = 14), nasal (n = 8), laryngeal (n = 7), tracheobronchial (n = 6) and Eustachian (n = 3) cartilages with a mean maximum standardized uptake value (SUVmax) of 4.1 (s.d. 2.5; range 1.7-12.7). Fair correlation of aural/nasal pain/stridor with FDG avidity of cartilage involvement on PET/CT was noted. The key finding was detection of asymptomatic large airway involvement in seven patients (28%). Re-examination PET in 10 patients revealed complete therapeutic response (n = 5), partial response (n = 1), stable disease (n = 1), progressive disease (n = 1) and disease recurrence (n = 2)., Conclusion: FDG PET/CT is a useful tool for the assessment of the disease activity and extent. It identified activity in clinically inaccessible sites that are of clinical significance. It is also useful in assessing treatment response and finding relapse., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Existing surveys of radiopharmaceutical doses for U.S. nuclear medicine laboratories are of limited scope and size. Dose data are important because they can be used to benchmark individual laboratories, understand geographic variations in practice, and provide source data for societal guidelines and appropriateness criteria. Diagnostic reference levels (DRLs) and achievable administered activities (AAAs) for 13 noncardiac adult gamma camera and PET/CT examinations were derived retrospectively from American College of Radiology accreditation data (January 1, 2015, to December 31, 2017). The calculated DRL and AAA are consistent with previously published surveys. The distributions of radiopharmaceutical doses across facilities are in general consistent but show variation within a particular examination. Analysis of dose distribution suggests this variation results from differences in clinical protocols, educational gaps, and/or equipment factors. The AAA for the surveyed facilities exceeds dose ranges proposed in societal practice guidelines for several common nuclear medicine studies. Compared with similar surveys from Europe and Japan, geographic variation is observed, with some doses greater and others lower than used in the United States. Overall, radiopharmaceutical dose variation within the United States and internationally, and deviation from societal guidelines, imply that these dose-related benchmarks may be used to further standardize and improve clinical practice., (© RSNA, 2019.)

Objective: Clinical joint count assessment is important for detecting synovitis but its reliability is a subject of controversy. This study was undertaken to assess the correlation of positron emission tomography (PET)-derived parameters in 68 joints with disease activity and to compare the reliability of joint counts between PET with computed tomography (CT) and clinical assessment in patients with rheumatoid arthritis (RA)., Methods: We enrolled 91 patients with active RA (69 in a development group and 22 in a validation group) who underwent concurrent 18 F-fluorodeoxyglucose ( 18 F-FDG)-PET-CT and clinical disease activity evaluation. PET-derived parameters were compared with disease activity assessed using clinical joint count parameters. A Disease Activity Score (DAS) using counts of PET-positive joints was developed, and then validation studies were performed in an independent group., Results: The number of PET-positive joints (of 28 and 68 joints) was significantly correlated with the swollen joint count (SJC) and tender joint count (TJC) and the DAS in 28 joints using the erythrocyte sedimentation rate (DAS28-ESR). Intraobserver and interobserver reliability of PET for the affected joint counts were excellent. Interobserver reliability between nuclear medicine physicians and rheumatologists was good for the SJC and TJC in both 28 joints and 68 joints. After multivariate analyses, including ESR and patient's global assessment of disease activity (PtGA) in addition to PET-derived parameters, the PET/DAS was derived as (0.063 × number of PET-positive joints in 28 joints) + (0.011 × ESR) + (0.030 × PtGA). A significant correlation between the PET/DAS and the DAS28-ESR was confirmed in the validation group (P < 0.001)., Conclusion: PET-CT could serve as a sensitive and reliable method in the evaluation of disease activity in RA patients, and may be applicable as a research tool, particularly in clinical trials., (© 2019, American College of Rheumatology.)

Hybrid imaging procedures such as single-photon emission computed tomography/computed tomography (SPECT/CT) and positron emission tomography/computed tomography (PET/CT) showed a rapid diffusion in recent years because of their high sensitivity, specificity, and accuracy, due to a more accurate localization and definition of scintigraphic findings. However, hybrid systems inevitably lead to an increase in patient radiation exposure because of the added CT component. Effective doses due to the radiopharmaceuticals can be estimated by multiplying the administered activities by the effective dose coefficients, while for the CT component the dose-length product can be multiplied by a conversion coefficient k. However, the effective dose value is subject to a high degree of uncertainty and must be interpreted as a broad, generic estimate of biologic risk. Although the effective dose can be used to estimate and compare the risk of radiation exposure across multiple imaging techniques, clinicians should be aware that it represents a generic evaluation of the risk derived from a given procedure to a generic model of the human body. It cannot be applied to a single individual and should not be used for epidemiologic studies or the estimation of population risks due to the inherent uncertainties and oversimplifications involved. Practical ways to reduce radiation dose to patients eligible for hybrid imaging involve adjustments to both the planning phase and throughout the execution of the study. These methods include individual justification of radiation exposure, radiopharmaceutical choice, adherence to diagnostic reference levels (DLR), patient hydration and bladder voiding, adoption of new technical devices (sensitive detectors or collimators) with new reconstruction algorithms, and implementation of appropriate CT protocols and exposure parameters.

Background: To investigate the value of positron emission tomography (PET) and PET/computed tomography (CT) using fluorine-18-fluorodeoxyglucose (F-FDG) in the diagnosis, staging, restaging and recurrence monitoring of Ewing sarcoma family of tumors (ESFTs), a meta-analysis was performed through systematically searching PubMed, Embase, and Cochrane Central library to retrieve articles., Methods: After screening and diluting out the articles that met inclusion criteria to be used for statistical analysis the pooled evaluation indexes including sensitivity, specificity, and diagnostic odd ratio (DOR) as well as the summary receiver operating characteristic curve (SROC) were calculated involving diagnostic data (true positive, false positive, false negative, and true negative) extracted from original studies., Results: Screening determined that out of 2007, 23 studies involving a total of 524 patients were deemed viable for inclusion in the meta-analysis. The results of the analysis showed that the sensitivity and specificity were at 86% and 80%, respectively. Additionally, a satisfactory accuracy of F-FDG PET and PET/CT was observed in detecting ESFT recurrence, lung metastasis, and osseous metastasis., Conclusion: This meta-analysis suggests that F-FDG PET and PET/CT with an extremely high accuracy could be considered a valuable method for detecting distant metastasis and post-operational recurrence of ESFT, which might have a profound impact on the development of treatment protocols for ESFT.

Background and Aim: Positron emission tomography/computed tomography(PET/CT) scans detects benign clinical conditions in addition to malignancy, and this leads to additional investigation and expenditure. The purpose of our study was to assess the endoscopic and histopathologic results of incidental 18F-FDG uptake in the GI tract., Patients and Method: We enrolled 110 patients who underwent gastroscopy/colonoscopy for incidental GI tract involvement in PET/CT. Histopathologic and endoscopic results were compared with FDG uptake level, pattern of uptake(diffuse/focal), and site of involvement., Results: In our study, 52.7% of the patients were male and the mean age was 57±11 years. Among the participants, 47.3% and 52.7% of patients had upper GI tract and colorectal involvement in PET/CT, respectively. Gastritis and colonic polyps were the most common endoscopic diagnoses that caused FDG uptake in the upper and lower GI tract, respectively. Endoscopic evaluation was normal in 23.6% of patients with pathologic FDG involvement. The rates of adenomatous polyps, malignancy, and hyperplastic polyps were 18.5%, 13.6%, and 6.8%, respectively. The mean SUVmax were higher in malignant lesions than in non-malignant lesions (14.3±8.9 vs. 9.3±5.3)(p=0.02). Diffuse or focal FDG involvement patterns on PET/CT did not help to discriminate malignancy in the GI tract., Conclusion: Malignancy was detected in only 13.6% of patients with FDG involvement in the GI tract, and the involvement pattern(diffuse/focal) and SUVmax did not differentiate malignancy., Competing Interests: The authors declare that they have no conflict of interest., (© Acta Gastro-Enterologica Belgica.)

We compared the usefulness of Tc-methyl diphosphonate (Tc-MDP) bone scintigraphy and F-fluorodeoxyglucose (FDG) for positron emission tomography/computed tomography (PET/CT) in predicting histologic response in patients with osteosarcoma receiving neoadjuvant chemotherapy (NAC).We retrospectively reviewed 62 patients with high-grade osteosarcoma who had received 2 cycles of NAC and surgery. All patients underwent Tc-MDP bone scintigraphy and F-FDG PET/CT before and after NAC. Tc-MDP uptake in the primary tumor was measured quantitatively as the maximum tumor-to-nontumor ratio (T/NTmax) and F-FDG uptake was measured as the maximum standardized uptake value (SUVmax), before and after NAC. The percent changes of T/NTmax (percent changes of the maximum tumor-to-nontumor ratio [Δ%T/NTmax]) and SUVmax (percent changes of the maximum standardized uptake value [Δ%SUVmax]) after NAC were calculated and the correlations between these parameters were evaluated. After surgery, the effects of NAC were graded histopathologically (good vs poor) and the optimum cut-off values of Δ%T/NTmax and Δ%SUVmax for predicting histologic response were assessed using the receiver operating characteristic (ROC) curve analysis.Δ%T/NTmax and Δ%SUVmax were positively correlated with each other (r = 0.494, P < .01). Based on the ROC curve analysis, both Δ%T/NTmax (area under the curve [AUC] = .772, P < .01) and Δ%SUVmax (AUC = .829, P < .01) predicted good histologic response. However, there was no significant difference between the AUCs of Δ%T/NTmax and Δ%SUVmax (P = .44). The sensitivity and specificity for predicting good histologic response were 83.3% and 75.0%, for the criterion Δ%T/NTmax <-12.5%, and 80.0% and 81.3% for the criterion Δ%SUVmax <-49.0%, respectively.The Tc-MDP bone scan and F-FDG PET scan are non-inferior to each other in predicting the histologic response of osteosarcoma treatments. The Tc-MDP bone scan and F-FDG PET scan showed respective advantages with differing features. Therefore, physicians should consider which scan is appropriate for their own institute based on the advantages of each scan and the circumstances of the institute.

According to the sentinel node biopsy (SNB), systematic pelvic lymph node dissection (PLND) may not be needed for patients with early-stage endometrial cancer. On the other hand, imaging technology including fluorodeoxyglucose-positron emission tomography/computed tomography (FDG PET/CT) has been developing worldwide. The aim of this study was to evaluate the combined diagnostic accuracy of FDG PET/CT and SNB in the prediction of pelvic lymph node metastasis in endometrial cancer patients.One hundred twenty-one patients with endometrial cancer underwent FDG PET/CT before hysterectomy and received SNB followed by systematic PLND. Univariate and multivariate analyses were performed to compare the diagnostic accuracy of FDG PET/CT and SNB in the prediction of pelvic node metastasis to the ultimate histologic status.FDG PET/CT had lower sensitivity (36.8% versus 57.9%, P = .1) and a higher specificity (96.4% versus 84.8%, P < .01) than SNB. The kappa statistics of FDG PET/CT and SNB were 0.37 (95% CI, 0.15-0.59) and 0.72 (95% CI, 0.53-0.90), respectively. The sensitivity of SNB was significantly higher than that of FDG PET/CT in all hemi-pelvises (HPs) in which the short axis of the largest metastatic lymph node was <5 mm in diameter (72.7% versus 18.2%, P = .01). In contrast, the sensitivity of FDG PET/CT was higher than that of SNB in all HPs in which the short axis of the largest metastatic lymph node was ≥5 mm in diameter (62.5% versus 37.5%, P = .2); however, the difference was not statistically significant. When the combined diagnosis of FDG PET/CT and SNB was made, the sensitivity and specificity were 84.2% and 82.1%, respectively.SNB was more useful for detecting lymph node metastasis than FDG PET/CT, especially in patients with small metastatic lymph nodes. The combined diagnosis of FDG PET/CT and SNB improves the sensitivity; PET-positive nodes should be dissected regardless of SNB status and HPs in which SNB was not detected should be dissected systematically regardless of FDG PET/CT status.

The aim of the present study was to evaluate the clinical significance of dual radiotracer studies, C-acetate and F-fluoro-D-glucose positron emission tomography/computed tomography (F-FDG PET/CT), for the prediction of response and recurrence after transarterial chemoembolization (TACE).This study retrospectively included a total 42 hepatoceullar carcinoma (HCC) patients (median age, 59; range, 34-85 years old) who underwent C-acetate and F-FDG PET/CT concurrently. Tumor uptake normalized by liver uptake (TNR; maximum tumor SUV to mean normal liver SUV ratio) was obtained first. Then, FAratio, which is the ratio of F-FDG TNR (TNR&#95;FDG) to C-acetate TNR, was obtained and correlated with response after TACE and recurrence-free survival (RFS), using a Cox multivariate proportional-hazard model.Among clinical factors, including the Hepatoma Arterial Embolization Prognostic score and positron emission tomography (PET) parameters, multiple regression analysis revealed FAratio and tumor size to be the only significant factors. As a PET parameter, FAratio exhibited the largest area under the curve in the prediction of response after TACE. In the Cox multivariate proportional-hazard model, TNR&#95;FDG was the only significant predictive factor for RFS. In subgroup analysis, TNR&#95;FDG was the only significant predictive factor for recurrence in intermediate stage patients. However, FAratio was the only significant predictive factor for recurrence in advanced stage patients.Dual radiotracer use of C-acetate and F-FDG PET/CT contributed to the prediction of response and recurrence after TACE. Used in addition to F-FDG, C-acetate PET/CT could give additional information in advanced stage patients. Based on the characteristics of tumor metabolism assessed by dual radiotracer PET/CT, treatment plans could be more personalized and optimized.

The aim of this study was to evaluate the diagnostic criteria of dual time point Fluorine-18 fluorodeoxyglucose (F-FDG) positron emission tomography/computed tomography (PET/CT) in differentiating malignant from benign focal hypermetabolic lesions of duodenum.A total of 50 patients underwent F-FDG PET/CT at 2 points: 60 ± 13.7 minutes (early imaging) and 120 ± 26.4 minutes (delayed imaging) after tracer injection. Early maximum standardized uptake value (SUVE), delayed maximum standardized uptake value (SUVD), difference between early and delayed maximum standardized uptake value (D-SUVmax), and retention index (RI) were calculated for each duodenal lesion. Receiver operating characteristic analysis (ROC) was performed to evaluate the discriminating validity of the parameters.There were 32 malignant and 18 benign focal F-FDG uptake duodenal lesions. The values of SUVE, SUVD, and D-SUVmax were significantly different between malignant and benign lesions (12.5 ± 6.3 vs 5.8 ± 1.2, 13.5 ± 6.5 vs 5.5 ± 1.1 and 0.3 ± 0.8 vs 1.0 ± 1.0, respectively). The areas under the curves (AUCs) of SUVE, SUVD, D-SUVmax were 0.932, 0.964 and 0.707, respectively. There was no significantly difference between SUVE and SUVD based on AUC. In detecting malignant lesions, SUVE=6.9 yielded a sensitivity of 88.9% and specificity of 84.4%, SUVD=7.2 yielded a sensitivity of 94.6% and specificity of 90.6%, D-SUVmax=0.5 yielded a sensitivity of 72.2% and specificity of 68.8%. SUVD was the best diagnostic indicator, regarding specificity and specificity.SUVE and SUVD had good sensitivity, specificity for differentiating duodenal lesions. But there was no significantly difference between diagnostic value of SUVE and SUVD. F-FDG uptake patterns are helpful for differentiating benign and malignant duodenal lesions.

Aim: To investigate the influence of scan time point and volume of intravenous contrast material in 18F-FDG PET/CT on maximum and mean standardized uptake values (SUV max / mean ) in bloodpool and liver., Methods: In 120 patients scheduled for routine whole-body 18F-FDG PET/CT the maximum and mean standardized uptake values (SUV max /SUV mean ) in the liver and blood pool were measured after varying scan time-point (delay 0 s-140 s post injectionem) and volume of contrast material (CM; 0 ml, 80 ml, 100 ml of 300 mg/ml of Iodine). Six groups of 20 patients were investigated: (1) without intravenous CM, (2-5) injection of 100 ml CM with a delay of 80 s (2), 100 s (3), 120 s (4), 140 s (5), and 80 ml CM and a delay of 100 s (6). SUV max , SUV mean , maximum Hounsfield units (HU max ) and average Hounsfield units (HU av ) were calculated with the use of manually drawn regions of interests (ROIs) over the aortic arch and healthy liver tissue., Results: SUV max in bloodpool was significantly higher in group 3, 4 and 6 compared to group 1. Groups 2 and 5 also showed higher mean values of SUV max , but the difference was not significant. SUV mean in bloodpool was also higher in groups 2, 3, 4, 5 and 6 compared to group 1, but the differences were only statistically significant in group 3. Both SUV max and SUV mean in healthy liver tissue did not show significant differences when compared to the non contrast-enhanced control group., Conclusion: SUV max and to a lesser extent SUV mean measured in CM enhanced FDG PET/CT in blood pool could be significantly altered in high contrast CT examinations. This should be kept in mind in PET/CT protocols and evaluation relying on SUV max and SUV mean , for example when used in the assessment of therapy response, especially in highly vascularized tumor lesions. ZIEL:: Das Ziel dieser Studie war den Einfluss von unterschiedlichen Messzeitpunkten und Volumina bei der Gabe von intravenösem Kontrastmittel in der 18F-FDG PET/CT auf SUV max und SUV mean im Blutpool und Lebergewebe zu untersuchen., Methoden: In 120 Patienten, geplant für eine Ganzkörper 18F-FDG -PET/CT, wurden die maximalen und durchschnittlichen standardisierten Aufnahmewerte (SUV max /SUV mean ) in der Leber und im Blutpool, jeweils nach unterschiedlichen Messzeitpunkten (Verzögerung 0 s-140 s post injectionem) und verschiedenen Volumina von Kontrastmittel (KM; 0 ml, 80 ml, 100 ml mit einer Konzentration von 300 mg/ml Jod) gemessen. Sechs Gruppen von je 20 Patienten wurden untersucht: (1) ohne intravenöses KM, (2-5) Injektion von 100 ml KM mit einer Verzögerung von 80 s (2), 100 s (3), 120 s (4), 140 s (5), und 80 ml KM mit einer Verzögerung von 100 s (6). Es wurden jeweils die SUV max , SUV mean , die maximalen and die durchschnittlichen Hounsfield Einheiten (HU av , HU max ) anhand manuell gezeichneter Bereiche von Interesse (ROIs) im Aortenbogen und im gesunden Lebergewebe berechnet., Ergebnisse: Die SUV max im Blutpool waren im Vergleich zur Gruppe 1 signifikant höher in Gruppe 3, 4 und 6. Die Gruppen 2 und 5 zeigten ebenfalls höhere Durchschnittswerte von SUV max , der Unterschied war jedoch nicht signifikant. Die SUV mean im Blutpool waren im Vergleich zur Gruppe 1 ebenfalls höher in den Gruppen 2, 3, 4, 5 und 6, allerdings waren die Unterschiede nur in Gruppe 3 statistisch signifikant. Im Lebergewebe zeigten sowohl SUV max , als auch SUV mean keine signifikanten Unterschiede im Vergleich zu der nativen Kontrollgruppe., Schlussfolgerungen: In der Kontrastmittel-gestützten FDG PET/CT können die SUV max und in geringerem Ausmaß auch SUV mean im Blutpool durch Hochkontrast-CT Untersuchungen signifikant beeinflusst werden. Dies sollte bei PET/CT Protokollen bzw. Auswertungen, die auf SUV max und SUV mean beruhen, berücksichtigt werden, zum Beispiel bei der Beurteilung des Therapieansprechens insbesondere bei stark vaskularisiertem Tumorgewebe., Competing Interests: Disclosure The authors report no conflicts of interest in this work., (Schattauer GmbH.)

Objectives/hypothesis: The aim of this study was to assess and compare the diagnostic accuracy of 18 fluorodesoxyglucose positron emission/computed tomography (FDG-PET/CT) and magnetic resonance imaging (MRI) to detect T1-T2 head and neck squamous cell carcinoma (HNSCC)., Study Design: Prospective case series., Methods: Thirty-five consecutive patients with histologically proven T1-T2 HNSCC were prospectively included. All patients underwent pretherapeutic FDG-PET/CT and MRI. Two nuclear medicine physicians and 2 radiologists blindly reviewed all FDG-PET/CT and MRI, respectively. A five-point qualitative scale was used to estimate tumor detection ability. Sensitivity of each modality was compared together using a McNemar test. Interobserver variability was assessed by kappa index (κ) of Cohen statistics. Maximal standardized uptake value (SUV MAX ), metabolic tumor volume (MTV) in FDG-PET/CT, and gadolinium enhancement (%GE) in MRI of each tumor were recorded and compared with T stage using a Mann-Whitney test. Tumor-to-normal tissue ratios in FDG-PET/CT and MRI (TNR PET and TNR MRI ) were calculated and compared together using a Student t test., Results: Among the 35 primary tumors, 29 were detected by FDG-PET/CT and 22 by MRI. MRI detected none of the six lesions incorrectly identified by FDG-PET/CT. FDG-PET/CT correctly identified seven of the 13 MRI false-negative results. Sensitivity of FDG-PET/CT to detect T1-T2 HNSCC was significantly higher than MRI (83% vs. 63%, P = .015). T stage was significantly correlated with MTV (P = .002) unlike with SUV MAX (P = .06) and %GE (P = .70). TNR PET was significantly higher than TNR MRI (3.5 ± 3.2 vs. 1.2 ± 0.3, P < .0001)., Conclusions: Our study showed a higher diagnostic accuracy of FDG-PET/CT than MRI to detect T1-T2 HNSCC with a good interobserver agreement., Level of Evidence: 4. Laryngoscope, 128:378-385, 2018., (© 2017 The American Laryngological, Rhinological and Otological Society, Inc.)

Introduction: Polymyalgia rheumatica (PMR) is an inflammatory disorder that affects the elderly. At present, evidence is limited regarding the usefulness of positron emission tomography-computed tomography (PET-CT) in the diagnosis of PMR. This study aimed to compare patient characteristics and symptoms with PET-CT findings in a Danish population of PMR patients without clinical symptoms of giant cell arteritis., Methods: The medical records of 50 Danish PET-CT-scanned patients with PMR were reviewed. Symptoms, characteristics and PET-CT findings were registered from the medical records., Results: Fluorodeoxyglucose (FDG) uptake was seen at the shoulders and/or hips of about 80%, and at the spinous processes of about 50% of the patients. Furthermore, 14% of the patients showed no FDG uptake at any of the studied locations. A sensitivity of 79% for PMR was found if there was FDG uptake at any two of the following three locations: the shoulder, the hip and the spinous processes. Vascular FDG uptake was seen in 7% of the patients. No significant correlations between any symptoms and any PET-CT findings were found. C-reactive protein level was significantly lower in patients receiving glucocorticoids, and completely normal scans were seen significantly more often in patients receiving steroid treatment., Conclusions: PET-CT is a sensitive imaging technique in PMR patients. Symptoms and PET-CT findings do not correlate in PMR. Steroid treatment prior to PET-CT reduces the scan's ability to demonstrate inflammation in PMR patients., Funding: none., Trial Registration: not relevant., (Articles published in the DMJ are “open access”. This means that the articles are distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits any non-commercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.)

We investigated the prognostic value of interim F-FDG PET/CT (PET-2) in pediatric Hodgkin lymphoma (pHL), evaluating both visual and semiquantitative analysis.Thirty pHL patients (age ≤16) underwent serial F-FDG PET/CT: at baseline (PET-0), after 2 cycles of chemotherapy (PET-2) and at the end of first-line chemotherapy (PET-T). PET response assessment was carried out visually according to the Deauville Score (DS), as well as semiquantitatively by using the semiquantitative parameters reduction from PET-0 to PET-2 (ΔΣSUVmax0-2, ΔΣSUVmean0-2). Final clinical response assessment (outcome) at the end of first-line chemotherapy was the criterion standard, considering patients as responders (R) or nonresponders (NR). Disease status was followed identifying patients with absence or relapsed/progression disease (mean follow-up: 24 months, range 3-78).Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of visual and semiquantitative assessment were calculated; furthermore, Fisher exact test was performed to evaluate the association between both visual and semiquantitative assessment and outcome at the end of the first-line chemotherapy. The prognostic capability of PET-2 semiquantitative parameters was calculated by ROC analysis and expressed as area under curve (AUC). Finally, progression-free survival (PFS) was analyzed according to PET-2 results based on the 5-point scale and semiquantitative criteria, using the Kaplan-Meier method.Based on the outcome at the end of first-line chemotherapy, 5 of 30 patients were NR, the remnant 25 of 30 were R. Sensitivity, specificity, PPV, NPV, and accuracy of visual analysis were 60%,72%,30%,90%,70%; conversely, sensitivity, specificity, PPV, NPV, and accuracy of semiquantitative assessment were 80%, 92%, 66.7%, 95.8%, 90%. The highest AUC resulted for ΔΣSUVmax0-2 (0.836; cut-off <12.5; sensitivity 80%; specificity 91%). The association between ΔΣSUVmax0-2 and outcome at the end of first-line chemotherapy resulted to have a strong statistical significance (P = 0.0026). Both methods demonstrated to influence PFS, even if the semiquantitative assessment allowed a more accurate identification of patients with a high risk of treatment failure (P = 0.005).Our preliminary results showed that PET-2 visual assessment, by using Deauville criteria, can be improved by using the semiquantitative analysis. The SUV max reduction (ΔΣSUVmax0-2) evaluation might provide a support for the interpretation of intermediate scores, predicting with good confidence those patients who will have a poor outcome and require alternative therapies., Competing Interests: The authors report no conflicts of interest.

To provide a systematic review of recently published reports and carry out a meta-analysis on the use of radiolabeled choline PET/computed tomography (CT) as a guide for salvage lymph node dissection (sLND) in prostate cancer patients with biochemical recurrence after primary treatments. Bibliographic database searches, from 2005 to May 2015, including Pubmed, Web of Science, and TripDatabase, were performed to find studies that included only patients who underwent sLND after radiolabeled choline PET/CT alone or in combination with other imaging modalities. For the qualitative assessment, all studies including the selected population were considered. Conversely, for the quantitative assessment, articles were included only if absolute numbers of true positive, true negative, false positive, and false negative test results were available or derivable from the text for lymph node metastases. Reviews, clinical reports, and editorial articles were excluded from analyses. Eighteen studies fulfilled the inclusion criteria and were assessed qualitatively. A total of 750 patients underwent radiolabeled choline (such as C-choline or F-choline) PET/CT before sLND. A quantitative evaluation was performed in nine studies. A patient-based, a lesion-based, and a site-based analysis was carried out in nine, four, and five studies, respectively. The pooled sensitivities were 85.3% [95% confidence interval (CI): 78.5-90.3%], 56.2% (95% CI: 41.6-69.7%), 75.3% (95% CI: 56.6-87.7%), and 63.7% (95% CI: 41-81.6%), respectively, for patient-based, lesion-based, pelvic site-based, and retroperitoneal site-based analysis. The pooled positive predictive values (PPVs) were 75% (95% CI: 68-80.9%), 85.8% (95% CI: 66.8-94.8%), 81.2% (95% CI: 70.1-88.9%), and 75.2% (95% CI: 58.7-86.7%), respectively, in the same analyses. High heterogeneities among the studies were found for sensitivities and PPVs ranging between 61.7-93.3% and 60.6-94.5%, respectively. Radiolabeled choline PET/CT has only a moderate sensitivity for the detection of metastatic lymph nodes in patients who are candidates for sLND, although the pooled PPVs ranged between 75 and 85.8% for all type of subanalyses. The presence of high heterogeneity among the studies should be considered carefully.

Background: To examine national imaging strategies regarding the use of F-18-FDG PET-CT in patients with Ewing sarcoma and study factors that might influence the use of PET-CT, such as tumour biology (Picci grade of operation specimen), clinical disease stage and age., Methods: We examined the medical records including pathology and imaging of all patients below 30 years diagnosed with Ewing sarcoma in Norway in 2005-2012., Results: Of 61 patients treated at one of the two national sarcoma treatment service centres (Oslo: 35, Bergen: 26), 29 patients had localized disease, 8 had tumour extending to organs nearby and 24 had metastases. Among 35 operated patients with neoadjuvant chemotherapy, 15 had Picci grades II and III (good responders) and 20 grade I (poor responders). We found a significant difference in the use of PET-CT (Oslo/Bergen 0·9 versus 2·0 scans per patient, P = 0·010) and in the use of MRI (Oslo/Bergen: eight versus 13, P = 0·006). No differences were proven for ultrasound, radiography, CT or skeletal scintigraphy. The number of PET-CTs was associated with clinical disease stage at diagnosis (P = 0·041) but not with Picci grade or age. The number of PET studies was not correlated to the number of MR studies., Conclusions: The use of PET-CT in children and young adults diagnosed with Ewing sarcoma in Norway during 2005-2012 at the two national sarcoma treatment service centres differed significantly. The use of PET-CT imaging was related to the clinical disease stage at diagnosis but unrelated to patient age and tumour biology (Picci grade)., (© 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.)

Background: The frequency and clinically important characteristics of incidental (18)F-fluorodeoxyglucose ([18 F]FDG) positron emission tomography (PET) uptake in the gastrointestinal tract (GIT) on PET/CT imaging in adults remain elusive., Methods: All PET/CT reports from 1/1/2000 to 12/31/2009 at a single tertiary referral center were reviewed; clinical information was obtained from cases with incidental (18)F-FDG uptake in the GIT, with follow-up through October, 2012., Results: Of the 41,538 PET/CT scans performed during the study period, 303 (0.7 %) had incidental GIT uptake. The most common indication for the PET/CT order was cancer staging (226 cases, 75 %), with 74 % for solid and 26 % for hematologic malignancies. Of those with solid malignancy, only 51 (17 %) had known metastatic disease. The most common site of GIT uptake was the colon, and of the 240 cases with colonic uptake, the most common areas of uptake were cecum (n = 65), sigmoid (n = 60), and ascending colon (n = 50). Investigations were pursued for the GIT uptake in 147 cases (49 %), whereas 51 % did not undergo additional studies, largely due to advanced disease. There were 73 premalignant colonic lesions diagnosed in 56 cases (tubular adenoma, n = 36; tubulovillous adenoma with low grade dysplasia, n = 27; sessile serrated adenoma, n = 4; tubulovillous adenoma with high grade dysplasia, n = 3; villous adenoma, n = 3), and 20 cases with newly diagnosed primary colon cancer. All 20 (100 %) patients with malignant colonic lesions had a focal pattern of [18 F]FDG uptake. Among cases with a known pattern of [18 F]FDG uptake, 98 % of those with premalignant lesions had focal [18 F]FDG uptake. Eighteen (90 %) of the cases with newly diagnosed colon cancer were not known to have metastatic disease of their primary tumor. Areas of incidental uptake in the ascending colon had the greatest chance (42 %) of being malignant and premalignant lesions than in any other area., Conclusion: Focality of uptake is highly sensitive for malignant and premalignant lesions of the GIT. In patients without metastatic disease, incidental focal [18]FDG uptake in the GIT on PET/CT imaging warrants further evaluation.

Objectives: Routine visual assessment of positron emission tomography (PET) for thoracic lymph node (LN) staging in patients with non-small cell lung cancer (NSCLC) is limited by a lack of reliable assessment criteria. This study evaluates the accuracy and inter-rater agreement of a standardized approach with unified windowing and a PET-based visual score., Materials and Methods: This retrospective analysis included pretherapeutic FDG-PET data of 86 patients with NSCLC. After standardized windowing (threshold: 2×liver SUVmean) the LN uptake was assessed visually by three independent readers with varying levels of experience using a 4-step score (1, LN uptake≤mediastinal blood pool structures (MBPS); 2, MBPS3). The inexperienced (n=1), advanced (n=1), and expert readers (n=1) achieved similar accuracies of 93.5%, 91.4% and 92.1%, respectively (P>0.05 each). Cohen's κ ranged from 0.92 to 0.96 and Fleiss' κ was 0.93. ROC-analyses showed no significant differences between attendant readers within any subgroup (AUC, 0.92-0.96)., Conclusion: Applying unified windowing, the introduced PET-score achieved highly accurate and robust LN assessment. This approach may shorten learning curves of inexperienced readers, facilitate multicenter trials, and improve comparability of future studies., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Unlabelled: Preclinical data suggest a negative correlation between brown adipose tissue (BAT) and the degree of coronary atherosclerosis. We sought to evaluate the relationship between (18)F-FDG uptake in supraclavicular BAT in relation to arterial inflammation and subsequent cardiovascular disease (CVD) events in humans., Methods: Individuals who underwent (18)F-FDG PET/CT for clinical indications but who did not have either cancer or known atherosclerotic disease at the time of imaging were included. A radiologist masked to clinical data measured (18)F-FDG uptake within BAT (in the supraclavicular region) as well as in subcutaneous adipose tissues. Tissue density was evaluated using CT (Hounsfield units). Arterial inflammation was assessed by measuring arterial (18)F-FDG uptake and calculating target-to-background ratio. CVD events were independently adjudicated by masked cardiologists. Thereafter, the relationship between BAT activity and CVD events was evaluated., Results: A total of 443 patients (age, 55 y [44-66 y]; 44% men; body mass index [BMI], 26 [range, 23-31]) were included, and 30 patients experienced a cardiovascular event during a median follow-up of 4 y. BAT activity negatively correlated with arterial inflammation (r = -0.178, P < 0.01), a relationship that persisted after correcting for age and BMI (r = -0.147, P < 0.01). When either high sensitivity or high accuracy thresholds (from receiver-operating curve analyses) were used to define elevated BAT, high BAT was associated with a reduced risk of CVD events (P = 0.048), even after correcting for age (P = 0.037)., Conclusion: Our results suggest that increased supraclavicular BAT activity is inversely associated with arterial inflammation, independently of age and BMI. Additionally, increased BAT may be associated with fewer cardiovascular events., (© 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.)

Unlabelled: The PET Response Criteria in Solid Tumors (PERCIST) are not specific regarding the number of lesions that should be analyzed per patient. This study evaluated how the number of analyzed lesions affects response assessment in metastatic breast cancer., Methods: In 60 patients, response was assessed by the change in SUVpeak, normalized to lean body mass, of the most (18)F-FDG-avid lesion (PERCIST 1) and by the change in the sum of normalized SUVpeak for up to 5 lesions (PERCIST 5). The correlation between response by PERCIST and progression-free and disease-specific survival was evaluated., Results: In responders and nonresponders, the respective progression-free survival at 2 y was 37.26% and 6.43% for PERCIST 1 (P < 0.0001) and 33.65% and 7.14% for PERCIST 5 (P < 0.0001) and the respective disease-specific survival at 4 y was 58.96% and 25.44% for PERCIST 1 (P < 0.012) and 59.12% vs 20.01% for PERCIST 5 (P < 0.002)., Conclusion: The number of analyzed lesions does not appear to have a major impact on the prognostic value of response assessment with (18)F-FDG PET/CT in metastatic breast cancer., (© 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.)