Correlates of markers of dyssynchrony in patients with STEMI and multivessel disease: an analysis from the IAEA SPECT STEMI trial.

BACKGROUND: In this substudy of the Value of Gated-SPECT MPI for Ischemia- Guided PCI of non-culprit vessels in STEMI Patients with Multi vessel Disease after primary PCI trial on the value of myocardial perfusion imaging (MPI) for ischemia-guided percutaneous coronary intervention (PCI) of nonculprit vessels in patients with ST-segment-elevation myocardial infarction (STEMI) and multivessel disease after primary PCI we aim to assess if infarct size affects conventional measures of dyssynchrony at rest. Additionally, we explore if there is an independent correlation of stress-inducible ischemia with dyssynchrony at rest. METHODS: The 48 patients with imaging at randomization were analyzed. Gated-single-photon emission computed tomography (SPECT) MPI with vasodilator stress and technetium-99m-labeled tracers was performed. The phase histogram bandwidth (HBW), phase SD, and entropy were obtained with the QGS software. Correlation between dyssynchrony at rest and infarct size and inducible ischemia was performed using the Spearman test. RESULTS: According to normal database limits dyssynchrony parameters at rest were abnormal for men. In women only HBW was abnormal. Correlation between the summed rest score with dyssynchrony was significant only for entropy (P = 0.035). No correlation was observed for dyssynchrony and stress-induced ischemia. CONCLUSION: Entropy, as a measure of dyssynchrony, has potential in the assessment of patients with STEMI and multivessel disease after primary PCI. Smaller residual myocardial scars in PCI-reperfused patients with STEMI may contribute to the lack of correlation between dyssynchrony at rest and infarct size and stress-induced ischemia, respectively.

Posterior cingulate cortex hyperactivity in conversion disorder: a PET/MRI study.

Introduction: Several neuroimaging studies have been conducted to demonstrate the specific structural and functional brain correlations of conversion disorder. Although the findings of neuroimaging studies are not consistent, when evaluated as a whole, they suggest the presence of significant brain abnormalities. The aim of this study is to investigate brain metabolic activity through F-18 fluorodeoxyglucose PET/MRI in order to shed light on the neural correlates of conversion disorder. Methods: 20 patients diagnosed with conversion disorder were included in the study. Hamilton Depression and Anxiety Rating Scales, Somatosensory Amplification Scale and Somatoform Dissociation Scale were administered. Then, brain F-18 FDG-PET/MRI was performed.. Results: Hypermetabolism was found in posterior cingulate R, while glucose metabolisms of other brain regions were observed to be within the normal limits. When compared with the control group, statistically significant differences in z-scores were observed among all brain regions except for parietal superior R and cerebellum. No correlation was observed between the metabolisms of the left ACC and left medial PFC; left ACC and left temporal lateral cortex; cerebellum and left parietal inferior cortex despite the presence of positive correlations between these regions in the opposite hemisphere. Discussion: Results of the study suggest a potential involvement of the DMN which is associated with arousal and self-referential processing as well as regions associated with motor intention and self-agency.

A Rare Case of "Periportal Cuffing" as an Incidental Finding on 18F-FDG PET/CT.

A 7-year-old boy with known diagnosis of hereditary spherocytosis and ulcerative colitis was referred for 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography after detection of a 28 mm lesion suspicious for malignancy in spleen on upper abdomen magnetic resonance imaging (MRI). As an incidental finding, a moderately increased uptake of 18F-FDG was observed in periportal region with no definable mass. MRI revealed compatible findings with "periportal cuffing" as described on ultrasonography.

Clinical value of fluorine-18-fluorodeoxyglucose PET/MRI for liver metastasis in colorectal cancer: a prospective study.

PURPOSE: To evaluate the diagnostic performance of liver 18F-FDG PET/MRI in addition to whole-body PET/CT and to compare it with MRI in the detection and clinical management of liver metastasis in patients with colorectal cancer (CRC). MATERIAL AND METHODS: Seventy-eight patients with CRC who underwent whole-body 18F-FDG PET/CT followed by liver PET/MRI were prospectively included. Histopathological confirmation and/or at least 3 months of clinical follow-up after PET/MRI were accepted as gold standard. Lesion and patient-based analyses were performed to evaluate the diagnostics performances of PET/CT, PET/MRI and MRI. In addition, changes of clinical management were evaluated. RESULTS: On lesion-based analysis, for PET/CT, PET/MRI and MRI; sensitivity (Se): 55.6%, 97.2% and 100%; specificity (Sp): 98.5%, 100% and 80.5%; and accuracy (Acc): 70.7%, 98.2% and 93.1% were calculated, respectively. Se and Acc of PET/MRI and MRI were significantly superior than PET/CT (P < 0.001). Se and Acc of PET/MRI and MRI were comparable; however, Sp of PET/MRI was significantly better than MRI (P < 0.001). On patient-based analysis, Se: 75.6%, 100% and 100%; Sp: 97.3%, 100% and 86.5%; and Acc: 85.9%, 100% and 93.5% were calculated, respectively. Se and Acc of PET/MRI were significantly superior than PET/CT (P < 0.001). Also, Se of MRI was significantly superior than PET/CT (P < 0.001). Se of PET/MRI and MRI were comparable, but Sp and Acc of PET/MRI were significantly better than MRI. The additional information obtained from liver PET/MRI changed treatment strategy in 14/78 (18%) patients compared to PET/CT or alone liver MRI. CONCLUSION: Diagnostic performances of PET/MRI and MRI for detection of CRC liver metastasis is superior to PET/CT. PET/MRI especially helps in the accurate detection of liver metastases that are suspicious on MRI and has the potential to change the clinical management of especially oligometastatic patients by identifying uncertain liver lesions.

Ischemia-guided vs routine non-culprit vessel angioplasty for patients with ST segment elevation myocardial infarction and multi-vessel disease: the IAEA SPECT STEMI trial.

BACKGROUND: In patients with multi-vessel disease presenting with ST elevation myocardial infarction (STEMI), the efficacy and safety of ischemia-guided, vs routine non-culprit vessel angioplasty has not been adequately studied. METHODS: We conducted an international, randomized, non-inferiority trial comparing ischemia-guided non-culprit vessel angioplasty to routine non-culprit vessel angioplasty, following primary PCI for STEMI. The primary outcome was the between-group difference in percent ischemic myocardium at follow-up stress MPI. All MPI images were processed and analyzed at a central core lab, blinded to treatment allocation. RESULTS: In all, 109 patients were enrolled from nine countries. In the ischemia-guided arm, 25/48 (47%) patients underwent non-culprit vessel PCI following stress MPI. In the routine non-culprit PCI arm, 43/56 (77%) patients underwent angioplasty (86% within 6 weeks of randomization). The median percentage of ischemic myocardium on follow-up imaging (mean 16.5 months) was low, and identical (2.9%) in both arms (difference 0.13%, 95%CI - 1.3%-1.6%, P < .0001; non-inferiority margin 5%). CONCLUSION: A strategy of ischemia-guided non-culprit PCI resulted in low ischemia burden, and was non-inferior to a strategy of routine non-culprit vessel PCI in reducing ischemia burden. Selective non-culprit PCI following STEMI offers the potential for cost-savings, and may be particularly relevant to low-resource settings. (CTRI/2018/08/015384).

Can Serum Thyroglobulin Levels Help to Identify the Involved Neck Compartment of Differentiated Thyroid Carcinoma?

We aimed to evaluate the predictive ability of serum thyroglobulin (Tg) levels on the localization of the metastatic lymph node compartments in locoregional metastases of papillary thyroid cancer (PTC). This retrospective study included 143 patients who underwent neck dissections for a total of 172 for persistent/recurrent locoregional PTC. They were grouped according to the localization of lymph node metastasis (LNM): Central (C-LNM), Lateral (L-LNM), both central and lateral LNM (C+L LNM). To confirm that the Tg cutoff discriminated LNM localizations, the sample was categorized as suppressed (<0.1 mU/l) or non-suppressed (>0.1 mU/l) according to TSH and ROC analysis. Mixed-effects models were used to investigate the effect of LNM localization on Tg levels and to eliminate the confounding effects of TSH, tumor burden (defined as the number and the largest diameter of LNM), and RAI. Mean Tg levels were 1.43 µg/l for C-LNM (n=47), 3.7 µg/l for L-LNM (n=99), and 8.60 µg/l for C+L LNM (n=26). Independent of TSH, tumor burden and RAI, the mean Tg levels of L-LNM and C+L LNM groups were not significantly different, while that of C-LNM was significantly lower than those of L-LNM and C+L LNM. To discriminate C-LNM from L-LNM and C+L LNM in patients with TSH>0.1 mU/l, the optimal cutoff for Tg was 1.05 µg/l (sensitivity=74.7%, specificity=70.4%, PPV=87.7%). L-LNM increases serum Tg levels more than C-LNM in persistent/recurrent locoregional nodal disease of PTC. Tg above 1.05 µg/l may indicate lateral LNM. Tg may be an important marker for the localization of LNM in the neck.

A Rare Pitfall in Bone Mineral Densitometry: Gaucher Disease.

ABSTRACT: We report a rare case of type 3 Gaucher disease presenting with calcified mesenteric lymph nodes that interfere with bone mineral densitometric measurements.

Elevated Angiogenic Factor Levels After Transarterial Radioembolization for Colorectal Cancer Liver Metastases May Predict a Poor Prognosis.

Objectives: To analyze the change in circulating angiogenic factor levels after transarterial radioembolization (TARE) for colorectal cancer liver metastases (CRCLMs) and its prognostic significance. Methods: Blood samples immediately before TARE and on 1 day, 1 week and 6 weeks after were collected for angiogenic factor analysis in 23 patients. Results: Patients with elevated serum basic fibroblast growth factor and platelet-derived growth factor levels in the 1st week and vascular endothelial growth factor (VEGF) levels in the 6th week after TARE had significantly shorter median overall survival (OS) times. Conclusion: Some early increases in serum angiogenic factor levels and in serum VEGF in the 6th week after TARE for CRCLMs are related to short OS and progression-free survival.

Combined clinical and specific positron emission tomography/computed tomography-based radiomic features and machine-learning model in prediction of thymoma risk groups.

OBJECTIVES: In this single-center study, we aimed to propose a machine-learning model and assess its ability with clinical data to classify low- and high-risk thymoma on fluorine-18 (18F) fluorodeoxyglucose (FDG) (18F-FDG) PET/computed tomography (CT) images. METHODS: Twenty-seven patients (14 male, 13 female; mean age: 49.6 ± 10.2 years) who underwent PET/CT to evaluate the suspected anterior mediastinal mass and histopathologically diagnosed with thymoma were included. On 18F-FDG PET/CT images, the anterior mediastinal tumor was segmented. Standardized uptake value (SUV)max, SUVmean, SUVpeak, MTV and total lesion glycolysis of primary mediastinal lesions were calculated. For texture analysis first, second, and higher-order texture features were calculated. Clinical information includes gender, age, myasthenia gravis status; serum levels of lactate dehydrogenase (LDH), alkaline phosphatase, C-reactive protein, hemoglobin, white blood cell, lymphocyte and platelet counts were included in the analysis. RESULTS: Histopathologic examination was consistent with low risk and high-risk thymoma in 15 cases and 12 cases, respectively. The age and myasthenic syndrome were statistically significant in both groups (P = 0.039 and P = 0.05, respectively). The serum LDH level was also statistically significant in both groups (450.86 ± 487.07 vs. 204.82 ± 59.04; P < 0.001). The highest AUC has been achieved with MLP Classifier (ANN) machine learning method, with a range of 0.830 then the other learning classifiers. Three features were identified to differentiate low- and high-risk thymoma for the machine learning, namely; myasthenia gravis, LDH, SHAPE_Sphericity [only for 3D ROI (nz>1)]. CONCLUSIONS: This small dataset study has proposed a machine-learning model by MLP Classifier (ANN) analysis on 18F-FDG PET/CT images, which can predict low risk and high-risk thymoma. This study also demonstrated that the combination of clinical data and specific PET/CT-based radiomic features with image variables can predict thymoma risk groups. However, these results should be supported by studies with larger dataset.

Can Radiomics Analyses in 18F-FDG PET/CT Images of Primary Breast Carcinoma Predict Hormone Receptor Status?

OBJECTIVES: This study aimed to investigate the role of preoperative 18fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) radiomics features and metabolic parameters of primary breast tumors in predicting hormone receptor (HR) positivity. METHODS: A total of 153 patients with breast carcinoma who underwent preoperative 18F-FDG PET/CT were included. All PET/CT images were retrospectively reevaluated. Radiomics features of primary breast lesions reflecting tumor heterogeneity as well as standardized uptake value (SUV) metrics (SUVmin, SUVmean, SUVmax, and SUVpeak) and volumetric parameters such as metabolic tumor volume and total lesion glycolysis (TLG) were extracted by commercial texture analysis software package (LIFEx; https://www.lifexsoft.org/ index.php). WEKA and SPSS were used for statistical analysis. Binary logistic regression analysis was used to determine texture features predicting HR positivity. Accuracy, F-measure, precision, recall, and precision-recall curve area were used as data-mining performance criteria of texture features to predict HR positivity. RESULTS: None of the radiomics parameters were significant in predicting HR status. Only SUV metrics and TLG were statistically important. Mean ± standard deviations for SUVmean, SUVmax, and SUVpeak for the HR-negative group were significantly higher than those in the HR-positive group (6.73±4.36 vs. 5.20±3.32, p=0.027; 11.55±7.42 vs. 8.63±5.23, p=0.006; and 8.37±6.81 vs. 5.72±4.86; p=0.012). Cut-off values of SUVmean, SUVmax, and SUVpeak for the prediction of HR positivity were 4.93, 8.35, and 6.02, respectively. Among data-mining methods, logistic regression showed the best performance with accuracy of 0.762. CONCLUSION: In addition to the relatively limited number of patients in this study, radiomics parameters cannot predict the HR status of primary breast cancer. SUV levels of the HR-negative group were significantly higher than those of the HR-positive group. To clarify the role of metabolic and radiomics parameters in predicting HR status in breast cancer, further studies involving a larger study population are needed.

Myocardial perfusion SPECT findings in postCOVID period.

PURPOSE: To investigate if (i) the risk of ischemia on myocardial perfusion scan (MPS), (ii) number of coronary angiographies (CAG) performed, and (iii) necessity for invasive (stent implantation or coronary artery bypass grafting (CABG)) or medical treatment increased in patients infected with COVID-19. METHODS: Patients who were referred to MPS between August 2020 and April 2021 with a history of active symptomatic COVID-19 infection (confirmed by PCR positivity) in the last 6 months were involved in the study group. Age-and gender-matched control group was composed of randomly chosen patients who attended for MPS between January 2019 and September 2019, before pandemic. Frequency of ischemia, CAG, and invasive or medical treatments were compared between groups. RESULTS: Ischemia was reported more frequently in the study group (p < 0.001). In clinical evaluation, regardless of the MPS results, the necessity for invasive evaluation with CAG and treatment (either medical therapy or invasive interventions) was higher in the study group (p = 0.006 and p = 0.015). It was also true for patients with abnormal MPS results (p = 0.008 and p = 0.024) but not for the patients with ischemia (p = 0.29 and p = 0.06). CONCLUSION: There exists a significant increase in the frequency of ischemia on MPS, undergoing CAG, stent implantation or CABG, and initiation of medical therapy in patients with a history of COVID-19 infection in the last 6 months. MPS is a reliable method in patients who present with cardiovascular symptoms in the late COVID period.

Prognostic value of metabolic parameters on baseline 18F-FDG PET/CT in small cell lung cancer.

BACKGROUND: Maximum standardized uptake value (SUVmax) is the primary quantitave parameter given in 18F-FDG PET/CT reports. Calculations derived from three dimensional metabolic volumetric images have been proposed to be more successful than SUVmax alone in prognostification with a lower interobserver variability in many cancers. We aimed to determine the prognostic value of metabolic parameters derived from 18F-FDG PET/CT studies in small cell lung cancer (SCLC) patient population with a long follow-up time. METHODS: In this study, 38 consecutive SCLC patients (34M, 4F, age:65.76 ±8.18 years) who were referred to 18F-FDG PET/CT for staging between October 2006-January 2011 were included. SUVmax, SUVmean, SUVpeak, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were calculated. Overall survival (OS) was calculated from the date of the initial PET/CT to death from any cause. Survival tables were obtained and Kaplan Meier curves were reconstructed. Mantel-Cox regression analysis was performed in order to investigate if any of these parameters have an effect on survival along with other clinical risk factors. RESULTS: Median SUVmax, SUVmean, SUVpeak, MTV, TLG and LDH values were calculated as 13.9 g/dL, 6.4 g/dL,10.69 g/dL, 147 cm3, 1898.52 and 375U/L respectively. Median follow-up was 761.23±873.21 days (25.37 months, range:110-3338 days). Since basal 18F-FDG PET/CT scans, all patients were lost in the follow-up except for two patients. MTV was a significant prognostic factor in SCLC patients. Estimated mean survival times were 261.0±45.6 (95% CI: 171.6-350.3) days in patients with MTV value above the calculated median 147, and 577.0±124.0 (95% CI: 333.7-820.2) days in patients with MTV<147. The difference was statistically significant with a P=0.037. CONCLUSIONS: Baseline whole body MTV reflecting total tumor load is a prognostic index in SCLC. SUV is insufficient to predict prognosis.

Negative Histopathological Prognostic Factors Affecting Morbidity in T1 Differentiated Thyroid Carcinoma.

Background: The aim was to evaluate: (i) if multifocality is a negative prognostic factor; and (ii) the association of diameter of the largest tumor, total tumor diameter, and the ratio of the largest tumor diameter to total tumor diameter (DR) with histopathological and clinical outcome parameters in T1 differentiated thyroid carcinoma (DTC). Materials and Methods: In 1014 T1N0/1Mx patients, correlation between multifocality, contralateral lobe involvement, capsular-vascular invasion, diameter of the largest tumor, total tumor diameter, DR, and follow-up results were investigated. Results: Persistent/recurrent disease and necessity for additional radioiodine treatment (RAIT) were more frequent in cases with multifocality and contralateral lobe involvement (p = 0.035, p = 0.015, p = 0.021, and p = 0.04). Persistence/recurrence, reoperation in the neck, and additional RAIT were more frequent in patients with the size of the largest tumor focus >1 cm (p = 0.024, p < 0.001, and p = 0.002) and N1 status (p < 0.001, p < 0.001, and p < 0.001). Mean total tumor diameter was higher in patients with capsular invasion, contralateral lobe, and lymph node involvement (p = 0.001, p = 0.003, and p = 0.013). Conclusion: Multifocality, contralateral lobe involvement, diameter of the largest tumor >1 cm, and N1 status are related with increased risk of disease persistence, recurrence, reoperation, and additional RAIT. Sum of diameter of all tumor foci are associated with capsular invasion.

The prognostic value of 18F-fluorodeoxyglucose positron emission tomography/ computed tomography parameters in patients with malignant pleural mesothelioma.

BACKGROUND: In this study, we aimed to investigate the prognostic value of metabolic 18F-fluorodeoxyglucose positron emission tomography/computed tomography parameters in malignant pleural mesothelioma patients. METHODS: A total of 65 patients with malignant pleural mesothelioma (34 males, 31 females; median age: 60 years; range, 39 to 84 years) who underwent whole-body 18F-fluorodeoxyglucose positron emission tomography/computed tomography for staging before treatment between March 2008 and January 2018 were included. Relationships between clinicopathological factors and 18F-fluorodeoxyglucose positron emission tomography/computed tomography parameters and overall survival were evaluated using a log-rank test and Cox regression analysis. RESULTS: The median follow-up was 13 (range, 4 to 55) months. The Kaplan-Meier analysis revealed a mean survival time of 17±2.6 months. The cumulative two- and five-year survival rates were 34.8% and 7.8%, respectively. Univariate analysis showed that ≥60 age, left hemithorax involvement, a maximum standardized uptake value of ≥9.8, c-T4 status, c-M1 status, and non-surgery were negatively associated with overall survival (p<0.05). Multivariate analysis showed that ≥60 age, left hemithorax involvement, a maximum standardized uptake value of ≥9.8, c-M1 status, and a total lesion glycolysis of ≥180.2 g were negatively associated with overall survival (p<0.05). CONCLUSION: Metabolic parameters of 18F-fluorodeoxyglucose positron emission tomography/computed tomography have the potential to provide prognostic information for malignant pleural mesothelioma patients who are receiving surgery and/or chemotherapy.

Prognostic importance of prostatic specific antigen response in patients who received Lutetium-177 prostate-specific membrane antigen treatment for castration resistant prostate cancer.

BACKGROUND: This study aims to analyze the prognostic importance of serum prostate specific antigen (PSA) response in patients who received radioligand therapy (RLT) with Lu-177 Prostate-specific membrane antigen (PSMA) for their castration-resistant prostate cancer. METHODS: Thirty consecutive patients who received Lu-177 PSMA treatment for their castration-resistant prostate carcinoma were included. All the patients had undergone Ga-68 PSMA PET/CT scanning before Lu-177 PSMA therapy, which revealed multiple metastases. Patients were treated with a fixed dose (180 mCi) of Lu-177 PSMA at six to eight weeks intervals. PSA response was evaluated using Prostate Cancer Working Group 3 (PCWG3) criteria. Serum PSA response was classified as PSA progression (25% increase over the baseline and an increase in the absolute-value PSA level by at least 5 ng per millilitre), any <50% decline or ≥50% decline. PSA response was evaluated six weeks after every cycle. Response evaluation with radiological imaging and Ga-68 PSMA PET/CT were performed before the first cycle and eight weeks after the last cycle. RESULTS: Thirty patients were treated with a total of 171 cycles (median 4, range 3-7) of Lu-177 PSMA. A decline in serum PSA of ≥50% was detected in ten patients (33%) while a decline in PSA of any amount was observed in fifteen (50%) patients after the first cycle. After the last cycle, a decline in PSA ≥50% and of any amount was seen in thirteen (43%) and fourteen (46%) patients, respectively. Of the fifteen patients who were not responder after the first cycle, three (20%) had a decline in PSA of any amount after the completion of the RLT. Moreover, of the 20 patients who did not have a ≥50% decline in PSA level after the first cycle, four (20%) became responder after the last cycle. Regarding serum PSA response after the first cycle, median OS was significantly higher for patients who had ≥50% decline in PSA level with 21.0±10.0 (95% CI: 1.2-40.7) months compared to patients who had not with 8.0±2.6 (95% CI: 2.7-13.2) months (P=0.012). A decline in PSA of any amount after the first cycle did not have a significant impact on median OS (12.0±1.1 vs. 6.0±2.5 months, P=0.08). The decline in serum PSA level after the last cycle of treatment had a significant impact on OS. Median OS for the decline in PSA of any amount was calculated as 13.0±1.0 (95% CI: 10.9-15.0) months for responders and 6.0±1.9 (95% CI: 2.2-9.7) months for non-responders (P=0.016). Considering ≥50% of decline as a response, median OS was 21.0±5.8 (95% CI: 9.5-32.4) months for responders and 6.0±3.0 (95% CI: 0.1-11.8) months for non-responders (P=0.026). CONCLUSIONS: Serum PSA level during RLT with Lu-177 PSMA remains a clinically significant factor to predict OS times. About twenty percent of patients who were not responder after the first cycle could become responder after the last cycle. However, patients without PSA response after completion of all cycles should be closely followed-up. Non-responder patients can achieve a response with further treatments.

Role of Thyroglobulin Doubling Time in Differentiated Thyroid Cancer and Its Relationship with Demographic-Histopathologic Risk Factors and 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Parameters.

Background: Aim of this study was to investigate the relationship between thyroglobulin doubling time (TgDT) and basal risk factors and metabolic parameters derived from 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in differentiated thyroid cancer (DTC). Materials and Methods: An analysis of 95 DTC patients who had rising serum thyroglobulin (Tg) levels under levothyroxine (LT4) suppression after radioiodine therapy was made. TgDT was calculated for 28/95 patients. The relationship between TgDT and basal demographic and histopathologic risk factors, preablative Tg, and antithyroglobulin antibody (ATg) levels and metabolic parameters was analyzed. Results: In 28 patients (15M, 13F, mean age: 52.6 ± 17.6) that TgDT could be calculated, 18F-FDG PET/CT was positive in 12 patients. Median TgDT was lower in 18F-FDG PET/CT positive patients compared to the negative cases (p < 0.05). Patients with skeletal metastasis or local recurrence had a shorter DT compared to the patients with lung metastasis. TgDT was correlated with peak standardized uptake value (SUVpeak) (p < 0.05). Maximum standardized uptake value (SUVmax) was correlated with tumor size (p < 0.05) and mean standardized uptake value (SUVmean) with tumor size and vascular invasion (p < 0.05). Median SUVmax and SUVmean were higher in follicular cancer or poor histological variants of papillary DTC compared to papillary cancer classical variant patients Conclusion: TgDT may be predictive of a positive 18F-FDG PET/CT in DTC. Skeletal metastasis and local recurrence are related to shorter TgDT. Greater tumor size, vascular invasion, and follicular cancer or poor variants of papillary carcinoma are related with higher SUVmax and SUVmean. Larger scale studies are needed to confirm results and to calculate a possible cutoff of TgDT for a positive 18F-FDG PET/CT study.

Incidental 18F-Fluorocholine Uptake in an Esophageal Diverticulum: 18F-FCH in an Esophageal Diverticulum.

F-fluorocholine has recently emerged as a very sensitive agent for seeking parathyroid adenomas. We represent a case with esophageal diverticulum incidentally detected on F-fuorocholine PET/CT, which should be kept in mind as a reason of false positivity in primary hyperparathyroidism.