BackgroundSarcoidosis–lymphoma syndrome (SLS) is a rare disease in which both entities coexist. We aimed to study the role of 18F-fluorodeoxyglucose (FDG) and L–[3-18F] α-methyltyrosine (FAMT) positron emission tomography (PET)/computed tomography (CT) in differentiating between these two lesions.Case presentationA 54-year-old female with large liver tumors was referred to our Nuclear Medicine Department for staging using FDG PET/CT. She had a history of primary biliary cirrhosis (PBC) for 15 years and developed lung and mediastinal sarcoidosis 1 year before the liver tumors were noted. Abdominal dynamic CT revealed two well-circumscribed, peripherally-enhancing, low-density masses in the right lobe of the liver with intensive ring-form FDG uptakes at maximum standard uptake values (SUVmax) of 18.3 and 19.5, respectively. In the arterial phase, a hepatic artery was seen penetrating the tumor, a phenomenon known as “angiogram sign”. Chest PET/CT findings showed irregular thickening of the bronchovascular bundles, central peribronchial shaggy consolidations in the right middle and lower lobes (SUVmax, 4.6), and mediastinal and hilar lymphadenopathies (SUVmax, 2.7).After assessment, chemotherapy with rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate, and prednisone (R–CHOP) was administered for eight cycles. Follow-up imaging studies using FDG and FAMT PET/CT were performed 3 months after the last cycle of chemotherapy, which showed that the two highly FDG-avid tumors in the liver had disappeared. However, faint FDG uptake persisted in the lung consolidations (SUVmax, 6.3), and FDG uptake for the mediastinal lymphadenopathies increased (SUVmax of 5.8). In contrast, there was no significant uptake of FAMT in the liver, as well as in the lungs and the bilateral mediastinal lymphadenopathies. These discrepant uptakes between FDG and FAMT were compatible with sarcoidosis.ConclusionCombination of FDG and FAMT in PET/CT studies may play an important role in the management of SLS patients, especially in differentiating between sarcoidosis and lymphoma lesions.

No abstract

BackgroundThis meta-analysis aims to compare the diagnostic performance of l-3-18F-α-methyl tyrosine (18F-FAMT) positron emission tomography (PET) and 2-deoxy-2-[18F]fluoro-d-glucose (18F-FDG) PET for malignancy detection.MethodsThe workflow of this study follows Cochrane Collaboration Guidelines of a systematic review of diagnostic test accuracy studies. An electronic search was performed for clinical diagnostic studies directly comparing 18F-FAMT and 18F-FDG PET for malignant tumors. Study quality, the risks of bias and sources of variation among studies were assessed using the QUADAS (Quality Assessment of Diagnostic Accuracy Studies) assessment tool. A separate meta-analysis was performed for diagnostic performance based on visual assessment and diagnostic cut-off values. Whenever possible, a bivariate random-effect model was used for analysis and pooling of diagnostic measures across studies.ResultsElectronic search revealed 56 peer-reviewed basic science investigations and clinical studies. Six eligible studies (272 patients) of various type of cancer were meta-analyzed. The 18F-FAMT diagnostic accuracy for malignancy was higher than 18F-FDG based on both visual assessment (diagnostic odd ratio (DOR): 8.90, 95% confidence interval (CI) [2.4, 32.5]) vs 4.63, 95% CI [1.8, 12.2], area under curve (AUC): 77.4% vs 72.8%) and diagnostic cut-off (DOR: 13.83, 95% CI [6.3, 30.6] vs 7.85, 95% CI [3.7, 16.8], AUC: 85.6% vs 80.2%), respectively. While the average sensitivity and specificity of 18F-FAMT and 18F-FDG based on visual assessment were similar, 18F-FAMT was significantly more specific than 18F-FDG (p < 0.05) based on diagnostic cut-off values.Conclusions 18F-FAMT is more specific for malignancy than 18F-FDG, while their sensitivity is comparable. 18F-FAMT PET is equal to 18F-FDG PET in diagnostic performance for malignancy detection in several cancer types.

Background Internet gaming disorder has been a controversial topic for nearly a decade. Although internet addiction has been studied in medical students, there is a paucity of evidence regarding internet gaming disorder. Previous studies in Indonesia explored only the prevalence rate and characteristics. Objective This study aimed to determine the prevalence rate of internet gaming disorder and correlations between internet gaming disorder, temperament, and psychopathology among Indonesian medical students. Methods A cross-sectional study was performed from August 2019 to September 2019 using total and convenience sampling at a private university and a public university, respectively. The study variables were measured using the Indonesian version of the 10-item Internet Gaming Disorder Test, the Temperament and Character Inventory, and the Symptoms Checklist 90. Chi-square and logistic regression analyses were conducted to examine the relationships between demographic factors, temperament, psychopathology, and the presence of internet gaming disorder. Results Among the 639 respondents, the prevalence rate of internet gaming disorder was 2.03% (n=13), with a mean age of 20.23 (SD 0.13) years and an average gaming duration of 19.0 (SD 0.96) hours/week. Up to 71.2% respondents played using their mobile phones, and respondents with internet gaming disorder reported experiencing all psychopathologies assessed, except phobic anxiety. Bivariate analysis demonstrated that internet gaming disorder was associated with gender, gaming duration, gaming community affiliation, and 9 out of 10 domains of psychopathology. In a logistic regression model, internet gaming disorder was correlated with weekly gaming hours ≥20 hours (odds ratio [OR] 4.21, 95% CI 1.08-16.38, P=.04). Conclusions These findings suggest that the prevalence of internet gaming disorder among medical students in Jakarta, Indonesia is similar to that in other populations of Asian countries. The predisposing factor for internet gaming disorder was weekly gaming duration, while other demographic, temperament, and psychopathology variables acted as probable moderators. Strategies should, therefore, be developed and integrated into medical curriculum to screen and aid individuals with these predisposing factors.

The overexpression of vascular endothelial growth factor (VEGF) in varying types of solid tumor renders radioimmunotherapy (RIT) with the anti-VEGF antibody bevacizumab (BV) a promising treatment. However, the slow blood clearance of BV, which may increase the occurrence risk of hematotoxicity, hinders the application of BV-RIT. Using the avidin chase is a long-known blood clearance enhancement strategy for biotinylated-mAb. To enhance RIT efficacy by increasing the radioactivity dose, we evaluated the ability of avidin to accelerate the blood clearance of yttrium-90 (Y)-labeled biotinylated BV (Y-Bt-BV) in a xenograft mouse model of triple-negative breast cancer (TNBC). The biodistribution study in the TNBC xenograft mice confirmed the high and specific tumor accumulation of the indium-111 (In)-BV. The blood clearance enhancement effect of the avidin chase was demonstrated in the normal mouse studies with In-Bt-BV. In the subsequent biodistribution studies with the tumor-bearing mice, an optimized dose of avidin injection subsequent toIn-Bt-BV with an appropriate biotin valency successfully accelerated the blood clearance of In-Bt-BV without impairing its tumor accumulation level. The avidin chase enabled an increase in the maximum tolerated dose ofY-Bt-BV to twice as much as that of Y-BV in tumor-bearing mice and thereby significantly improved the therapeutic effect ofY-Bt-BV compared to Y-BV ( p< 0.05). These results underscored the potential usefulness of Y-bevacizumab-RIT with the avidin chase for the treatment of VEGF-positive tumors.

Background Pretargeting radioimmunotherapy (PRIT) is a promising approach that can reduce long-time retention of blood radioactivity and consequently reduce hematotoxicity. Among the PRIT strategies, the combination of biotin-conjugated mAb and radiolabeled streptavidin (StAv) is a simple and convenient method because of ease of preparation. This study performed three-step (3-step) PRIT using the sequential injection of (1) biotinylated bevacizumab (Bt-BV), (2) avidin, and (3) radiolabeled StAv for the treatment of triple-negative breast cancer (TNBC).Methods Four biodistribution studies were performed using 111 In in tumor-bearing mice to optimize each step of our PRIT methods. Further, a therapeutic study was performed with optimized 3-step PRIT using 90 Y-labeled StAv.Results Based on the biodistribution studies, the protein dose of Bt-BV and avidin was optimized to 100 μg and 10 molar equivalent of BV, respectively. Succinylation of StAv signi cantly decreased the kidney accumulation level (with succinylation (6.96 ± 0.91) vs without succinylation (20.60 ± 1.47) at 1 h after injection, p < 0.0001) with little effect on tumor accumulation level. In the therapeutic study, tumor growth was signi cantly suppressed in treatment groups with optimized 3-step PRIT using 90 Y-labeled succinylated StAv compared to that of the no-treatment group (p < 0.05). ConclusionThe 3-step PRIT strategy of this study achieved fast blood clearance and low kidney uptake with little effect on tumor accumulation level, and a certain level of therapeutic effect was consequently observed. These results indicated that the pretargeting treatment of the current study may be effective for human TNBC treatment.

Background: The F-18 fluorodeoxyglucose positron emission/computed tomography (FDG PET/CT) has become an established diagnostic imaging for malignancy. However, there are other diseases that can also be identified with FDG, some of them are infections such as tuberculosis. Case presentation: In this case report, two patients showed multiple hypermetabolic tuberculosis lesions on FDG PET/CT, with one of the patients having history of malignancy. The objective of the present case report is to emphasize the need to use other differential diagnosis techniques for tuberculosis especially in tuberculosisendemic countries when interpreting FDG PET/CT. Conclusion: By analyzing diagnostic imaging alone, there is a high chance of misinterpreting asymptomatic tuberculosis patient as having malignancy. Therefore, there is need for correlation with clinical data as well as other imaging modalities and PET/CT with more specific tracer in order to differentiate malignancy from benign disease such as tuberculosis.

No abstract