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Purpose: The need for an interval between the administration of long-acting Somatostatin Receptor Analogues (SSA) and the [68Ga]Ga-DOTA-TATE PET has been questioned based on recent literature in the new EANM guidelines. Here an earlier studies showed that SSA injection immediately before SSTR PET had minimal effect on normal organ and tumor uptake (1). However, data are scarce and there are (small) differences between [68Ga]Ga-DOTA-TATE and [68Ga]Ga-DOTA-TOC binding affinity, and it remains unknown whether these findings can be directly translated to scans with [68Ga]Ga-DOTA-TOC as well. The purpose of this study was to assess the effect of SSA use on the biodistribution in a subsequent [68Ga]Ga-DOTA-TOC PET/CT and compare this intra-individually across several cycles of SSA treatments. Methods: Retrospectively, 35 patients with NENs were included. [68Ga]Ga-DOTA-TOC PET at staging and after the 1st and 2nd cycle of SSA were included. SUVmean and SUVmax of blood, visceral organs, primary tumor and two metastases were determined. Also, the interval between SSA therapy and the PET scan was registered. Results: Treatment with SSA resulted in a significantly higher bloodpool activity and lower visceral tracer uptake. This effect was maintained after a 2nd cycle of SSA therapy. Furthermore, there was an inverse relationship between bloodpool tracer availability and visceral tracer binding and a positive correlation between bloodpool tracer availability and primary tumor tracer uptake. With an interval of up to 5 days, there was a significantly higher bloodpool activity than at longer intervals. Conclusion: Absolute comparison of the SUV on [68Ga]Ga-DOTA-TOC PET should be done with caution as the altered biodistribution of the tracer after SSA treatment should be taken into account. We recommend not to perform a scan within the first 5 days after the injection of lanreotide. [ABSTRACT FROM AUTHOR]

Aims Long QT syndrome (LQTS) is associated with malignant arrhythmias and sudden death from birth to advanced age. Prolongation of the QT-interval, may however be concealed on standard electrocardiograms (ECG). The brisk-standing-test (BST) was developed to guide LQTS-diagnosis and treatment in adults. We hypothesized that the BST may be used in prepubertal children to identify LQTS subjects. Accordingly, reference values for the BST should be available to prevent incorrect diagnosis and treatment of LQTS. In this study, we aim to present reference values for prepubertal children. Methods and results Healthy, prepubertal children, aged 7–13 years underwent a standard supine resting ECG and during continuous ECG recording performed a BST. The QT-interval and heart rate corrected QTc were measured during the different BST stages. Fifty-seven children, 29 boys (10.2 ± 1.1 years) and 28 girls (9.9 ± 1.1 years) were included. Baseline characteristics and response to standing were not statistically different for boys and girls: mean supine pre-standing heart rate 74 ± 9 vs. 77 ± 9 bpm, supine pre-standing QTc 406 ± 27 vs. 407 ± 17 ms, maximal heart rate upon standing 109 ± 11 vs. 112 ± 11 bpm, and QTc at maximal heart rate 484 ± 29 vs. 487 ± 35 ms. The QT interval corrected for heart rate-prolongation at maximal tachycardia after standing was 79 ± 26 (19–144) ms, which is significantly longer than previously published values in adults (50± 30 ms). Conclusions The QT interval corrected for heart rate prolongation after brisk standing in healthy prepubertal children is more pronounced than in healthy adults. This finding advocates distinct prepubertal cut-off values because using adult values for prepubertal children would yield false positive results with the risk of incorrect LQTS-diagnosis and overtreatment. [ABSTRACT FROM AUTHOR]

Aims: Long QT syndrome (LQTS) is associated with malignant arrhythmias and sudden death from birth to advanced age. Prolongation of the QT-interval, may however be concealed on standard electrocardiograms (ECG). The brisk-standing-test (BST) was developed to guide LQTS-diagnosis and treatment in adults. We hypothesized that the BST may be used in prepubertal children to identify LQTS subjects. Accordingly, reference values for the BST should be available to prevent incorrect diagnosis and treatment of LQTS. In this study, we aim to present reference values for prepubertal children.Methods and results: Healthy, prepubertal children, aged 7-13 years underwent a standard supine resting ECG and during continuous ECG recording performed a BST. The QT-interval and heart rate corrected QTc were measured during the different BST stages. Fifty-seven children, 29 boys (10.2 ± 1.1 years) and 28 girls (9.9 ± 1.1 years) were included. Baseline characteristics and response to standing were not statistically different for boys and girls: mean supine pre-standing heart rate 74 ± 9 vs. 77 ± 9 bpm, supine pre-standing QTc 406 ± 27 vs. 407 ± 17 ms, maximal heart rate upon standing 109 ± 11 vs. 112 ± 11 bpm, and QTc at maximal heart rate 484 ± 29 vs. 487 ± 35 ms. The QT interval corrected for heart rate-prolongation at maximal tachycardia after standing was 79 ± 26 (19-144) ms, which is significantly longer than previously published values in adults (50± 30 ms).Conclusions: The QT interval corrected for heart rate prolongation after brisk standing in healthy prepubertal children is more pronounced than in healthy adults. This finding advocates distinct prepubertal cut-off values because using adult values for prepubertal children would yield false positive results with the risk of incorrect LQTS-diagnosis and overtreatment. [ABSTRACT FROM AUTHOR]