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Background: The evaluation of myocardial ischemia in patients with aortic valve stenosis (AS) with concomitant coronary artery disease (CAD) and possible microvascular dysfunction (MVD) is challenging because fractional flow reserve (FFR) and the resting full-cycle ratio (RFR) have not been validated in this clinical setting., Objectives: The objectives of this study in patients with AS and CAD were: 1) to describe the relationship between hyperemic and resting indexes; 2) to investigate the acute and long-term effects of aortic valve replacement (AVR) on epicardial indexes and microvascular function; 3) to assess the impact of these changes on clinical decision making; and 4) to determine FFR/RFR ischemia cutoff points in AS., Methods: In this prospective multicentric study, we performed serial measurements of FFR and RFR and evaluated MVD by means of coronary flow reserve, the index of microvascular resistance, and microvascular resistance reserve in patients with severe AS and intermediate to severe CAD before and 6 months after AVR. Patients underwent myocardial perfusion single-photon emission computed tomography before AVR., Results: In total, 146 coronary lesions in 116 patients were included. Before AVR, we observed high FFR/RFR discordance according to standard cutoff values (FFR negative [>0.80]/RFR positive [≤0.89] in 42.3% [68/137] of these lesions). Acutely after AVR, FFR decreased significantly (-0.0120 ± 0.0192; P = 0.0045), whereas RFR remained stable (0.0140 ± 0.0673; P = 0.3089). Six months after AVR, FFR decreased (-0.0279 ± 0.0368), whereas RFR increased significantly (+0.0410 ± 0.0487) (P < 0.0001 for both), resulting in 21.5% (21/98) and 39.8% (39/98) of lesions crossing traditional FFR and RFR cutoff lines, respectively. Left ventricular mass decreased significantly (153.68 ± 44.22 g before vs 134.66 ± 37.26 g after; P < 0.0001). MVD was frequently observed at baseline (32.1% abnormal index of microvascular resistance and 68.6% abnormal microvascular resistance reserve) with all microvascular parameters improving after AVR. The most accurate cutoffs to predict ischemia were FFR ≤0.83 and RFR ≤0.85 with comparable accuracy (75%-80%)., Conclusions: In patients with severe AS and CAD, FFR ≤0.83 and RFR ≤0.85 appear to predict myocardial ischemia more accurately. Six months after AVR, FFR decreases, whereas RFR increases significantly with a simultaneous decrease of left ventricular mass and an improvement of microvascular function., Competing Interests: Funding Support and Author Disclosures The Research Foundation Flanders (FWO) supported Dr Minten with a personal research grant (1194521-23N). Dr Minten was supported for this work by Belgian Fund for Heart Surgery grant 489686. Dr Fearon has received institutional research support from Abbott Vascular, Medtronic, and the National Institutes of Health; has consulted with CathWorks; and has stock options with HeartFlow. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background : Septic arthritis (SA) of the native adult hip is a rare orthopaedic emergency requiring prompt diagnosis and treatment. As clinical presentation and laboratory findings are frequently atypical, advanced imaging is often requested. This retrospective study aimed to investigate the prevalence and pattern of extra-articular infectious manifestations and their implications for pre-operative advanced imaging in patients with proven SA of the native hip joint. Methods : Out of 41 patients treated surgically for SA of the native hip during a 16-year period at our tertiary referral hospital, 25 received advanced imaging (computed tomography (CT), magnetic resonance imaging (MRI), or fluorodeoxyglucose positron emission tomography (FDG PET-CT)) prior to initial intervention. For each investigation, a specific set of variables was systematically interpreted, and the most suitable surgical approach was determined. The prognostic value was evaluated by comparing specific outcome measures and the extent of extra-articular involvement. Results : It was found that 32 % of patients had an abscess in one anatomical region, 32 % of patients had abscesses in multiple anatomical regions, and only 36 % of patients had no substantial abscess. Gluteal abscesses were especially common in patients with SA due to contiguous spread. Abscesses in the iliopsoas region were more common in patients with SA due to hematogenous seeding. A combination of several different surgical approaches was deemed necessary to adequately deal with the various presentations. No significant prognostic factors could be identified. Conclusion : We recommend performing advanced imaging in patients with suspected or proven septic arthritis of the native hip joint, as extra-articular abscesses are present in 64 % and might require varying anatomical approaches., Competing Interests: At least one of the (co-)authors is a member of the editorial board of Journal of Bone and Joint Infection. The peer-review process was conducted by an independent editor, and the authors also have no other competing interests to declare., (Copyright: © 2024 Jordi Cools et al.)

Background: Autosomal dominant polycystic kidney disease (ADPKD) is prone to multiple complications, including cyst infection (CyI). 2-Deoxy-2-[ 18 F]fluoro-d-glucose positron emission tomography/computed tomography ([ 18 F]-FDG PET/CT) imaging has proved useful in the diagnosis of renal and hepatic CyI. A 4-point scale comparing the uptake of [ 18 F]-FDG in the suspected infected cyst versus the hepatic physiological background has been recently proposed. We performed an independent validation of this semi-quantitative scoring system., Methods: All ADPKD patients hospitalized between January 2009 and November 2019 who underwent an [ 18 F]-FDG PET/CT for suspected CyI were retrospectively identified using computer-based databases. Medical files were reviewed. CyI was conventionally defined by the combination of fever (≥38°C), abdominal pain, increased plasma C-reactive protein levels (≥70 mg/L), absence of any other cause of inflammation and favourable outcome after ≥21 days of antibiotics. [ 18 F]-FDG uptake of the suspected CyI was evaluated using a 4-point scale comparing the uptake of [ 18 F]-FDG around the infected cysts with the uptake in the hepatic parenchyma. Statistics were performed using SAS version 9.4., Results: Fifty-one [ 18 F]-FDG PET/CT scans in 51 patients were included, of which 11 were cases of CyI. The agreement between the 4-point scale and the gold-standard criteria of CyI was significant [odds ratio of 6.03 for CyI in case of a score ≥3 ( P = .014)]. The corresponding sensitivity, specificity, and positive and negative predictive values of [ 18 F]-FDG PET/CT using the 4-point scale were 64% [Clopper-Pearson 95% confidence interval (CI) 30%-89%], 78% (95% CI 62%-89%), 44% (95% CI 20%-70%) and 89% (95% CI 73%-97%), respectively., Conclusions: Our independent validation cohort confirms the use of a semi-quantitative 4-point scoring system of [ 18 F]-FDG PET/CT imaging in the diagnosis of CyI in patients with ADPKD. Considering its performance metrics with high specificity and negative predictive value, the scoring system is particularly useful to distinguish other causes of clinical inflammation than CyI and as such avoid unnecessarily long antibiotic treatment., Competing Interests: None declared., (© The Author(s) 2023. Published by Oxford University Press on behalf of the ERA.)

Purpose: The aim of this study was to develop a convolutional neural network (CNN) for the automatic detection and segmentation of gliomas using [ 18 F]fluoroethyl-L-tyrosine ([ 18 F]FET) PET., Methods: Ninety-three patients (84 in-house/7 external) who underwent a 20-40-min static [ 18 F]FET PET scan were retrospectively included. Lesions and background regions were defined by two nuclear medicine physicians using the MIM software, such that delineations by one expert reader served as ground truth for training and testing the CNN model, while delineations by the second expert reader were used to evaluate inter-reader agreement. A multi-label CNN was developed to segment the lesion and background region while a single-label CNN was implemented for a lesion-only segmentation. Lesion detectability was evaluated by classifying [ 18 F]FET PET scans as negative when no tumor was segmented and vice versa, while segmentation performance was assessed using the dice similarity coefficient (DSC) and segmented tumor volume. The quantitative accuracy was evaluated using the maximal and mean tumor to mean background uptake ratio (TBR max /TBR mean ). CNN models were trained and tested by a threefold cross-validation (CV) using the in-house data, while the external data was used for an independent evaluation to assess the generalizability of the two CNN models., Results: Based on the threefold CV, the multi-label CNN model achieved 88.9% sensitivity and 96.5% precision for discriminating between positive and negative [ 18 F]FET PET scans compared to a 35.3% sensitivity and 83.1% precision obtained with the single-label CNN model. In addition, the multi-label CNN allowed an accurate estimation of the maximal/mean lesion and mean background uptake, resulting in an accurate TBR max /TBR mean estimation compared to a semi-automatic approach. In terms of lesion segmentation, the multi-label CNN model (DSC = 74.6 ± 23.1%) demonstrated equal performance as the single-label CNN model (DSC = 73.7 ± 23.2%) with tumor volumes estimated by the single-label and multi-label model (22.9 ± 23.6 ml and 23.1 ± 24.3 ml, respectively) closely approximating the tumor volumes estimated by the expert reader (24.1 ± 24.4 ml). DSCs of both CNN models were in line with the DSCs by the second expert reader compared with the lesion segmentations by the first expert reader, while detection and segmentation performance of both CNN models as determined with the in-house data were confirmed by the independent evaluation using external data., Conclusion: The proposed multi-label CNN model detected positive [ 18 F]FET PET scans with high sensitivity and precision. Once detected, an accurate tumor segmentation and estimation of background activity was achieved resulting in an automatic and accurate TBR max /TBR mean estimation, such that user interaction and potential inter-reader variability can be minimized., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: Despite its limitations, [ 123 I]MIBG scintigraphy has been the standard for human norepinephrine transporter (hNET) imaging for several decades. Recently, [ 18 F]MFBG has emerged as a promising PET alternative. This prospective trial aimed to evaluate safety, biodistribution, tumour lesion pharmacokinetics, and lesion targeting of [ 18 F]MFBG and perform a head-to-head comparison with [ 123 I]MIBG in neural crest tumour patients., Methods: Six neural crest tumour patients (4 phaeochromocytoma, 1 paraganglioma, 1 neuroblastoma) with a recent routine clinical [ 123 I]MIBG scintigraphy (interval: - 37-75 days) were included. Adult patients (n = 5) underwent a 30-min dynamic PET, followed by 3 whole-body PET/CT scans at 60, 120, and 180 min after injection of 4 MBq/kg [ 18 F]MFBG. One minor participant underwent a single whole-body PET/CT at 60 min after administration of 2 MBq/kg [ 18 F]MFBG. Normal organ uptake (SUV mean ) and lesion uptake (SUV max ; tumour-to-background ratio (TBR)) were measured. Regional distribution volumes (V T ) were estimated using a Logan graphical analysis in up to 6 lesions per patient. A lesion-by-lesion analysis was performed to compare detection ratios (DR), i.e. fraction of detected lesions, between [ 18 F]MFBG and [ 123 I]MIBG., Results: [ 18 F]MFBG was safe and well tolerated. Its biodistribution was overall similar to that of [ 123 I]MIBG, with prominent uptake in the salivary glands, liver, left ventricle wall and adrenals, and mainly urinary excretion. In the phaeochromocytoma subgroup, the median V T was 37.4 mL/cm 3 (range: 18.0-144.8) with an excellent correlation between V T and SUV mean at all 3 time points (R 2 : 0.92-0.94). Mean lesion SUV max and TBR at 1 h after injection were 19.3 ± 10.7 and 23.6 ± 8.4, respectively. All lesions detected with [ 123 I]MIBG were also observed with [ 18 F]MFBG. The mean DR with [ 123 I]MIBG was significantly lower than with [ 18 F]MFBG (61.0% ± 26.7% vs. 99.8% ± 0.5% at 1 h; p = 0.043)., Conclusion: [ 18 F]MFBG is a promising hNET imaging agent with favourable imaging characteristics and improved lesion targeting compared with [ 123 I]MIBG scintigraphy., Trial Registration: Clinicaltrials.gov : NCT04258592 (Registered: 06 February 2020), EudraCT: 2019-003872-37A., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: 18 F-FDG PET/CT is a valuable diagnostic tool in infective endocarditis (IE). However, the prognostic value is unclear. This study aims to evaluate the prognostic performance of 18 F-FDG PET/CT in native valve endocarditis (NVE) and prosthetic valve endocarditis (PVE)., Methods: We retrospectively included 76 patients treated for definite IE (NVE and PVE) that underwent 18 F-FDG PET/CT between January 2016 and December 2018. Clinical, echocardiographic and 18 F-FDG PET/CT (pathologic valvular 18 F-FDG uptake, extracardiac complications (ECC)) data were collected. The primary endpoint was defined as mortality or recurrence of IE at a one-year follow-up., Results: Pathologic valvular 18 F-FDG uptake was detected in 32 of 57 (56.1%) patients, 30% (9/30) in NVE and 85.2% (23/27) in PVE group. Atrial fibrillation (OR 3.90, 95% CI = 1.14-16.3), prior anticoagulation treatment (OR 6.37, 95% CI = 1.89-26.7), large vegetation (≥ 10 mm) (OR 4.05, 95% CI = 1.14-16.1), perivalvular complications (OR 7.22, 95% CI = 1.68-55.1) and abscess (OR 10.9, 95% CI = 1.84-283) were associated with positive PET/CT. Extracardiac complications were found in 27 of 76 (35.5%) patients, 42.9% (18/42) in the NVE and 26.5% (9/34) in the PVE group. Pathological valvular tracer uptake (HR 1.20, 95% CI = 0.43-3.37) or extracardiac complications (HR 0.58, 95% CI = 0.21-1.62) were not associated with the occurrence of the primary endpoint., Conclusion: Our study could not demonstrate a prognostic value of 18 F-FDG PET/CT in IE, but confirms high diagnostic performance, which may compromise prognostic significance by accelerated optimal treatment because of earlier diagnostic certainty.

To meet the increasing demand for PRRT in the treatment of patients with inoperable/disseminated well-differentiated neuroendocrine tumors (NETs) and to guide optimization strategies, adequate and accessible predictive tools that allow to stratify patients who will benefit from treatment from those who will not are becoming indispensable. Previously, we have investigated the role of baseline [ 68 Ga]Ga-DOTATOC PET tumor uptake and volumetric parameters and a blood-derived inflammatory biomarker, the inflammation-based index (IBI), for outcome prediction in NET patients treated with [ 90 Y]Y-DOTATOC. In this retrospective study in 83 NET patients treated with [ 177 Lu]Lu-DOTATATE in a routine clinical setting, we aimed to evaluate the generalizability of our previous findings to [ 177 Lu]Lu-DOTATATE treatment combined with a pre-therapeutic [ 68 Ga]Ga-DOTATATE PET. A semi-automatic customized SUV threshold-based approach was used for tumor delineation. The previously identified SUV mean cut-off of 13.7 for better survival could not be applied to this patient cohort. Instead, a more optimal cut-off could be identified: an SUV mean lower or equal than 11.2 was associated with worse overall survival (OS) (hazard ratio (HR) 2.28; P = 0.008). Also in line with our previous study, a [ 68 Ga]Ga-DOTATATE-avid tumor volume (TV) higher than 672 mL and an elevated baseline IBI were correlated with worse OS (HR 3.13 (P = 0.0001) and HR 2.00 (P = 0.034), respectively). Multivariate analysis confirmed independent associations between OS and baseline IBI (P = 0.032), SUV mean (P = 0.027) and [ 68 Ga]Ga-DOTATATE-avid TV (P = 0.001). Taking baseline IBI, [ 68 Ga]Ga-DOTATATE-avid TV and [ 68 Ga]Ga-DOTATATE uptake into account may help guide PRRT treatment decisions., Competing Interests: Chris Verslype has received research grants and performed consultancy services for Novartis, Ipsen and Bayer outside the submitted work. Paul M Clement has received study budget funds from AstraZeneca and was advisory board member for AbbVie, AstraZeneca, Bayer, BMS, Daiichi-Sankyo, Leo Pharma, Merck Serono, MSD, Rakuten, Takeda, and Vifor Pharma outside the submitted work. Eric Van Cutsem has received research grants and personal fees for consultancy from Amgen, Bayer, Boehringer Ingelheim, Celgene, Ipsen, Lilly, Roche, Merck Sharp & Dohme, Merck KGaA, Novartis, Roche and Servier outside the submitted work. Christophe M Deroose has been a consultant for Terumo, Ipsen, Sirtex, Bayer and PSI CRO outside the scope of the submitted work. There are no other conflicts of interest., (AJNMMI Copyright © 2022.)

Background and Purpose: Enterovirus infections pose a serious threat for patients with humoral deficiencies and may be lethal, whilst the efficacy of proposed treatment options such as corticosteroids, intravenous immunoglobulins and fluoxetine remains debated., Methods: Viral clearance was investigated in a patient with rituximab-induced B-cell depletion and chronic echovirus 13 (E13) meningoencephalitis/myofasciitis in response to intravenous immunoglobulins and fluoxetine using sequential semi-quantitative E13 viral load measurements by real-time reverse transcription polymerase chain reaction. Fluoxetine concentrations in plasma and cerebrospinal fluid were determined by liquid chromatography mass spectrometry., Results: Intravenous immunoglobulins appeared ineffective in this case of E13 infection, whereas virus clearance in cerebrospinal fluid was obtained after 167 days of oral fluoxetine. Since treatment with corticosteroids resulted in a flare of symptoms, rechallenge with viral load measurements was not attempted., Conclusion: In this report of a patient with rituximab-associated chronic echovirus 13 meningoencephalitis, viral clearance in response to single treatment options is assessed for the first time. Our observations further support the in vivo efficacy of fluoxetine against enteroviral infections. More research is needed to establish its efficacy in different enterovirus strains., (© 2022 European Academy of Neurology.)

Background: Although most guidelines suggest performing a positron emission tomography/computed tomography (PET/CT) with somatostatin receptor (SSTR) ligands for staging of pulmonary carcinoid tumours (PC), only a limited number of studies have evaluated the role of this imaging tool in this specific patient population. The preoperative differentiation between typical carcinoid (TC) and atypical carcinoid (AC) and the extent of dissemination (N/M status) are crucial factors for treatment allocation and prognosis of these patients. Therefore, we performed a pathology-based retrospective analysis of the value of SSTR PET/CT in tumour grading and detection of nodal and metastatic involvement of PC and compared this with the previous literature and with [ 18 F]FDG PET/CT in a subgroup of patients., Methods: SSTR PET/CT scans performed between January 2007 and May 2020 in the context of PC were included. If available, [ 18 F]FDG PET/CT images were also evaluated. The maximum standardized uptake (SUV max ) values of the primary tumour, of the pathologically examined hilar and mediastinal lymph node stations, as well as of the distant metastases, were recorded. Tumoural SUV max values were related to the tumour type (TC versus AC) for both SSTR and [ 18 F]FDG PET/CT in diagnosing and differentiating both tumour types. Nodal SUV max values were compared to the pathological status (N + versus N - ) to evaluate the diagnostic accuracy of SSTR PET/CT in detecting lymph node involvement. Finally, a mixed model analysis of all pathologically proven distant metastatic lesions was performed., Results: A total of 86 SSTR PET/CT scans performed in 86 patients with PC were retrospectively analysed. [ 18 F]FDG PET/CT was available in 46 patients. Analysis of the SUV max values in the primary tumour showed significantly higher SSTR uptake in TC compared with AC (median SUV max 18.4 vs 3.8; p = 0.003) and significantly higher [ 18 F]FDG uptake in AC compared to TC (median SUV max 5.4 vs 3.5; p = 0.038). Receiver operating characteristic (ROC) curve analysis resulted in an area under the curve (AUC) of 0.78 for the detection of TC on SSTR PET/CT and of 0.73 for the detection of AC on [ 18 F]FDG PET/CT. A total of 267 pathologically evaluated hilar and mediastinal lymph node stations were analysed. ROC analysis of paired SSTR/[ 18 F]FDG SUV max values for the detection of metastasis of TC in 83 lymph node stations revealed an AUC of 0.91 for SSTR PET/CT and of 0.74 for [ 18 F]FDG PET/CT (difference 0.17; 95% confidence interval - 0.03 to 0.38; p = 0.10). In a sub-cohort of 10 patients with 12 distant lesions that were pathologically examined due to a suspicious aspect on SSTR PET/CT, a positive predictive value (PPV) of 100% was observed., Conclusion: Our findings confirm the higher SSTR ligand uptake in TC compared to AC and vice versa for [ 18 F]FDG uptake. More importantly, we found a good diagnostic performance of SSTR PET/CT for the detection of hilar and mediastinal lymph node metastases of TC. Finally, a PPV of 100% for SSTR PET/CT was found in a small sub-cohort of patients with pathologically investigated distant metastatic lesions. Taken together, SSTR PET/CT has a very high diagnostic value in the TNM assessment of pulmonary carcinoids, particularly in TC, which underscores its position in European guidelines., (© 2022. The Author(s).)

Objectives: PSMA-PET has become the PET technique of choice to localise the site of biochemically recurrent prostate cancer (PCa). With hybrid PET/MRI, the advantages of MRI are added to molecular characteristic of PET. The aim of this study was to investigate the incremental value of PET/MR versus PET/CT in patients with biochemically recurrent PCa by head-to-head comparison., Methods: Thirty-four patients with biochemically recurrent PCa were prospectively included. They underwent [ 68 Ga]Ga-PSMA-11 PET/CT, followed by simultaneous PET/MR. All PET (PET CT , PET MR ), CT and MR images were evaluated for number of lesions and location. The number of lesions at specific sites was compared using Wilcoxon-sign-rank test. For PET, the maximum and mean standardised uptake values (SUVs) were calculated for each lesion compared using a two-sided paired t test., Results: PET CT and PET MR scans were positive in 19 and 20 patients, detecting 73 and 79 lesions respectively. All lesions detected on PET CT were also detected on PET MR . CT and MRI only were positive in 14 and 17 patients, detecting 38 and 50 lesions, respectively, which was significantly lower than PET CT and PET MR respectively. Combined interpretation showed more lesions on PET/MR than on PET/CT (88 vs 81). No significant difference in detection of presence of local recurrence nor distant metastases was found. SUV mean and SUV max values were significantly higher on PET MR than on PET CT in local recurrence and lymph node metastases., Conclusions: [ 68 Ga]Ga-PSMA-11 PET/MR was able to detect biochemically recurrent PCa at least as accurately as PET/CT for local recurrence, lymph node metastasis and distant metastasis., Key Points: • PSMA PET/MRI detects the location of biochemical recurrence at least as accurately as PET/CT. • Substitution of PET/CT by PET/MRI adds sensitivity in PSMA lesion detection also in the setting of distant recurrence due to both the MR and TOF PET components., (© 2021. European Society of Radiology.)

Although concomitant coronary artery disease (CAD) is frequent in patients with severe aortic stenosis (AS), hemodynamic assessment of CAD severity in patients undergoing valve replacement for severe AS is challenging. Myocardial hypertrophic remodeling interferes with coronary blood flow and may influence the values of fractional flow reserve (FFR) and nonhyperemic pressure ratios (NHPRs). The aim of the current study is to investigate the effect of the AS and its treatment on current indices used for evaluation of CAD. We will compare intracoronary hemodynamics before, immediately after, and 6 mo after aortic valve replacement (AVR) when it is expected that microvascular function has improved. Furthermore, we will compare FFR and resting full-cycle ratio (RFR) with myocardial perfusion single-photon emission-computed tomography (SPECT) as indicators of myocardial ischemia in patients with AS and CAD. One-hundred consecutive patients with AS and intermediate CAD will be prospectively included. Patients will undergo pre-AVR SPECT and intracoronary hemodynamic assessment at baseline, immediately after valve replacement [if transcatheter AVR (TAVR) is chosen], and 6 mo after AVR. The primary end point is the change in FFR 6 mo after AVR. Secondary end points include the acute change of FFR after TAVR, the diagnostic accuracy of FFR versus RFR compared with SPECT for the assessment of ischemia, changes in microvascular function as assessed by the index of microcirculatory resistance (IMR), and the effect of these changes on FFR. The present study will evaluate intracoronary hemodynamic parameters before, immediately after, and 6 mo after AVR in patients with AS and intermediate coronary stenosis. The understanding of the impact of AVR on the assessment of FFR, NHPR, and microvascular function may help guide the need for revascularization in patients with AS and CAD planned for AVR.

A 76-y-old man with hypoosmolar hyponatremia of unknown origin was referred to the nuclear medicine department for 18 F-FDG PET/CT to exclude a malignant cause. Increased 18 F-FDG uptake in both adrenal glands was observed and investigated., (© 2021 by the Society of Nuclear Medicine and Molecular Imaging.)

Localization of parathyroid adenomas is a crucial step to facilitate minimally invasive parathyroidectomy. In this study, we investigated sensitivity and positivity rate of SPECT-based dual isotope parathyroid scintigraphy in detecting parathyroid adenomas, and the effect of medication and parathyroid hormone (PTH)-level on detection of adenomas. Two hundred and thirty-seven patients with primary hyperparathyroidism undergoing dual isotope parathyroid scintigraphy with SPECT-CT in our centre between January 1 st 2013 and December 31 st 2017 were included in this retrospective study. Sensitivity and positivity rate for accurate location of parathyroid adenomas, based on histopathological findings after surgery and follow-up PTH and calcium, were calculated. The impact of pre-operative medication (thyroxin, calcium-antagonists, antacids, vitamin D, bisphosphonates and calcium) and PTH-levels between positive and negative scans was evaluated by using univariate and multivariate analysis, and a ROC analysis respectively. Overall patient-based sensitivity of scintigraphy for finding parathyroid adenomas was 72% for scintigraphy, with a positivity rate of 60%. No significant effect of investigated medication on positivity rate was found. PTH-level was significantly higher in patients with positive scintigraphy (median 96.3 ng/L vs 75.2 ng/L, P < 0.01). Optimum cut-off for detection of adenomas for PTH was 79.4 ng/L with a sensitivity of 67% and a specificity of 63%. In this retrospective cohort, sensitivity and positivity rate of dual-isotope SPECT-CT for parathyroid adenomas were in line with previous studies. No statistically significant influence of medication on positivity of scintigraphy was found, suggesting these medication types should not be stopped prior to scintigraphy. PTH level was no useful parameter to predict positivity of scintigraphic imaging., Competing Interests: None., (AJNMMI Copyright © 2021.)

Background: Detection of the site of recurrence using PSMA-PET/CT is important to guide treatment in patients with biochemical recurrence of prostate cancer (PCa). The aim of this study was to evaluate the positivity rate of [ 18 F]PSMA-1007-PET/CT in patients with biochemically recurrent PCa and identify parameters that predict scan positivity as well as the type and number of detected lesions. This monocentric retrospective study included 137 PCa patients with biochemical recurrence who underwent one or more [ 18 F]PSMA-1007-PET/CT scans between August 2018 and June 2019. PET-positive malignant lesions were classified as local recurrence, lymph node (LN), bone or soft tissue lesions. The association between biochemical/paraclinical parameters, as PSA value, PSA doubling time, PSA velocity, Gleason score (GS) and androgen deprivation therapy (ADT), and scan positivity as well as type and number of detected lesions was evaluated using logistic regression analysis (binary outcomes) and Poisson models (count-type outcomes)., Results: We included 175 [ 18 F]PSMA-1007-PET/CT scans after radical prostatectomy (78%), external beam radiation therapy (8.8%), ADT (7.3%), brachytherapy (5.1%) and high intensity focused ultrasound (0.7%) as primary treatment (median PSA value 1.6 ng/ml). Positivity rate was 80%. PSA value and PSA velocity were significant predictors of scan positivity as well as of the presence of bone and soft tissue lesions and number of bone, LN and soft tissue lesions, both in uni- and/or multivariable analysis. Multivariable analysis also showed prior ADT as predictor of bone and soft tissue lesions, GS as predictor of the number of bone lesions and ongoing ADT as predictor of the number of LN lesions., Conclusion: [ 18 F]PSMA-1007-PET/CT showed a high positivity rate in patients with biochemically recurrent PCa. PSA value and PSA velocity were significant predictors of scan positivity as well as of the presence and number of bone and soft tissue lesions and the number of LN lesions. Our findings can guide clinicians in optimal patient selection for [ 18 F]PSMA-1007-PET/CT and support further research leading to the development of a prediction nomogram.

Background: Salvage radiotherapy (RT) (± androgen deprivation therapy (ADT)) is often used as a treatment in patients with biochemical recurrence (BCR) following radical prostatectomy (RP). Unfortunately, even after RT ± ADT, a significant number of patients will develop 'second' BCR. The aim of this study was to investigate the impact of postoperative treatments (adjuvant/salvage radiotherapy (RT) ± androgen deprivation therapy) on the recurrence pattern in patients with BCR following RP assessed by 11C-Choline PET/CT or 68 Ga-PSMA PET/CT., Methods: Patients who developed BCR following RP and who had at least one positive lesion on PET/CT were retrospectively assessed. Positive spots were mapped as local, lymph node (LN), skeletal or visceral recurrence. A distinction was made between locoregional (prostate bed and pelvic LN) and extrapelvic recurrence (skeletal, visceral and/or extrapelvic LN). Patients were categorized according to postoperative treatment received in three subgroups (RT, ADT and RT + ADT) and compared with the reference group (RP only). The impact of the radiation field was also investigated., Results: We identified 200 patients assessed by 68 Ga-PSMA-11 (80%) or 11 C-Choline PET/CT (20%). Patients who received postoperative RT + ADT had less LN recurrence distal to the common iliac bifurcation (26.7% vs 66.6%; p = 0.0004), but more recurrence to retroperitoneal LN than the reference group (38% vs. 14.4%, p = 0.02). Moreover, the RT + ADT subgroup had more extrapelvic recurrence compared to the reference group (66.2% vs 40.8%, p = 0.02). Patients who received RT to the prostate bed had more recurrence distal to the common iliac bifurcation compared to those who received RT to the prostate bed + pelvic LN (51.6% vs 26.1%, p = 0.0069)., Conclusion: Post-prostatectomy treatments (ADT and/or RT) and the postoperative radiation field (prostate bed vs. prostate bed + pelvis) have a significant impact on the recurrence pattern. This knowledge can help clinicians to counsel their patients on their chances of being eligible for (locoregional) metastasis-directed therapies.

Introduction: We report the case of a young female patient with a technically resectable, nonmetastatic, rectoanal, anaplastic lymphoma kinase gene (ALK)-translocated inflammatory myofibroblastic tumor (IMFT)., Case Presentation: The patient was successfully treated preoperatively with the tyrosine kinase inhibitor (TKI) crizotinib, to downsize the primary tumor, followed by sphincter-sparing surgery, and adjuvant radiotherapy and crizotinib. She is now in follow-up with good sphincter function and with no evidence of active disease., Conclusion: Pre- and postoperative treatment administration of crizotinib can be given with curative intent to patients with locally advanced, nonmetastatic IMFTs to avoid mutilating surgery., (© 2021 S. Karger AG, Basel.)

Background: Transvenous 3 permanent pacemaker-related infection is a severe condition associated with significant morbidity and mortality. Leadless pacemakers may be more resistant to bacterial seeding during bloodstream infection because of its small surface area and encapsulation in the right ventricle. This study reports the incidence and outcomes of bacteraemia in patients implanted with a Micra leadless pacemaker. We present 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) findings obtained in a subgroup of patients., Methods: We report a retrospective cohort study of 155 patients who underwent a Micra TPS implant procedure at the University Hospitals of Leuven between July 2015 and July 2019. We identified the patients who developed an episode of bacteraemia, proved by ≥2 positive blood cultures., Results: Of the 155 patients, 15 patients presented an episode of bacteraemia at a median of 226 days (range: 3-1129) days after the implant procedure. Gram-positive species accounted for 73.3% (n = 11) of the bacteraemia including Staphylococcus (n = 5), Enterococcus (n = 3), and Streptococcus (n = 3). The source of infection was identified in nine patients (60%) including endocarditis in four patients, urinary tract in three patients, and skin in two patients. 18 F-FDG PET/CT imaging performed in six patients did not show sign of infection around the leadless pacemaker. Bacteraemia was resolved in all patients after adequate antibiotherapy. Four patients died early during follow up. For all other patients, there were no recurrence of systemic infection during a median follow up of 263 days (range: 15-1134)., Conclusion: In our small cohort, no leadless pacemaker endocarditis was observed among patients with bacteraemia., (© 2020 Wiley Periodicals LLC.)

Background: Peptide receptor radionuclide therapy (PRRT) is a validated treatment for somatostatin receptor overexpressing neuroendocrine tumors (NETs). The NETTER-1 trial demonstrated a pronounced positive effect on progression-free-survival compared to high dose somatostatin analogs (SSAs), with a strong tendency toward overall survival benefit. Our aim was to investigate the influence of pretreatment with everolimus and/or sunitinib on subacute hematotoxicity of PRRT. To assess the influence of prior treatment with everolimus/sunitinib might be of clinical relevance due to the link between short-term hematotoxicity and increased incidence of late hematotoxicity. Material and methods: Our single-center retrospective study enrolled all patients treated with 177 Lu-DOTATATE PRRT (1-4 cycles of 7.4 GBq), between November 2013 and July 2018. Patients were assigned to two groups according to their pretreatment: no targeted agents ( N  = 41), or targeted agents (everolimus, sunitinib or both; N  = 41). The end point was subacute hematotoxicity, defined as the nadir value between the first administration until 3 months after the last administration, using the CTCAE 4.03 classification. The impact of splenectomy was also explored. Results: Eighty percent of patients had a primary gastroenteropancreatic NET. No statistically significant differences in severe subacute hematotoxicity were seen in the pretreated group vs. the naive group for hemoglobin (grade 3/4: 12% vs. 22%), neither for leucocytes (grade 3/4: 10% vs. 7%), neutrophils (grade 3/4: 5% vs. 7%), lymphocytes (grade 3/4: 49% vs. 37%) and platelets (grade 3/4: 15% vs. 15%). Furthermore, we observed significantly lower toxicity for total white blood cells, lymphocytes and platelets in the subgroup that had splenectomy ( N  = 12). Limitations of this study include the potential bias in lack of use of targeted agents in patients more susceptible to toxicity, and the limited number of patients and events. Conclusions: In a patient cohort with NET pretreated with everolimus and/or sunitinib, we could not demonstrate a significant effect of prior/pretreatment with everolimus and/or sunitinib on the subacute hematotoxicity of 177 Lu-DOTATATE PRRT.

We present a case of a 79 year old patient with a medical history of unilateral nerve-sparing radical prostatectomy due to a pT3aN0 (Gleason score 7) prostate carcinoma. Because of slightly elevated prostate specific antigen (PSA) level (0.35ng/dL), a fluorine-18-prostate specific membrane antigen ( 18 F-PSMA)-1007 positron emission tomography/computed tomography (PET/CT) scan was performed, showing no signs of malignant recurrence. However, a moderately PSMA-avid nodular lesion was observed in the left occipital region with homogeneous contrast enhancement, suggestive for a meningioma, which was confirmed on magnetic resonance imaging (MRI). One year later, the lesion was resected due to a small but significant growth. Histology confirmed the diagnosis of a transitional type meningioma (WHO grade 1).

A 34-year-old man with history of Hodgkin lymphoma presented 7 months after allogeneic stem cell transplantation with an unexplained severe musculoskeletal pain syndrome. A Tc-MDP bone SPECTCT showed multiple foci with moderate to intense bone uptake across the axial and appendicular skeleton consistent with periostitis. The patient had been on voriconazole daily for 4 months to treat an Aspergillus pneumonia, and in the absence of other causes, a drug-induced periostitis was suspected. Voriconazole was changed to posaconazole with complete resolution of the musculoskeletal symptoms within 3 weeks.

In patients with neurofibromatosis type 1, transformation of neurofibromas into a malignant peripheral nerve sheath tumor (MPNST) is a severe complication of the disease. Fluorine-18-fluorodeoxyglucose PET/computed tomography (PET/CT) is a viable option for detecting malignant tumors in neurofibromatosis type 1 patients. The aim of this review was to assess the diagnostic performance of the most frequently used parameters of PET/CT in detecting MPNST. An extensive computer search was performed using the Cochrane Library, Pubmed, and Medline/Embase databases. Two reviewers independently extracted data of relevant studies and assessed the methodological quality (QUADAS-2). The diagnostic performance of PET/CT parameters in individual studies was determined by calculating a diagnostic odds ratio (DOR) using the absolute numbers of true-positive, true-negative, false-positive, and false-negative test results. A total of eight studies were included, of which three evaluated the standardized uptake value as a diagnostic parameter, two assessed the tumor-to-liver (T/L) ratio, and three articles described both parameters. The cut-off values for maximum standardized uptake value (SUVmax) ranged from 3.2 to 4.5; for the T/L ratio, the cut-off values were between 1.0 and 4.3. The sensitivity and specificity ranged from 90 to 100% and from 80 to 100%, respectively (SUVmax). T/L ratios were associated with 92-100% sensitivity and 72-94% specificity. The corresponding DORs ranged from 57 to 145 (SUVmax) and 35 to 655 (T/L ratio). Both the SUV and the T/L ratio are associated with high sensitivity combined with acceptable specificity in detecting MPNST. There is a tendency toward higher DORs using the T/L ratio, but the number of studies is limited.

Purpose: To investigate thyroid gland characteristics on 18 F-FDG positron emission tomography/computed tomography (PET/CT) imaging in patients with neurofibromatosis type 1 (NF1)., Subjects and Methods: Thyroid gland characteristics of patients with a clinical diagnosis of NF1 who underwent 18 F-FDG PET/CT imaging for the first time to distinguish benign neurofibroma from malignant peripheral nerve sheath tumor (MPNST) at our institution ( n = 69) were compared to PET/CT imaging of sarcoidosis ( n = 25) and early stage lung cancer (T 1 N 0 M 0 tumors, n = 15) patients., Results: Two NF1 patients (3%) showed a diffuse 18 F-FDG uptake in the thyroid gland, 2 patients (3%) had an irregular uptake, and 7 patients (10%) had a focal uptake. Among the sarcoidosis patients, 1 showed a diffuse uptake (4%) and 1 had an irregular uptake (4%). In the early stage lung cancer group, 1 patient showed a diffuse uptake (7%) and 1 had a focal uptake (7%). NF1 patients had larger mean thyroid volume and mean SUV max compared to sarcoidosis patients but not compared to early stage lung cancer patients. Four NF1 patients were diagnosed with multinodular goiter, 2 patients were diagnosed with benign chronic lymphocytic thyroiditis, 1 patient had metastasis to the thyroid, and 1 patient had medullary thyroid cancer., Conclusion: Even though NF1 patients did not show an increased risk of thyroid incidentaloma on PET/CT compared to previous studies on non-thyroid cancer patients, the incidence shows that awareness of possible thyroid disease is important.