Publications by authors named "Ian Alberts"

74 Publications

Assessment of malignancy and PSMA expression of uncertain bone foci in [F]PSMA-1007 PET/CT for prostate cancer-a single-centre experience of PET-guided biopsies.

Eur J Nucl Med Mol Imaging 2022 Apr 28. Epub 2022 Apr 28.

Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Freiburgstr. 18, CH-3010, Bern, Switzerland.

Purpose: Uncertain focal bone uptake (UBU) with intensive radiopharmaceutical avidity are frequently observed in patients undergoing [F]PSMA-1007 PET/CT for the detection of prostate cancer (PC). Such foci can pose diagnostic conundrums and risk incorrect staging. The aim of this short communication is to share the results of PET-guided biopsies of such foci.

Methods: A retrospective analysis revealed 10 patients who were referred to our department for PET-guided biopsy of UBU visible in a previous [F]PSMA-1007 PET/CT. [F]-PSMA-1007 PET-guided biopsy was conducted for 11 PSMA-avid bone foci in these 10 patients. The biopsy materials were analysed for tissue typing, and immunohistochemistry (IHC) was performed for prostate-specific-membrane-antigen (PSMA) expression. The scans were analysed by two experienced physicians in a consensus read for clinical characteristics and radiopharmaceutical uptake of foci.

Results: One out of 11 (9.1%) of the foci biopsied was confirmed as bone metastasis of PC with intense PSMA-expression, while 10/11 (90.9%) foci were revealed to be unremarkable bone tissue without evidence of PSMA expression at IHC. Amongst all bone foci assessed by biopsy, eight were visually classified as being at high risk of malignancy in the PET/CT (SUVmean 12.0 ± 8.1; SUVmax 18.8 ± 13.1), three as equivocal (SUVmean 4.6 ± 2.1; SUVmax 7.2 ± 3.0) and zero as low risk. No UBU had any CT correlate.

Conclusions: This cohort biopsy revealed that a small but relevant number of UBU are true metastases. For those confirmed as benign, no PSMA expression at IHC was observed, suggesting a non-PSMA mediated cause for intensive [F]PSMA-1007 uptake of which the reason remains unclear. Readers must interpret such foci with caution in order to reduce the risk of erroneous staging and subsequent treatment. PET-guided biopsy, particularly in the absence of morphological changes in the CT, can be a useful method to clarify such foci.
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http://dx.doi.org/10.1007/s00259-022-05745-5DOI Listing
April 2022

Abbreviated scan protocols to capture F-FDG kinetics for long axial FOV PET scanners.

Eur J Nucl Med Mol Imaging 2022 Mar 12. Epub 2022 Mar 12.

Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.

Purpose: Kinetic parameters from dynamic F-fluorodeoxyglucose (FDG) imaging offer complementary insights to the study of disease compared to static clinical imaging. However, dynamic imaging protocols are cumbersome due to the long acquisition time. Long axial field-of-view (LAFOV) PET scanners (> 70 cm) have two advantages for dynamic imaging over clinical PET scanners with a standard axial field-of-view (SAFOV; 16-30 cm). The large axial coverage enables multi-organ dynamic imaging in a single bed position, and the high sensitivity may enable clinically routine abbreviated dynamic imaging protocols.

Methods: In this work, we studied two abbreviated protocols using data from a 65-min dynamic F-FDG scan: (A) dynamic imaging immediately post-injection (p.i.) for variable durations, and (B) dynamic imaging immediately p.i. for variable durations plus a 1-h p.i. (5-min-long) datapoint. Nine cancer patients were imaged on the Biograph Vision Quadra (Siemens Healthineers). Time-activity curves over the lesions (N = 39) were fitted using the Patlak graphical analysis and a 2-tissue-compartment (2C, k = 0) model for variable scan durations (5-60 min). Kinetic parameters from the complete dataset served as the reference. Lesions from all cancers were grouped into low, medium, and high flux groups, and bias and precision of K (Patlak) and K, K, k, and k (2C) were calculated for each group.

Results: Using only early dynamic data with the 2C (or Patlak) model, accurate quantification of K required at least 50 (or 55) min of dynamic data for low flux lesions, at least 30 (or 40) min for medium flux lesions, and at least 15 (or 20) min for high flux lesions to achieve both 10% bias and precision. The addition of the final (5-min) datapoint allowed for accurate quantification of K with a bias and precision of 10% using only 10-15 min of early dynamic data for either model.

Conclusion: Dynamic imaging for 10-15 min immediately p.i. followed by a 5-min scan at 1-h p.i can accurately and precisely quantify F-FDG on a long axial FOV scanner, potentially allowing for more widespread use of dynamic F-FDG imaging.
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http://dx.doi.org/10.1007/s00259-022-05747-3DOI Listing
March 2022

Differential diagnosis of parkinsonism based on deep metabolic imaging indices.

J Nucl Med 2022 Mar 3. Epub 2022 Mar 3.

University of Bern.

The clinical presentations of early idiopathic Parkinson's disease (PD) substantially overlap with those of atypical parkinsonian syndromes like multiple system atrophy (MSA) and progressive supranuclear palsy (PSP). This study aimed to develop metabolic imaging indices based on deep learning to support the differential diagnosis of these conditions. A benchmark Huashan parkinsonian PET imaging (HPPI, China) database including 1275 parkinsonian patients and 863 non-parkinsonian subjects with F-FDG PET images was established to support artificial intelligence development. A 3D deep convolutional neural network was developed to extract deep metabolic imaging (DMI) indices, which was blindly evaluated in an independent cohort with longitudinal follow-up from the HPPI, and an external German cohort of 90 parkinsonian patients with different imaging acquisition protocols. The proposed DMI indices had less ambiguity space in the differential diagnosis. They achieved sensitivities of 98.1%, 88.5%, and 84.5%, and specificities of 90.0%, 99.2%, and 97.8% for the diagnosis of PD, MSA, and PSP in the blind test cohort. In the German cohort, They resulted in sensitivities of 94.1%, 82.4%, 82.1%, and specificities of 84.0%, 99.9%, 94.1% respectively. Employing the PET scans independently achieved comparable performance to the integration of demographic and clinical information into the DMI indices. The DMI indices developed on the HPPI database show potential to provide an early and accurate differential diagnosis for parkinsonism and is robust when dealing with discrepancies between populations and imaging acquisitions.
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http://dx.doi.org/10.2967/jnumed.121.263029DOI Listing
March 2022

Image-level trajectory inference of tau pathology using variational autoencoder for Flortaucipir PET.

Eur J Nucl Med Mol Imaging 2022 Feb 28. Epub 2022 Feb 28.

Department of Nuclear Medicine, Inselspital, University of Bern, Freiburgstrasse 18, 3010, Bern, Switzerland.

Purpose: Alzheimer's disease (AD) studies revealed that abnormal deposition of tau spreads in a specific spatial pattern, namely Braak stage. However, Braak staging is based on post mortem brains, each of which represents the cross section of the tau trajectory in disease progression, and numerous studies were reported that do not conform to that model. This study thus aimed to identify the tau trajectory and quantify the tau progression in a data-driven approach with the continuous latent space learned by variational autoencoder (VAE).

Methods: A total of 1080 [F]Flortaucipir brain positron emission tomography (PET) images were collected from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. VAE was built to compress the hidden features from tau images in latent space. Hierarchical agglomerative clustering and minimum spanning tree (MST) were applied to organize the features and calibrate them to the tau progression, thus deriving pseudo-time. The image-level tau trajectory was inferred by continuously sampling across the calibrated latent features. We assessed the pseudo-time with regard to tau standardized uptake value ratio (SUVr) in AD-vulnerable regions, amyloid deposit, glucose metabolism, cognitive scores, and clinical diagnosis.

Results: We identified four clusters that plausibly capture certain stages of AD and organized the clusters in the latent space. The inferred tau trajectory agreed with the Braak staging. According to the derived pseudo-time, tau first deposits in the parahippocampal and amygdala, and then spreads to the fusiform, inferior temporal lobe, and posterior cingulate. Prior to the regional tau deposition, amyloid accumulates first.

Conclusion: The spatiotemporal trajectory of tau progression inferred in this study was consistent with Braak staging. The profile of other biomarkers in disease progression agreed well with previous findings. We addressed that this approach additionally has the potential to quantify tau progression as a continuous variable by taking a whole-brain tau image into account.
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http://dx.doi.org/10.1007/s00259-021-05662-zDOI Listing
February 2022

Diagnostic accuracy of [F]PSMA-1007 PET/CT in biochemical recurrence of prostate cancer.

Eur J Nucl Med Mol Imaging 2022 Jun 24;49(7):2436-2444. Epub 2022 Jan 24.

Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Freiburgstr. 18, 3010, Bern, Switzerland.

Aim: Despite increasing use for the detection of biochemically recurrent prostate cancer (rPC), the diagnostic accuracy of positron emission tomography/computed tomography (PET/CT) with [F]PSMA-1007 remains only partially investigated. The aim of this study was to determine the sensitivity (SE), specificity (SP), positive predictive value (PPV), and negative predictive value (NPV) for PC-local recurrence and metastases on a per region basis.

Materials And Methods: One hundred seventy-seven consecutive patients undergoing [F]PSMA-1007 PET/CT for rPC were retrospectively analysed. Six body regions were defined: prostate fossa, pelvic lymph nodes (LN), retroperitoneal LN, supradiaphragmatic LN, bones, and soft tissue. A region was counted positive if at least one PSMA-positive lesion suspicious for PC was observed. Confirmation of a true-positive PSMA-avid lesion was defined as positive by histopathology, fall in serum prostate-specific antigen (PSA) (> 50%) after targeted therapy or confirmatory further CT, MRI, PET/CT, or bone scan imaging. Regions where additional imaging was able to confirm the absence of suspicious PC lesions or regions outside exclusively targeted RT with serum PSA decline (> 50%) were counted as true-negative regions. SE, SP, PPV, and NPV were calculated for all six regions.

Results: The overall PET-positivity rate was 91%. Conclusive follow-up for affirmation or refutation of a PSMA-positive lesion was available for 81/152 patients on a per region basis. In this subgroup, overall sensitivity, specificity, PPV, and NPV were 95% (CI: 0.90-0.98), 89% (CI: 0.83-0.93), 86% (0.80-0.90), and 96% (CI: 0.92-0.98), respectively. On a per region basis, PPV was 97% (CI: 0.83-0.99) for local recurrence, 93% (CI: 0.78-0.98) for pelvic LN, 87% (CI: 0.62-0.96) for retroperitoneal LN, 82% (CI: 0.52-0.95) for supradiaphragmatic LN, and 79% (0.65-0.89) for bone lesions. The number of solid organ metastases (n = 6) was too small for an accurate statistical analysis.

Conclusion: The known high PET-positivity rate of [F]PSMA-1007 PET/CT in rPC was confirmed, with corresponding high (> 90%) sensitivity and NPV on a per region basis. However, overall PPV was limited (86%), particularly for bone lesions (79%), which are a potential diagnostic weaknesses when using this tracer.
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http://dx.doi.org/10.1007/s00259-022-05693-0DOI Listing
June 2022

Tumor microenvironment mechanisms and bone metastatic disease progression of prostate cancer.

Cancer Lett 2022 04 17;530:156-169. Epub 2022 Jan 17.

Department for BioMedical Research, Urology Research Laboratory, University of Bern, Bern, Switzerland. Electronic address:

During disease progression from primary towards metastatic prostate cancer (PCa), and in particular bone metastases, the tumor microenvironment (TME) evolves in parallel with the cancer clones, altering extracellular matrix composition (ECM), vasculature architecture, and recruiting specialized tumor-supporting cells that favor tumor spread and colonization at distant sites. We introduce the clinical profile of advanced metastatic PCa in terms of common genetic alterations. Findings from recently developed models of PCa metastatic spread are discussed, focusing mainly on the role of the TME (mainly matrix and fibroblast cell types), at distinct stages: premetastatic niche orchestrated by the primary tumor towards the metastatic site and bone metastasis. We report evidence of premetastatic niche formation, such as the mechanisms of distant site conditioning by extracellular vesicles, chemokines and other tumor-derived mechanisms, including altered cancer cell-ECM interactions. Furthermore, evidence supporting the similarities of stroma alterations among the primary PCa and bone metastasis, and contribution of TME to androgen deprivation therapy resistance are also discussed. We summarize the available bone metastasis transgenic mouse models of PCa from a perspective of pro-metastatic TME alterations during disease progression and give an update on the current diagnostic and therapeutic radiological strategies for bone metastasis clinical management.
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http://dx.doi.org/10.1016/j.canlet.2022.01.015DOI Listing
April 2022

Using radiomics-based modelling to predict individual progression from mild cognitive impairment to Alzheimer's disease.

Eur J Nucl Med Mol Imaging 2022 Jun 15;49(7):2163-2173. Epub 2022 Jan 15.

Department of Nuclear Medicine, University Hospital Bern, Bern, Switzerland.

Background: Predicting the risk of disease progression from mild cognitive impairment (MCI) to Alzheimer's disease (AD) has important clinical significance. This study aimed to provide a personalized MCI-to-AD conversion prediction via radiomics-based predictive modelling (RPM) with multicenter 18F-fluorodeoxyglucose positron emission tomography (FDG PET) data.

Method: FDG PET and neuropsychological data of 884 subjects were collected from Huashan Hospital, Xuanwu Hospital, and from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. First, 34,400 radiomic features were extracted from the 80 regions of interest (ROIs) for all PET images. These features were then concatenated for feature selection, and an RPM model was constructed and validated on the ADNI dataset. In addition, we used clinical data and the routine semiquantification index (standard uptake value ratio, SUVR) to establish clinical and SUVR Cox models for further comparison. FDG images from local hospitals were used to explore RPM performance in a separate cohort of individuals with healthy controls and different cognitive levels (a complete AD continuum). Finally, correlation analysis was conducted between the radiomic biomarkers and neuropsychological assessments.

Results: The experimental results showed that the predictive performance of the RPM Cox model was better than that of other Cox models. In the validation dataset, Harrell's consistency coefficient of the RPM model was 0.703 ± 0.002, while those of the clinical and SUVR models were 0.632 ± 0.006 and 0.683 ± 0.009, respectively. Moreover, most crucial imaging biomarkers were significantly different at different cognitive stages and significantly correlated with cognitive disease severity.

Conclusion: The preliminary results demonstrated that the developed RPM approach has the potential to monitor progression in high-risk populations with AD.
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http://dx.doi.org/10.1007/s00259-022-05687-yDOI Listing
June 2022

First results on kinetic modelling and parametric imaging of dynamic F-FDG datasets from a long axial FOV PET scanner in oncological patients.

Eur J Nucl Med Mol Imaging 2022 05 4;49(6):1997-2009. Epub 2022 Jan 4.

Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse 18, 3010, Bern, Switzerland.

Purpose: To investigate the kinetics of F-fluorodeoxyglucose (F-FDG) by positron emission tomography (PET) in multiple organs and test the feasibility of total-body parametric imaging using an image-derived input function (IDIF).

Methods: Twenty-four oncological patients underwent dynamic F-FDG scans lasting 65 min using a long  axial FOV (LAFOV) PET/CT system. Time activity curves (TAC) were extracted from semi-automated segmentations of multiple organs, cerebral grey and white matter, and from vascular structures. The tissue and tumor lesion TACs were fitted using an irreversible two-tissue compartment (2TC) and a Patlak model. Parametric images were also generated using direct and indirect Patlak methods and their performances were evaluated.

Results: We report estimates of kinetic parameters and metabolic rate of glucose consumption (MR) for different organs and tumor lesions. In some organs, there were significant differences between MR values estimated using 2TC and Patlak models. No statistically significant difference was seen between MR values estimated using 2TC and Patlak methods in tumor lesions (paired t-test, P = 0.65). Parametric imaging showed that net influx (K) images generated using direct and indirect Patlak methods had superior tumor-to-background ratio (TBR) to standard uptake value (SUV) images (3.1- and 3.0-fold mean increases in TBR, respectively). Influx images generated using the direct Patlak method had twofold higher contrast-to-noise ratio in tumor lesions compared to images generated using the indirect Patlak method.

Conclusion: We performed pharmacokinetic modelling of multiple organs using linear and non-linear models using dynamic total-body F-FDG images. Although parametric images did not reveal more tumors than SUV images, the results confirmed that parametric imaging furnishes improved tumor contrast. We thus demonstrate the feasibility of total-body kinetic modelling and parametric imaging in basic research and oncological studies. LAFOV PET can enhance dynamic imaging capabilities by providing high sensitivity parametric images and allowing total-body pharmacokinetic analysis.
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http://dx.doi.org/10.1007/s00259-021-05623-6DOI Listing
May 2022

A cross-scanner and cross-tracer deep learning method for the recovery of standard-dose imaging quality from low-dose PET.

Eur J Nucl Med Mol Imaging 2022 05 24;49(6):1843-1856. Epub 2021 Dec 24.

Department of Nuclear Medicine, University of Bern, Bern, Switzerland.

Purpose: A critical bottleneck for the credibility of artificial intelligence (AI) is replicating the results in the diversity of clinical practice. We aimed to develop an AI that can be independently applied to recover high-quality imaging from low-dose scans on different scanners and tracers.

Methods: Brain [F]FDG PET imaging of 237 patients scanned with one scanner was used for the development of AI technology. The developed algorithm was then tested on [F]FDG PET images of 45 patients scanned with three different scanners, [F]FET PET images of 18 patients scanned with two different scanners, as well as [F]Florbetapir images of 10 patients. A conditional generative adversarial network (GAN) was customized for cross-scanner and cross-tracer optimization. Three nuclear medicine physicians independently assessed the utility of the results in a clinical setting.

Results: The improvement achieved by AI recovery significantly correlated with the baseline image quality indicated by structural similarity index measurement (SSIM) (r = -0.71, p < 0.05) and normalized dose acquisition (r = -0.60, p < 0.05). Our cross-scanner and cross-tracer AI methodology showed utility based on both physical and clinical image assessment (p < 0.05).

Conclusion: The deep learning development for extensible application on unknown scanners and tracers may improve the trustworthiness and clinical acceptability of AI-based dose reduction.
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http://dx.doi.org/10.1007/s00259-021-05644-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9015984PMC
May 2022

Drosophila yakuba - Tsc1.

MicroPubl Biol 2021 12;2021. Epub 2021 Nov 12.

The University of Alabama, Tuscaloosa, AL USA.

Gene Model for the ortholog of in the DyakCAF1 assembly (GCA_000005975.1).
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http://dx.doi.org/10.17912/micropub.biology.000474DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8590729PMC
November 2021

Comparing the clinical performance and cost efficacy of [Ga]Ga-PSMA-11 and [F]PSMA-1007 in the diagnosis of recurrent prostate cancer: a Markov chain decision analysis.

Eur J Nucl Med Mol Imaging 2021 Nov 13. Epub 2021 Nov 13.

Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, CH-3010, Bern, Switzerland.

Purpose: Amongst others, [Ga]Ga-PSMA-11 and [F]PSMA-1007 are available for the detection of recurrent prostate cancer (rPC). There are currently limited data comparing the performance of these two radioligands with respect to clinical outcomes or their cost efficacy, which this study aims to address.

Methods: Two hundred and forty-four patients undergoing PSMA PET/CT for rPC were retrospectively analysed for this study (one hundred and twenty two with each radiopharmaceutical) to generate rates of PET positivity, negativity and unclear findings. Patients underwent follow-up to determine the rate of additional examinations and to confirm PET findings. A Markov chain decision analysis was implemented to model clinical decision-making processes and to analyse clinical performance of the two tracers. We determine their clinical cost efficacies using cost data from several countries where both radiotracers are in routine use.

Results: The PET positivity rate was non-significantly higher for [F]PSMA-1007 compared to [Ga]Ga-PSMA-11 (91.8% vs. 86.9%, p = 0.68), whereas the rate of uncertain findings was significantly greater (17.2% vs. 8.25%, p = 0.02). The probability of a true positive finding was higher for [Ga]Ga-PSMA-11 (0.90, 95% CI 0.70-0.98) vs. [F]PSMA-1007 (0.81, 95% CI 0.66-0.91). A significantly (p < 0.0001) higher PPV for [Ga]Ga-PSMA-11 (0.99, 95% CI 0.99-1.0 vs. 0.86) was found compared to [F]PSMA-1007 (0.86, 95% CI 0.82-1.00). Intervention efficacy analysis favoured [Ga]Ga-PSMA-11, where the number needed to image (to achieve a true positive finding) was 10.58 and the number needed to image to harm (to achieve a false positive finding) was - 8.08. A cost efficacy analysis favours [Ga]Ga-PSMA-11 in three of the four jurisdictions analysed where health economic data was available (Switzerland, Israel, Australia) and [F]PSMA-1007 in one jurisdiction (Denmark).

Conclusion: The analysis reveals a non-significantly higher PET positivity rate for [F]PSMA-1007, but finds significantly greater rates of uncertain findings and false positive findings when compared to [Ga]Ga-PSMA-11. We find differences in the two tracers in terms of clinical performance and cost efficacy. The method presented herein is generalisable and can be used with clinical or cost data for other countries or tracers.
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http://dx.doi.org/10.1007/s00259-021-05620-9DOI Listing
November 2021

PSMA-Ligand Uptake in Disseminated Epidermoid Cysts in a PSMA PET/CT of a Patient With Recurrent Prostate Cancer.

Clin Nucl Med 2021 Dec;46(12):e598-e599

From the Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.

Abstract: PSMA PET/CT is routinely used for the detection of prostate cancer (PC). However, increased PSMA-ligand uptake has been described in a variety of benign and malignant tissues. A 71-year-old man with biochemical recurrence of PC initially treated with radical prostatectomy was referred for PSMA-ligand PET/CT. Apart from 1 lymph node with intense PSMA-ligand uptake, suspicious for metastasis, disseminated PSMA-ligand-avid subcutaneous lesions were seen. Histopathology of 1 of these lesions revealed an epidermoid cyst. Physicians should remain cognizant of non-PC-related causes of increased PSMA-ligand uptake, of which this case represent yet another example.
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http://dx.doi.org/10.1097/RLU.0000000000003749DOI Listing
December 2021

The Alteration of Brain Interstitial Fluid Drainage with Myelination Development.

Aging Dis 2021 Oct 1;12(7):1729-1740. Epub 2021 Oct 1.

3Institute of Medical Technology, Peking University Health Science Center, Beijing, China.

The integrity of myelination is crucial for maintaining brain interstitial fluid (ISF) drainage in adults; however, the mechanism of ISF drainage with immature myelin in the developing brain remains unknown. In the present study, the ISF drainage from the caudate nucleus (Cn) to the ipsilateral cortex was studied at different developmental stages of the rat brain (P 10, 20, 30, 40, 60, 80, 10-80). The results show that the traced ISF drained to the cortex from Cn and to the thalamus in an opposite direction before P30. From P40, we found impeded drainage to the thalamus due to myelin maturation. This altered drainage was accompanied by enhanced cognitive and social functions, which were consistent with those in the adult rats. A significant difference in diffusion parameters was also demonstrated between the extracellular space (ECS) before and after P30. The present study revealed the alteration of ISF drainage regulated by myelin at different stages during development, indicating that a regional ISF homeostasis may be essential for mature psychological and cognitive functions.
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http://dx.doi.org/10.14336/AD.2021.0305DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8460314PMC
October 2021

FDG uptake in axillary lymph nodes after COVID-19 vaccination - a pitfall in a case of highly suspicious lymph node metastases of malignant melanoma.

Nuklearmedizin 2021 12 19;60(6):456-457. Epub 2021 Aug 19.

Inselspital, Bern University Hospital, Department of Nuclear Medicine, University of Bern, Bern, Switzerland.

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http://dx.doi.org/10.1055/a-1561-2046DOI Listing
December 2021

Drosophila yakuba - Tsc1.

MicroPubl Biol 2021 Jun 24;2021. Epub 2021 Jun 24.

The University of Alabama, Tuscaloosa, AL USA.

Gene Model for in the 's DyakCAF1 assembly (GCA_000005975.1).
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http://dx.doi.org/10.17912/micropub.biology.000407DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8226385PMC
June 2021

Feasibility of late acquisition [68Ga]Ga-PSMA-11 PET/CT using a long axial field-of-view PET/CT scanner for the diagnosis of recurrent prostate cancer-first clinical experiences.

Eur J Nucl Med Mol Imaging 2021 12 21;48(13):4456-4462. Epub 2021 Jun 21.

Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Freiburgstr. 18, 3010, Bern, Switzerland.

Purpose: While acquisition of images in [ Ga]Ga-PSMA-11 following longer uptake times can improve lesion uptake and contrast, resultant imaging quality and count statistics are limited by the isotope's half-life (68 min). Here, we present a series of cases demonstrating that when performed using a long axial field-of-view (LAFOV) PET/CT system, late imaging is feasible and can even provide improved image quality compared to regular acquisitions.

Methods: In this retrospective case series, we report our initial experiences with 10 patients who underwent standard imaging at 1 h p.i. following administration of 192 ± 36 MBq [ Ga]Ga-PSMA-11 with additional late imaging performed at 4 h p.i. Images were acquired in a single bed position for 6 min at 1 h p.i. and 16 min p.i. at 4 h p.i. using a LAFOV scanner (106 cm axial FOV). Two experienced nuclear medicine physicians reviewed all scans in consensus and evaluated overall image quality (5-point Likert scale), lesion uptake in terms of standardised uptake values (SUV), tumour to background ratio (TBR) and target-lesion signal to background noise (SNR).

Results: Subjective image quality as rated on a 5-point Likert scale was only modestly lower for late acquisitions (4.2/5 at 4 h p.i.; 5/5 1 h p.i.), TBR was significantly improved (4 h: 3.41 vs 1 h: 1.93, p < 0.001) and SNR was improved with borderline significance (4 h: 33.02 vs 1 h: 24.80, p = 0.062) at later imaging. Images were obtained with total acquisition times comparable to routine examinations on standard axial FOV scanners.

Conclusion: Late acquisition in tandem with a LAFOV PET/CT resulted in improvements in TBR and SNR and was associated with only modest impairment in subjective visual imaging quality. These data show that later acquisition times for [ Ga]Ga-PSMA-11 may be preferable when performed on LAFOV systems.
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http://dx.doi.org/10.1007/s00259-021-05438-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8566391PMC
December 2021

Diagnosis and staging of hepatobiliary malignancies: Potential incremental value of (18)F-FDG-PET/MRI compared to MRI of the liver.

Nuklearmedizin 2021 Oct 8;60(5):355-367. Epub 2021 Jun 8.

Radiology, University Hospitals Cleveland Medical Center and Case Western Reserve University, Cleveland, United States.

Objective:  The purpose of the study was to investigate the potential added value of F-FDG-PET/MRI (functional information derived from PET) over standard diagnostic liver MRI (excellent soft tissue characterization) in diagnosing and staging suspected primary hepatobiliary malignancies including extrahepatic cholangiocarcinoma (ECC), intrahepatic cholangiocellular carcinoma (ICC) and gallbladder cancer (GBCA).

Methods:  Twenty consecutive patients with suspected hepatobiliary malignancy were included in this retrospective study. All patients underwent combined whole-body (WB) F-FDG-PET/MRI including contrast-enhanced MRI of the liver, contrast-enhanced WB-MRI and WB F-FDG-PET. Two experienced readers staged hepatobiliary disease using TNM criteria: first based on MRI alone and then based on combined F-FDG-PET/MRI. Subsequently, the impact of FDG-PET/MRI on clinical management compared to MRI alone was recorded. Histopathologic proof served as the reference standard.

Results:  Hepatobiliary neoplasms were present in 16/20 patients (ECC n = 3, ICC n = 8, GBCA n = 5), two patients revealed benign disease, two were excluded. TNM staging with F-FDG-PET/MRI was identical to MRI alone in 11/18 (61.1 %) patients and correctly changed the stage in 4/18 (22.2 %), resulting in a change in management for 2/4 patients (11.1 %). F-FDG-PET/MRI was false-positive in 3/18 cases (16.7 %). Both MRI and F-FDG-PET/MRI were falsely positive in 1 case without malignancy.

Conclusions:  A small incremental benefit of F-FDG-PET/MRI over standard MRI of the liver was observed. However, in some cases F-FDG-PET/MRI may lead to false-positive findings. Overall there is seemingly limited role of F-FDG-PET/MRI in patients with suspected hepatobiliary malignancy.
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http://dx.doi.org/10.1055/a-1486-3671DOI Listing
October 2021

Prostate Cancer Theranostics: PSMA Targeted Therapy.

PET Clin 2021 Jul;16(3):391-396

Department of Nuclear Medicine, University Hospital Münster, Münster, Germany; West German Cancer Center (WTZ). Electronic address:

Prostate-specific membrane antigen (PSMA) has been the subject of numerous studies within the last 3 decades. PSMA-targeted imaging and therapy have significantly changed the management of patients with prostate cancer in various disease stages, especially in advanced metastasized castration-resistant prostate cancer. Lutetium-177-conjugated PSMA-617 or PSMA-I&T (Lu-PSMA) has shown promising results in multicenter retrospective and monocenter prospective trials. The aim of this review is to provide an overview of the history and current and future developments of PSMA-targeted therapy. A special focus of this review is on PSMA PET-guided management of patients receiving PSMA-targeted radioligand therapy.
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http://dx.doi.org/10.1016/j.cpet.2021.03.004DOI Listing
July 2021

Prostate Cancer Theranostics: From Target Description to Imaging.

PET Clin 2021 Jul;16(3):383-390

Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.

Prostate-specific membrane antigen-PET/computed tomography (PSMA-PET/CT) is the investigation of choice for imaging prostate cancer. Demonstrating high diagnostic accuracy, PSMA-PET/CT detects disease at very early stages of recurrence, where the chances of a definitive cure may be at their greatest. A number of PSMA-radioligands are in established clinical routine, and there are currently only limited data and no single tracer can clearly be advocated over the others at present. Further clinical trial data, comparing and contrasting radiotracers and reporting outcome-based data are necessary to further increase the implementation of this very promising imaging modality.
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http://dx.doi.org/10.1016/j.cpet.2021.03.003DOI Listing
July 2021

Authors' reply: PSMA-PET: is the time to say goodbye to metabolic radiopharmaceuticals in prostate cancer?

Eur J Nucl Med Mol Imaging 2021 07 4;48(8):2307-2308. Epub 2021 May 4.

Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, CH-3010, Bern, Switzerland.

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http://dx.doi.org/10.1007/s00259-021-05376-2DOI Listing
July 2021

A comprehensive review of imaging findings in COVID-19 - status in early 2021.

Eur J Nucl Med Mol Imaging 2021 07 1;48(8):2500-2524. Epub 2021 May 1.

Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.

Medical imaging methods are assuming a greater role in the workup of patients with COVID-19, mainly in relation to the primary manifestation of pulmonary disease and the tissue distribution of the angiotensin-converting-enzyme 2 (ACE 2) receptor. However, the field is so new that no consensus view has emerged guiding clinical decisions to employ imaging procedures such as radiography, computer tomography (CT), positron emission tomography (PET), and magnetic resonance imaging, and in what measure the risk of exposure of staff to possible infection could be justified by the knowledge gained. The insensitivity of current RT-PCR methods for positive diagnosis is part of the rationale for resorting to imaging procedures. While CT is more sensitive than genetic testing in hospitalized patients, positive findings of ground glass opacities depend on the disease stage. There is sparse reporting on PET/CT with [F]-FDG in COVID-19, but available results are congruent with the earlier literature on viral pneumonias. There is a high incidence of cerebral findings in COVID-19, and likewise evidence of gastrointestinal involvement. Artificial intelligence, notably machine learning is emerging as an effective method for diagnostic image analysis, with performance in the discriminative diagnosis of diagnosis of COVID-19 pneumonia comparable to that of human practitioners.
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http://dx.doi.org/10.1007/s00259-021-05375-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8087891PMC
July 2021

The influence of digital PET/CT on diagnostic certainty and interrater reliability in [Ga]Ga-PSMA-11 PET/CT for recurrent prostate cancer.

Eur Radiol 2021 Oct 15;31(10):8030-8039. Epub 2021 Apr 15.

Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Freiburgstr. 18, 3010, Bern, Switzerland.

Objective: To investigate the impact of digital PET/CT on diagnostic certainty, patient-based sensitivity and interrater reliability.

Methods: Four physicians retrospectively evaluated two matched cohorts of patients undergoing [Ga]Ga-PSMA-11 PET/CT on a digital (dPET/CT n = 65) or an analogue scanner (aPET/CT n = 65) for recurrent prostate cancer between 11/2018 and 03/2019. The number of equivocal and pathological lesions as well as the frequency of discrepant findings and the interrater reliability for the two scanners were compared.

Results: dPET/CT detected more lesions than aPET/CT (p < 0.001). A higher number of pathological scans were observed for dPET/CT (83% vs. 57%, p < 0.001). The true-positive rate at follow-up was 100% for dPET/CT compared to 84% for aPET/CT (p < 0.001). The proportion of lesions rated as non-pathological as a total of all PSMA-avid lesions detected for dPET/CT was comparable to aPET/CT (61.8% vs. 57.0%, p = 0.99). Neither a higher rate of diagnostically uncertain lesions (11.5% dPET/CT vs. 13.7% aPET/CT, p = 0.95) nor discrepant scans (where one or more readers differed in opinion as to whether the scan is pathological) were observed (18% dPET/CT vs. 17% aPET/CT, p = 0.76). Interrater reliability for pathological lesions was excellent for both scanner types (Cronbach's α = 0.923 dPET/CT; α = 0.948 aPET/CT) and interrater agreement was substantial for dPET/CT (Krippendorf's α = 0.701) and almost perfect in aPET/CT (α = 0.802).

Conclusions: A higher detection rate for pathological lesions for dPET/CT compared with aPET/CT in multiple readers was observed. This improved sensitivity was coupled with an improved true-positive rate and was not associated with increased diagnostic uncertainty, rate of non-specific lesions, or reduced interrater reliability.

Key Points: • New generation digital scanners detect more cancer lesions in men with prostate cancer. • When using digital scanners, the doctors are able to diagnose prostate cancer lesions with better certainty • When using digital scanners, the doctors do not disagree with each other more than with other scanner types.
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http://dx.doi.org/10.1007/s00330-021-07870-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8452558PMC
October 2021

Clinical performance of long axial field of view PET/CT: a head-to-head intra-individual comparison of the Biograph Vision Quadra with the Biograph Vision PET/CT.

Eur J Nucl Med Mol Imaging 2021 07 2;48(8):2395-2404. Epub 2021 Apr 2.

Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Freiburgstr. 18, 3010, Bern, Switzerland.

Purpose: To investigate the performance of the new long axial field-of-view (LAFOV) Biograph Vision Quadra PET/CT and a standard axial field-of-view (SAFOV) Biograph Vision 600 PET/CT (both: Siemens Healthineers) system using an intra-patient comparison.

Methods: Forty-four patients undergoing routine oncological PET/CT were prospectively included and underwent a same-day dual-scanning protocol following a single administration of either F-FDG (n = 20), F-PSMA-1007 (n = 16) or Ga-DOTA-TOC (n = 8). Half the patients first received a clinically routine examination on the SAFOV (FOV 26.3 cm) in continuous bed motion and then immediately afterwards on the LAFOV system (10-min acquisition in list mode, FOV 106 cm); the second half underwent scanning in the reverse order. Comparisons between the LAFOV at different emulated scan times (by rebinning list mode data) and the SAFOV were made for target lesion integral activity, signal to noise (SNR), target lesion to background ratio (TBR) and visual image quality.

Results: Equivalent target lesion integral activity to the SAFOV acquisitions (16-min duration for a 106 cm FOV) were obtained on the LAFOV in 1.63 ± 0.19 min (mean ± standard error). Equivalent SNR was obtained by 1.82 ± 1.00 min LAFOV acquisitions. No statistically significant differences (p > 0.05) in TBR were observed even for 0.5 min LAFOV examinations. Subjective image quality rated by two physicians confirmed the 10 min LAFOV to be of the highest quality, with equivalence between the LAFOV and the SAFOV at 1.8 ± 0.85 min. By analogy, if the LAFOV scans were maintained at 10 min, proportional reductions in applied radiopharmaceutical could obtain equivalent lesion integral activity for activities under 40 MBq and equivalent doses for the PET component of <1 mSv.

Conclusion: Improved image quality, lesion quantification and SNR resulting from higher sensitivity were demonstrated for an LAFOV system in a head-to-head comparison under clinical conditions. The LAFOV system could deliver images of comparable quality and lesion quantification in under 2 min, compared to routine SAFOV acquisition (16 min for equivalent FOV coverage). Alternatively, the LAFOV system could allow for low-dose examination protocols. Shorter LAFOV acquisitions (0.5 min), while of lower visual quality and SNR, were of adequate quality with respect to target lesion identification, suggesting that ultra-fast or low-dose acquisitions can be acceptable in selected settings.
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http://dx.doi.org/10.1007/s00259-021-05282-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8241747PMC
July 2021

Correction to: Comparing the diagnostic performance of radiotracers in recurrent prostate cancer: a systematic review and network meta-analysis.

Eur J Nucl Med Mol Imaging 2021 Aug;48(9):3014-3016

Department of Nuclear Medicine. Inselspital, Bern University Hospital, University of Bern, Street: Freiburgstr. 18, CH-3010, Bern, Switzerland.

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http://dx.doi.org/10.1007/s00259-021-05300-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8496592PMC
August 2021

Digital PET/CT allows for shorter acquisition protocols or reduced radiopharmaceutical dose in [F]-FDG PET/CT.

Ann Nucl Med 2021 Apr 7;35(4):485-492. Epub 2021 Feb 7.

Department of Nuclear Medicine. Inselspital, Bern University Hospital, University of Bern, Freiburgstr. 18, 3010, Bern, Switzerland.

Purpose: To establish the feasibility of shorter acquisition times (and by analogy, applied activity) on tumour detection and lesion contrast in digital PET/CT.

Methods: Twenty-one randomly selected patients who underwent oncological [F]-FDG PET/CT on a digital PET/CT were retrospectively evaluated. Scan data were anonymously obtained and reconstructed in list-mode acquisition for a standard 2 min/bed position (bp), 1 min/bp and 30 s/bp (100%, 50% and 25% time or applied activity, respectively). Scans were randomized and read by two nuclear medicine physicians in a consensus read. Readers were blind to clinical details. Scans were evaluated for the number of pathological lesions detected. Measured uptake for lesions was evaluated by maximum and mean standardized uptake value (SUVmax and SUVmean, respectively) and tumour-to-backround ratio (TBR) were compared. Agreement between the three acquisitions was compared by Krippendorf's alpha.

Results: Overall n = 100 lesions were identified in the 2 min and 1 min/bp acquisitions and n = 98 lesions in the 30 s/bp acquisitions. Agreement between the three acquisitions with respect to lesion number and tumour-to-background ratio showed almost perfect agreement (K's α = 0.999). SUVmax, SUVmean and TBR likewise showed > 98% agreement, with longer acquisitions being associated with slightly higher mean TBR (2 min/bp 7.94 ± 4.41 versus 30 s/bp 7.84 ± 4.22, p < 0.05).

Conclusion: Shorter acquisition times have traditionally been associated with reduced lesion detectability or the requirement for larger amounts of radiotracer activity. These data confirm that this is not the case for new-generation digital PET scanners, where the known higher sensitivity results in clinically adequate images for shorter acquisitions. Only a small variation in the semi-quantitative parameters SUVmax, SUVmean and TBR was seen, confirming that either reduction of acquisition time or (by analogy) applied activity can be reduced as much as 75% in digital PET/CT without apparent clinical detriment.
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http://dx.doi.org/10.1007/s12149-021-01588-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7981298PMC
April 2021

Comparing the diagnostic performance of radiotracers in recurrent prostate cancer: a systematic review and network meta-analysis.

Eur J Nucl Med Mol Imaging 2021 08 6;48(9):2978-2989. Epub 2021 Feb 6.

Department of Nuclear Medicine. Inselspital, Bern University Hospital, University of Bern, Street: Freiburgstr. 18, CH-3010, Bern, Switzerland.

Purpose: Many radiotracers are currently available for the detection of recurrent prostate cancer (rPC), yet many have not been compared head-to-head in comparative imaging studies. There is therefore an unmet need for evidence synthesis to guide evidence-based decisions in the selection of radiotracers. The objective of this study was therefore to assess the detection rate of various radiotracers for the rPC.

Methods: The PUBMED, EMBASE, and the EU and NIH trials databases were searched without date or language restriction for comparative imaging tracers for 13 radiotracers of principal interest. Key search terms included 18F-PSMA-1007, 18F-DCPFyl, 68Ga-PSMA-11, 18F-PSMA-11, 68Ga-PSMA-I&T, 68Ga-THP-PSMA, 64Cu-PSMA-617, 18F-JK-PSMA-7, 18F-Fluciclovine, 18F-FABC, 18F-Choline, 11C-Choline, and 68Ga-RM2. Studies reporting comparative imaging data in humans in rPC were selected. Single armed studies and matched pair analyses were excluded. Twelve studies with eight radiotracers were eligible for inclusion. Two independent reviewers screened all studies (using the PRISMA-NMA statement) for inclusion criteria, extracted data, and assessed risk of bias (using the QUADAS-2 tool). A network meta-analysis was performed using Markov-Chain Monte Carlo Bayesian analysis to obtain estimated detection rate odds ratios for each tracer combination.

Results: A majority of studies were judged to be at risk of publication bias. With the exception of 18F-PSMA-1007, little difference in terms of detection rate was revealed between the three most commonly used PSMA-radiotracers (Ga-PSMA-11, F-PSMA-1007, F-DCFPyl), which in turn showed clear superiority to choline and fluciclovine using the derived network.

Conclusion: Differences in patient-level detection rates were observed between PSMA- and choline-radiotracers. However, there is currently insufficient evidence to favour one of the four routinely used PSMA-radioligands (PSMA-11, PSMA-1007, PSMA-I&T, and DCFPyl) over another owing to the limited evidence base and risk of publication bias revealed by our systematic review. A further limitation was lack of reporting on diagnostic accuracy, which might favour radiotracers with low specificity in an analysis restricted only to detection rate. The NMA derived can be used to inform the design of future clinical trials and highlight areas where current evidence is weak.
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http://dx.doi.org/10.1007/s00259-021-05210-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8263438PMC
August 2021

Combination of Forced Diuresis with Additional Late Imaging in Ga-PSMA-11 PET/CT: Effects on Lesion Visibility and Radiotracer Uptake.

J Nucl Med 2021 09 5;62(9):1252-1257. Epub 2021 Feb 5.

Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; and

Renal excretion of some prostate-specific membrane antigen (PSMA) ligands and consequently increased bladder activity can obscure locally relapsing prostate cancer lesions in PSMA PET/CT. Furthermore, additional late imaging in PSMA PET/CT provides a useful method to clarify uncertain findings. The aim of this retrospective study was to investigate a modified imaging protocol combining late additional imaging with hydration and forced diuresis in individuals undergoing additional late scanning for uncertain lesions or low prostate-specific antigen. We compared an older protocol with a newer one. In the old protocol, patients undergoing Ga-PSMA-11 PET/CT were examined at 90 min after injection, with 1 L of oral hydration beginning at 30 min after injection and 20 mg of furosemide given intravenously at 1 h after injection, followed by additional late imaging at 2.5 h after injection without further preparation. In the new protocol, a second group received the same procedure as before, with an additional 0.5 L of oral hydration and 10 mg of furosemide intravenously 30 min before the late imaging. We examined 132 patients (76 with the old protocol and 56 with the new one) with respect to urinary bladder activity (SUV), prostate cancer lesion uptake (SUV), and lesion contrast (ratio of tumor SUV to bladder SUV for local relapses and ratio of tumor SUV to gluteal-muscle SUV for nonlocal prostate cancer lesions). Bladder activity was significantly greater for the old protocol in the late scans than for the new protocol (ratio of bladder activity at 2.5 h to bladder activity at 1.5 h, 2.33 ± 1.17 vs. 1.37 ± 0.50, < 0.0001). Increased tumor SUV and contrast were seen at 2.5 h compared with 1.5 h ( < 0.0001 for old protocol; = 0.02 for new protocol). Increased bladder activity for the old protocol resulted in decreased lesion-to-bladder contrast, which was not the case for the new protocol. Tumor-to-background ratios increased at late imaging for both protocols, but the increase was significantly lower for the new protocol. For the old protocol, comparing the 1.5-h to the 2.5-h acquisitions, 4 lesions in 4 patients (4/76 = 5.2% of the cohort) were visible at the postdiuresis 1.5-h acquisition but not at 2.5 h, having been obscured as a result of the higher bladder activity. In the new protocol, 2 of 56 (3.6%) patients had lesions visible only at late imaging, and 2 patients had lesions that could be better discriminated at late imaging. Although the combination of diuretics and hydration can be a useful method to increase the visualization and detectability of locally recurrent prostate cancer in standard Ga-PSMA-11 PET/CT, their effects do not sufficiently continue into additional late imaging. Additional diuresis and hydration are recommended to improve the visibility, detection, and diagnostic certainty of local recurrences.
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http://dx.doi.org/10.2967/jnumed.120.257741DOI Listing
September 2021

Extended perfusion defects in lung perfusion-SPECT/CT in a case of fatal COVID-19 pneumonia.

Nuklearmedizin 2021 06 26;60(3):249-251. Epub 2021 Jan 26.

Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.

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http://dx.doi.org/10.1055/a-1333-0226DOI Listing
June 2021

The influence of colour scale in lesion detection and patient-based sensitivity in [68Ga]Ga-PSMA-PET/CT.

Nucl Med Commun 2021 May;42(5):495-502

Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.

Objective: To investigate the influence of colour scales on the interpretation of [68Ga]Ga-PSMA-11 PET/CT for the diagnosis of recurrent prostate cancer.

Methods: 50 consecutive patients who underwent [68Ga]Ga-PSMA-11 PET/CT for recurrent prostate cancer were selected for this retrospective study. The scans were randomised, anonymised and read by five different readers first in the visually nonlinear colour scale 'PET-rainbow'. Scans were then rerandomised and read in the visually linear colour scale 'hot-metal new'. For each scan in each colour scale the numbers of pathological, equivocal and benign lesions were noted. Scans where the majority of readers (≥3) reported at least one PET-positive lesion were recorded as 'pathological'. Patient-level sensitivity was obtained by composite standard with 14.8 ± 1.2 months of follow-up.

Results: Increased numbers of lesions per patient were reported for all readers in PET-rainbow compared to hot-metal new (37.4 ± 15.2 vs. 33.9 ± 16.4, respectively, P = 0.0005). On a per-patient basis, 43 scans were rated pathological in PET-rainbow, compared to 39 in hot-metal new. Follow-up was available for 30 patients confirming 26 pathological scans with positive follow-up in PET-rainbow, and 23 in hot-metal new. Three pathological scans were missed in hot-metal new. Patient-level sensitivity was higher for PET-rainbow (0.96) compared to hot-metal new (0.85). Inter-reader reliability was higher for hot-metal new (Fleiss κ = 0.76) compared to PET-rainbow (Fleiss κ = 0.60).

Conclusion: Use of PET-rainbow was associated with improved lesion detection and sensitivity compared to hot-metal new, although at cost of reduced inter-rater agreement. Consequently, the use of PET-rainbow for clinical routine and future studies involving [68Ga]Ga-PSMA-11 is recommended.
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http://dx.doi.org/10.1097/MNM.0000000000001364DOI Listing
May 2021

is a non-lethal modifier of the mosaic eye phenotype in .

MicroPubl Biol 2021 Jan 18;2021. Epub 2021 Jan 18.

University of Detroit Mercy, Detroit, MI USA.

Genetic screens have been used to identify genes involved in the regulation of different biological processes. We identified growth mutants in a Flp/FRT screen using the eye to identify conditional regulators of cell growth and cell division. One mutant identified from this screen, , was mapped and characterized by researchers in undergraduate genetics labs as part of the Fly-CURE. We find that is a non-lethal genetic modifier of the mosaic eye phenotype.
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http://dx.doi.org/10.17912/micropub.biology.000359DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7812380PMC
January 2021
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