A phase I prospective, non-randomized trial of autologous dendritic cell-based cryoimmunotherapy in patients with metastatic castration-resistant prostate cancer.

Metastatic castration-resistant prostate cancer (mCRPC) is an immunologically cold disease with dismal outcomes. Cryoablation destroys cancer tissue, releases tumor-associated antigens and creates a pro-inflammatory microenvironment, while dendritic cells (DCs) activate immune responses through processing of antigens. Immunotherapy combinations could enhance the anti-tumor efficacy. This open-label, single-arm, single-center phase I trial determined the safety and tolerability of combining cryoablation and autologous immature DC, without and with checkpoint inhibitors. Immune responses and clinical outcomes were evaluated. Patients with mCRPC, confirmed metastases and intact prostate gland were included. The first participants underwent prostate cryoablation with intratumoral injection of autologous DCs in a 3 + 3 design. In the second part, patients received cryoablation, the highest acceptable DC dose, and checkpoint inhibition with either ipilimumab or pembrolizumab. Sequentially collected information on adverse events, quality of life, blood values and images were analyzed by standard descriptive statistics. Neither dose-limiting toxicities nor adverse events > grade 3 were observed in the 18 participants. Results indicate antitumor activity through altered T cell receptor repertoires, and 33% durable (> 46 weeks) clinical benefit with median 40.7 months overall survival. Post-treatment pain and fatigue were associated with circulating tumor cell (CTC) presence at inclusion, while CTC responses correlated with clinical outcomes. This trial demonstrates that cryoimmunotherapy in mCRPC is safe and well tolerated, also for the highest DC dose (2.0 × 108) combined with checkpoint inhibitors. Further studies focusing on the biologic indications of antitumor activity and immune system activation could be considered through a phase II trial focusing on treatment responses and immunologic biomarkers.

Optimising preoperative risk stratification tools for prostate cancer using mpMRI.

PURPOSE: To improve preoperative risk stratification for prostate cancer (PCa) by incorporating multiparametric MRI (mpMRI) features into risk stratification tools for PCa, CAPRA and D'Amico. METHODS: 807 consecutive patients operated on by robot-assisted radical prostatectomy at our institution during the period 2010-2015 were followed to identify biochemical recurrence (BCR). 591 patients were eligible for final analysis. We employed stepwise backward likelihood methodology and penalised Cox cross-validation to identify the most significant predictors of BCR including mpMRI features. mpMRI features were then integrated into image-adjusted (IA) risk prediction models and the two risk prediction tools were then evaluated both with and without image adjustment using receiver operating characteristics, survival and decision curve analyses. RESULTS: 37 patients suffered BCR. Apparent diffusion coefficient (ADC) and radiological extraprostatic extension (rEPE) from mpMRI were both significant predictors of BCR. Both IA prediction models reallocated more than 20% of intermediate-risk patients to the low-risk group, reducing their estimated cumulative BCR risk from approximately 5% to 1.1%. Both IA models showed improved prognostic performance with a better separation of the survival curves. CONCLUSION: Integrating ADC and rEPE from mpMRI of the prostate into risk stratification tools improves preoperative risk estimation for BCR. KEY POINTS: • MRI-derived features, ADC and EPE, improve risk stratification of biochemical recurrence. • Using mpMRI to stratify prostate cancer patients improves the differentiation between risk groups. • Using preoperative mpMRI will help urologists in selecting the most appropriate treatment.

EMG changes during continuous intraoperative neuromonitoring with sustained recurrent laryngeal nerve traction in a porcine model.

PURPOSE: Traction is the most common cause of injury to the recurrent laryngeal nerve (RLN) in endocrine neck surgery. The purpose of this study was to evaluate specific alterations to the electromyogram (EMG) and verify safe alarm limits in a porcine model of sustained traction of the RLN using continuous intraoperative neuromonitoring (C-IONM). METHODS: Sixteen Norwegian Landrace pigs were anesthetized and intubated with a tracheal tube with a stick-on laryngeal electrode. EMG was recorded at baseline (BL) and during sustained traction applied to each RLN until 70 % amplitude decrease from BL, and during 30-min recovery. RESULTS: In 29 nerves at risk (NAR), BL amplitude and latency values were 1098 ± 418 (586-2255) µV (mean ± SD (range)) (right vagus) and 845 ± 289 (522-1634) µV (left vagus), and 4.7 ± 0.5 (4.1-5.9) ms and 7.9 ± 0.8 (6.7-9.6) ms, respectively. At 50 % amplitude decrease, latency increased by 14.0 ± 5.7 % (right side) and 14.5 ± 9.1 % (left side) compared with BL. Corresponding values for 70 % amplitude depression were 17.9 ± 6.1 % and 17.3 ± 12.8 %. Traction time to 50 and 70 % amplitude decrease ranged from 3 to 133 min and 3.9-141 min, respectively. In 16 NAR (55 %), time from 50 to 70 % reduction in amplitude was ≤5 min, but in six NAR (21 %) ≤1 min. In only 11 (38 %) of 29 nerves, the amplitude recovered to more than 50 % of BL. CONCLUSIONS: Latency increase may be the first warning of RLN stretch injury. Given the short interval between 50 and 70 % amplitude reduction of the EMG, amplitude reduction by 50 % can be taken as an appropriate alert limit.

Estimated cumulative radiation dose received by diagnostic imaging during staging and treatment of operable Ewing sarcoma 2005-2012.

BACKGROUND: Patients with Ewing sarcoma are subject to various diagnostic procedures that incur exposure to ionising radiation. OBJECTIVE: To estimate the radiation doses received from all radiologic and nuclear imaging episodes during diagnosis and treatment, and to determine whether 18F-fluorodeoxyglucose positron emission tomography - computed tomography (18F-FDG PET-CT) is a major contributor of radiation. MATERIALS AND METHODS: Twenty Ewing sarcoma patients diagnosed in Norway in 2005-2012 met the inclusion criteria (age <30 years, operable disease, uncomplicated chemotherapy and surgery, no metastasis or residual disease within a year of diagnosis). Radiation doses from all imaging during the first year were calculated for each patient. RESULTS: The mean estimated cumulative radiation dose for all patients was 34 mSv (range: 6-70), radiography accounting for 3 mSv (range: 0.2-12), CT for 13 mSv (range: 2-28) and nuclear medicine for 18 mSv (range: 2-47). For the patients examined with PET-CT, the mean estimated cumulative effective dose was 38 mSv, of which PET-CT accounted for 14 mSv (37%). CONCLUSION: There was large variation in number and type of examinations performed and also in estimated cumulative radiation dose. The mean radiation dose for patients examined with PET-CT was 23% higher than for patients not examined with PET-CT.

Impact of EMG Changes in Continuous Vagal Nerve Monitoring in High-Risk Endocrine Neck Surgery.

BACKGROUND: Continuous vagal intraoperative neuromonitoring (CIONM) of the recurrent laryngeal nerve (RLN) may reduce the risk of RLN lesions during high-risk endocrine neck surgery such as operation for large goiter potentially requiring transsternal surgery, advanced thyroid cancer, and recurrence. METHODS: Fifty-five consecutive patients (41 female, median age 61 years, 87 nerves at risk) underwent high-risk endocrine neck surgery. CIONM was performed using the commercially available NIM-Response 3.0 nerve monitoring system with automatic periodic stimulation (APS) and matching endotracheal tube electrodes (Medtronic Inc.). All CIONM events (decreased amplitude/increased latency) were recorded. RESULTS: APS malfunction occurred on three sides (3%). A total of 138 CIONM events were registered on 61 sides. Of 138, 47 (34%) events were assessed as imminent (13 events) or potentially imminent (34 events) lesions, whereas 91 (66%) were classified as artifacts. Loss of signal was observed in seven patients. Actions to restore the CIONM baseline were undertaken in 58/138 (42%) events with a median 60 s required per action. Four RLN palsies (3 transient, 1 permanent) occurred: one in case of CIONM malfunction, two sudden without any significant previous CIONM event, and one without any CIONM event. The APS vagus electrode led to temporary damage to the vagus nerve in two patients. CONCLUSIONS: CIONM may prevent RLN palsies by timely recognition of imminent nerve lesions. In high-risk endocrine neck surgery, CIONM may, however, be limited in its utility by system malfunction, direct harm to the vagus nerve, and particularly, inability to indicate RLN lesions ahead in time.

F18-FDG-PET for recurrent differentiated thyroid cancer: a systematic meta-analysis.

BACKGROUND: Positron emission tomography (PET) with fluor-18-deoxy-glucose (FDG) is widely used for diagnosing recurrent or metastatic disease in patients with differentiated thyroid cancer (DTC). PURPOSE: To assess the diagnostic accuracy of FDG-PET for DTC in patients after ablative therapy. MATERIAL AND METHODS: A systematic search was conducted in Medline/PubMed, EMBASE, Cochrane Library, Web of Science, and Open Grey looking for all English-language original articles on the performance of FDG-PET in series of at least 20 patients with DTC having undergone ablative therapy including total thyroidectomy. Diagnostic performance measures were pooled using Reitsma's bivariate model. RESULTS: Thirty-four publications between 1996 and 2014 met the inclusion criteria. Pooled sensitivity and specificity were 79.4% (95% confidence interval [CI], 73.9-84.1) and 79.4% (95% CI, 71.2-85.4), respectively, with an area under the curve of 0.858. CONCLUSION: F18-FDG-PET is a useful method for detecting recurrent DTC in patients having undergone ablative therapy.

[Gastroparesis - causes, diagnosis and treatment]. / Gastroparese - årsaker, diagnostikk og behandling.

BACKGROUND Gastroparesis is a motility disorder of the stomach. The symptoms are non-specific: nausea and vomiting are most common. Stomach pains, early satiety, postprandial fullness and bloating are also frequent symptoms. Current diagnostic criteria require delayed gastric emptying in the absence of any detectable mechanical obstruction. In this review article we elucidate the causes, assessment and treatment options.MATERIAL AND METHOD Structured article search in Embase and PubMed.RESULTS A number of conditions can lead to gastroparesis. The most frequent somatic cause is diabetes mellitus. Gastroparesis may also be iatrogenically inflicted by means of surgery or drugs. It may be difficult to discriminate between functional dyspepsia and idiopathic gastroparesis. Examination is based on patient history, gastroscopy and measurement of the rate of gastric emptying. Biochemical tests are also relevant for differential diagnosis. The treatment is primarily symptomatic, and consists of dietary measures, fluid therapy, drugs, gastric electrical stimulation, or endoscopic or surgical intervention in the form of insertion of a feeding tube for nutrition and abdominal relief, pyloroplasty or gastrectomy.INTERPRETATION Gastroparesis is a serious motility disorder. The condition may have significant consequences for patients, entailing reduced quality of life, reduced workforce participation and a considerable need for health assistance.

Default-mode network functional connectivity is closely related to metabolic activity.

Over the last decade, the brain's default-mode network (DMN) and its function has attracted a lot of attention in the field of neuroscience. However, the exact underlying mechanisms of DMN functional connectivity, or more specifically, the blood-oxygen level-dependent (BOLD) signal, are still incompletely understood. In the present study, we combined 2-deoxy-2-[(18) F]fluoroglucose positron emission tomography (FDG-PET), proton magnetic resonance spectroscopy ((1) H-MRS), and resting-state functional magnetic resonance imaging (rs-fMRI) to investigate more directly the association between local glucose consumption, local glutamatergic neurotransmission and DMN functional connectivity during rest. The results of the correlation analyzes using the dorsal posterior cingulate cortex (dPCC) as seed region showed spatial similarities between fluctuations in FDG-uptake and fluctuations in BOLD signal. More specifically, in both modalities the same DMN areas in the inferior parietal lobe, angular gyrus, precuneus, middle, and medial frontal gyrus were positively correlated with the dPCC. Furthermore, we could demonstrate that local glucose consumption in the medial frontal gyrus, PCC and left angular gyrus was associated with functional connectivity within the DMN. We did not, however, find a relationship between glutamatergic neurotransmission and functional connectivity. In line with very recent findings, our results lend further support for a close association between local metabolic activity and functional connectivity and provide further insights towards a better understanding of the underlying mechanism of the BOLD signal.

Post-PET ultrasound improves specificity of 18F-FDG-PET for recurrent differentiated thyroid cancer while maintaining sensitivity.

BACKGROUND: Positron emission tomography (PET) using fluor-18-deoxyglucose (18F-FDG) with or without computed tomography (CT) is generally accepted as the most sensitive imaging modality for diagnosing recurrent differentiated thyroid cancer (DTC) in patients with negative whole body scintigraphy with iodine-131 (I-131). PURPOSE: To assess the potential incremental value of ultrasound (US) over 18F-FDG-PET-CT. MATERIAL AND METHODS: Fifty-one consecutive patients with suspected recurrent DTC were prospectively evaluated using the following multimodal imaging protocol: (i) US before PET (pre-US) with or without fine needle biopsy (FNB) of suspicious lesions; (ii) single photon emission computed tomography (≥3 GBq I-131) with co-registered CT (SPECT-CT); (iii) 18F-FDG-PET with co-registered contrast-enhanced CT of the neck; (iv) US in correlation with the other imaging modalities (post-US). Postoperative histology, FNB, and long-term follow-up (median, 2.8 years) were taken as composite gold standard. RESULTS: Fifty-eight malignant lesions were identified in 34 patients. Forty lesions were located in the neck or upper mediastinum. On receiver operating characteristics (ROC) analysis, 18F-FDG-PET had a limited lesion-based specificity of 59% at a set sensitivity of 90%. Pre-US had poor sensitivity and specificity of 52% and 53%, respectively, increasing to 85% and 94% on post-US, with knowledge of the PET/CT findings (P < 0.05 vs. PET and pre-US). Multimodal imaging changed therapy in 15 out of 51 patients (30%). CONCLUSION: In patients with suspected recurrent DTC, supplemental targeted US in addition to 18F-FDG-PET-CT increases specificity while maintainin sensitivity, as non-malignant FDG uptake in cervical lesions can be confirmed.

1.5-T multiparametric MRI using PI-RADS: a region by region analysis to localize the index-tumor of prostate cancer in patients undergoing prostatectomy.

BACKGROUND: The use of multiparametric magnetic resonance imaging (mpMRI) to detect and localize prostate cancer has increased in recent years. In 2010, the European Society of Urogenital Radiology (ESUR) published guidelines for mpMRI and introduced the Prostate Imaging Reporting and Data System (PI-RADS) for scoring the different parameters. PURPOSE: To evaluate the reliability and diagnostic performance of endorectal 1.5-T mpMRI using the PI-RADS to localize the index tumor of prostate cancer in patients undergoing prostatectomy. MATERIAL AND METHODS: This institutional review board IRB-approved, retrospective study included 63 patients (mean age, 60.7 years, median PSA, 8.0). Three observers read mpMRI parameters (T2W, DWI, and DCE) using the PI-RADS, which were compared with the results from whole-mount histopathology that analyzed 27 regions of interest. Inter-observer agreement was calculated as well as sensitivity, specificity, positive predictive value (PPV), and negative predicted value (NPV) by dichotomizing the PI-RADS criteria scores ≥3. A receiver-operating curve (ROC) analysis was performed for the different MR parameters and overall score. RESULTS: Inter-observer agreement on the overall score was 0.41. The overall score in the peripheral zone achieved sensitivities of 0.41, 0.60, and 0.55 with an NPV of 0.80, 0.84, and 0.83, and in the transitional zone, sensitivities of 0.26, 0.15, and 0.19 with an NPV of 0.92, 0.91, and 0.92 for Observers 1, 2, and 3, respectively. The ROC analysis showed a significantly increased area under the curve (AUC) for the overall score when compared to T2W alone for two of the three observers. CONCLUSION: 1.5 T mpMRI using the PI-RADS to localize the index tumor achieved moderate reliability and diagnostic performance.

Severe nigrostriatal degeneration without clinical parkinsonism in patients with polymerase gamma mutations.

The role of mitochondria in the pathogenesis of neurodegeneration is an area of intense study. It is known that defects in proteins involved in mitochondrial quality control can cause Parkinson's disease, and there is increasing evidence linking mitochondrial dysfunction, and particularly mitochondrial DNA abnormalities, to neuronal loss in the substantia nigra. Mutations in the catalytic subunit of polymerase gamma are among the most common causes of mitochondrial disease and owing to its role in mitochondrial DNA homeostasis, polymerase gamma defects are often considered a paradigm for mitochondrial diseases generally. Yet, despite this, parkinsonism is uncommon with polymerase gamma defects. In this study, we investigated structural and functional changes in the substantia nigra of 11 patients with polymerase gamma encephalopathy. We characterized the mitochondrial DNA abnormalities and examined the respiratory chain in neurons of the substantia nigra. We also investigated nigrostriatal integrity and function using a combination of post-mortem and in vivo functional studies with dopamine transporter imaging and positron emission tomography. At the cellular level, dopaminergic nigral neurons of patients with polymerase gamma encephalopathy contained a significantly lower copy number of mitochondrial DNA (depletion) and higher levels of deletions than normal control subjects. A selective and progressive complex I deficiency was seen and this was associated with a severe and progressive loss of the dopaminergic neurons of the pars compacta. Dopamine transporter imaging and positron emission tomography showed that the degree of nigral neuronal loss and nigrostriatal depletion were severe and appeared greater even than that seen in idiopathic Parkinson's disease. Despite this, however, none of our patients showed any signs of parkinsonism. The additional presence of both thalamic and cerebellar dysfunction in our patients suggested that these may play a role in counteracting the effects of basal ganglia dysfunction and prevent the development of clinical parkinsonism.

Latencies longer than 3.5 ms after vagus nerve stimulation does not exclude a nonrecurrent inferior laryngeal nerve.

BACKGROUND: It has recently been reported that a signal latency shorter than 3.5 ms after electrical stimulation of the vagus nerve signify a nonrecurrent course of the inferior laryngeal nerve. We present a patient with an ascending nonrecurrent inferior laryngeal nerve. In this patient, the stimulation latency was longer than 3.5 ms. CASE PRESENTATION: A 74-years old female underwent redo surgery due to a right-sided recurrent nodular goitre. The signal latency on electrical stimulation of the vagus nerve at the level of the carotid artery bifurcation was 3.75 ms. Further dissection revealed a nonrecurrent but ascending course of the inferior laryngeal nerve. Caused by the recurrent goitre, the nerve was elongated to about 10 cm resulting in this long latency. CONCLUSION: This case demonstrates that the formerly proposed "3.5 ms rule" for identifying a nonrecurrent course of the inferior laryngeal nerve has exceptions. A longer latency does not necessarily exclude a nonrecurrent laryngeal nerve.

High cardiac background activity limits 99mTc-MIBI radioguided surgery in aortopulmonary window parathyroid adenomas.

BACKGROUND: Radioguided surgery using 99m-Technetium-methoxyisobutylisonitrile (99mTc-MIBI) has been recommended for the surgical treatment of mediastinal parathyroid adenomas. However, high myocardial 99mTc-MIBI uptake may limit the feasibility of radioguided surgery in aortopulmonary window parathyroid adenoma. CASE PRESENTATION: Two female patients aged 72 (#1) and 79 years (#2) with primary hyperparathyroidism caused by parathyroid adenomas in the aortopulmonary window were operated by transsternal radioguided surgery. After intravenous injection of 370 MBq 99mTc-MIBI at start of surgery, the maximum radioactive intensity (as counts per second) was measured over several body regions using a gamma probe before and after removal of the parathyroid adenoma. Relative radioactivity was calculated in relation to the measured ex vivo radioactivity of the adenoma, which was set to 1.0. Both patients were cured by uneventful removal of aortopulmonary window parathyroid adenomas of 4400 (#1) and 985 mg (#2). Biochemical cure was documented by intraoperative measurement of parathyroid hormone as well as follow-up examination. Ex vivo radioactivity over the parathyroid adenomas was 196 (#1) and 855 counts per second (#2). Before parathyroidectomy, relative radioactivity over the aortopulmonary window versus the heart was found at 1.3 versus 2.6 (#1) and 1.8 versus 4.8 (#2). After removal of the adenomas, radioactivity within the aortopulmonary window was only slightly reduced. CONCLUSION: High myocardial uptake of 99mTc-MIBI limits the feasibility of radioguided surgery in aortopulmonary parathyroid adenoma.

Rebooting nuclear medicine specialist education under the COVID-19 pandemic: From plenary lectures to active e-learning.

Despite major reforms of specialist training in the Nordic countries towards concrete learning outcomes and promoting active learning, most specialist courses continue to be based on lectures. We redesigned our mandatory 5-day course in clinical nuclear medicine (NM) that was last held in 2016 towards active learning. Thirty 1-h lectures were replaced with 10 thematic blocks of 3 h each. Each block was taught by a single teacher in a blend of short introductory lectures alternating with small groups of residents reading NM cases from our newly established national case library in diagnostic format. Due to COVID-19, the entire course in 2021 needed to be run on a videoconferencing system rather than in a computer laboratory as had been originally planned. At the end of the course, we conducted the same anonymized survey as in 2016. All 19 course participants responded. 74% fully agreed that the e-course format had been 'good'. One hundred per cent fully agreed that the practical exercises were 'useful' versus 50% in 2016 (p < 0.001). In their free text answers on the merits or downsides of e-learning, 12/12 respondents only mentioned advantages. Our newly established library of anonymized teaching cases within our national health network is an effective tool for organising courses based on active learning. Despite the change towards distance learning enforced by the pandemic, course participants reported the same high levels of satisfaction with active learning in small groups as in the earlier traditional lecture-based course format.

Progressive striatal necrosis associated with anti-NMDA receptor antibodies.

BACKGROUND: We report a case of childhood onset, generalized dystonia due to slowly progressive bilateral striatal necrosis associated with anti-N-methyl-D-aspartate receptor (NMDAR) antibodies. This clinical phenotype has not been previously associated with NMDA receptor autoimmunity. CASE PRESENTATION: An eighteen year old man presented with a history of childhood-onset, progressive generalized dystonia. Clinical examination revealed a pure generalized dystonia with no cognitive or other neurological findings. Magnetic resonance imaging showed bilateral high T2 signal striatal lesions, which were slowly progressive over a period of nine years. New parts of the lesion showed restricted water diffusion suggesting cytotoxic oedema. Positron emission tomography of the brain showed frontal hypermetabolism and cerebellar hypometabolism. Antibodies against the NR1 subunit of the NMDA receptor were detected in the patient's serum and cerebrospinal fluid. There was no neoplasia or preceding infection or vaccination. CONCLUSION: This is the first report of chronic progressive bilateral striatal necrosis associated with anti-NMDAR antibodies. Our findings expand the clinical spectrum of disease associated with anti-NMDAR antibodies and suggest that these should be included in the work-up of dystonia with striatal necrosis.

Is there a role for PET-CT and SPECT-CT in pediatric oncology?

During the last decade, hybrid imaging has revolutionized nuclear medicine. Multimodal camera systems, integrating positron emission tomography (PET) or single photon emission computed tomography (SPECT) with computed tomography (CT) now combine the contrast provided by tumor-avid radioactive drugs with the anatomic precision of CT. While PET-CT to a great extent has replaced single-modality PET in adult oncology, the use of PET-CT in children has been controversial, since even the lowest dose CT protocols adds approximately 2 mSv to the radiation dose of about 4 mSv from the PET-study with F-18-fluorodeoxyglucose (F-18-FDG). The article describes the current techniques used, discusses radiation doses and gives an overview of current indications for PET-CT and SPECT-CT in children. Hybrid imaging with a tumor-avid radioactive drug provides extremely high contrast between tumor and background tissues, while the CT component helps to locate the lesion anatomically. Currently both PET-CT and SPECT-CT play a role in pediatric oncology; PET-CT using F-18-FDG particularly for staging and follow-up of lymphoma and brain cancer, bone and soft tissue sarcomas; SPECT-CT with I-123-metaiodobenzylguanidine (MIBG) for tumors of the sympathetic nervous system such as neuroblastoma and pheochromocytoma while the remaining neuroendocrine tumors are imaged with radioactively labeled somatostatin analogues. To reduce radiation dose, a low-dose CT in combination with ultrasound and/or magnetic resonance imaging for the assessment of anatomy is often preferred.

Thyroid cancer surgery in Germany: an analysis of the nationwide DRG statistics 2005-2006.

PURPOSE: In 2004, a Diagnosis Related Groups (DRG)-based hospital reimbursement system became mandatory in Germany. The aim of this study was to provide nationwide data on the surgery of thyroid cancer by analyzing DRG statistics of the years 2005 and 2006. METHODS: The unit of analysis was hospital admission with a diagnosis of thyroid cancer. We assessed the influence of age, sex and region on the relative frequency of thyroid cancer-related hospitalisations with surgery of the thyroid and we measured the association between hospitalisation rates and incidence rates of thyroid cancer among the Federal States of Germany. RESULTS: Over the period 2005 to 2006, 11,107 thyroid cancer-associated hospitalisations included surgical treatment of the thyroid. The age-standardised DRG-based hospitalisation rates and the corresponding cancer registry-based incidences of thyroid cancer were positively associated. Overall, 68% of the hospitalisations with thyroid surgery included a total thyroidectomy. The percentage of surgery of the thyroid with a total thyroidectomy was nearly identical among men and women, decreased among men aged over 60 and varied considerably by region (minimum, 48% in Saarland; maximum, 78% in Saxony-Anhalt). CONCLUSIONS: Our analyses of DRG statistics provide for the first time representative population-based data of the surgical management of thyroid cancer patients in Germany. Despite an identical health care system all over Germany and existing guidelines for surgical treatment of thyroid cancer, we observed a considerable regional variation in the proportion of total thyroidectomies performed in Germany.

Gastric function in diabetic gastroparesis assessed by ultrasound and scintigraphy.

BACKGROUND: Gastroparesis is a severe diabetes complication characterized by delayed gastric emptying. We examined patients with symptoms of diabetic gastroparesis using gastric emptying scintigraphy and ultrasound drink test. The primary aim was to investigate how ultrasound could provide information about gastric motility features in diabetic gastroparesis. MATERIAL AND METHODS: We prospectively included 58 patients with diabetes (48 type 1) with symptoms of gastroparesis and 30 healthy controls. Patients were examined with ultrasound of the stomach in a seated position after drinking 500 ml low-caloric meat soup, at the same time recording dyspeptic symptoms. The following day, they were examined with gastric emptying scintigraphy, defining gastroparesis as >10% retention after 4 h. KEY RESULTS: We found motility disturbances in the proximal stomach measured by ultrasound in patients with diabetic gastroparesis. A linear mixed effects model including repeated ultrasound measurements revealed a slower decrease of the proximal stomach size in gastroparesis compared to healthy controls (p < 0.01), and the proximal diameter at 20 min was correlated to scintigraphy at 4 h (r = 0.510, p = 0.001). The antrum in patients with diabetic gastroparesis was twice as large compared to healthy controls (p = 0.009), and fasting antral size was correlated to gastric emptying scintigraphy (r = 0.329, p = 0.013). Both diabetes patients with and without gastroparesis had impaired accommodation (p = 0.011). CONCLUSIONS AND INFERENCES: On ultrasound, we found delayed reduction of proximal stomach size and impaired accommodation after a liquid meal in patients with gastroparesis, emphasizing the role of the proximal stomach. Furthermore, we found antral distention in gastroparesis patients.

Enhancing PSMA-PET/CT with intravenous contrast: Improved tracer clearance in the prostate bed.

AIMS: We observed hitherto unreported layering of radioactivity in the bladder on PET/CT in prostate cancer (PC) when combined with contrast-enhanced CT (CECT). This effect facilitates assessment of the prostate bed in PC. METHODS: Among 128 patients imaged with [18F]PSMA-1007, we selected all 8 studies without and 28 studies with CECT. 20 patients also underwent PET/MR. As controls, we chose 20 and 16 males studied with [18F]FDG for extrapelvic disease with and without CECT. Posterior anterior (PA) ratio was calculated as SUVpost/SUVant * 100 % based on maximal standard uptake values (SUV) in 20 mm spheres in the anterior and posterior bladder. Four nuclear physicians scored assessibility of the bladder base on a 3-point Likert scale (3 = optimal, 1 = poor). We acquired serial PET/CT over 4 hours of a flask with layering of 100 ml intravenous contrast agent and 100 ml physiological saline with 40 MBq of [18F]PSMA-1007, while a control flask was shaken at the start of the experiment. RESULTS: Layering of tracer was observed in all PET/CT studies with CE-CT, but not in studies without contrast. Median PA ratios were 44 % (interquartile range 33-62) for [18F]PSMA-1007 and 73 % (52-67) for [18F]FDG, respectively. Intravenous contrast improved assessibility scores in PET of the bladder base, but the effect only reached significance in the PET/MR data. In the in vitro data, radioactivity was retained in the aqueous supernatant over the entire experiment whereas there was no separation of phases in the control flask over time. CONCLUSION: When performing PET combined with CECT, sedimentation of contrast agent in the bladder leads to upward displacement of radioactivity, enhancing clarity of PET images in the posterior bladder and the prostate bed on both PET/CT and PET/MR.

An Open Source Solution for "Hands-on" teaching of PET/CT to Medical Students under the COVID-19 Pandemic.

AIMS: Since 2017, medical students at the University of Bergen were taught PET/CT "hands-on" by viewing PET/CT cases in native format on diagnostic workstations in the hospital. Due to the COVID-19 pandemic, students were barred access. This prompted us to launch and evaluate a new freeware PET/CT viewing system hosted in the university network. METHODS: We asked our students to install the multiplatform Fiji viewer with Beth Israel PET/CT plugin (http://petctviewer.org) on their personal computers and connect to a central image database in the university network based on the public domain orthanc server (https://orthanc-server.com). At the end of course, we conducted an anonymous student survey. RESULTS: The new system was online within eight days, including regulatory approval. All 76 students (100 %) in the fifth year completed their course work, reading five anonymized PET/CT cases as planned. 41 (53 %) students answered the survey. Fiji was challenging to install with a mean score of 1.8 on a 5-point Likert scale (5 = easy, 1 = difficult). Fiji was more difficult to use (score 3.0) than the previously used diagnostic workstations in the hospital (score 4.1; p < 0.001, paired t-test). Despite the technical challenge, 47 % of students reported having learnt much (scores 4 and 5); only 11 % were negative (scores 1 and 2). 51 % found the PET/CT tasks engaging (scores 4 and 5) while 20 % and 5 % returned scores 2 and 1, respectively. CONCLUSION: Despite the initial technical challenge, "hands-on" learning of PET/CT based on the freeware Fiji/orthanc PET/CT-viewer was associated with a high degree of student satisfaction. We plan to continue running the system to give students permanent access to PET/CT cases in native format regardless of time or location.