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result(s) for
"Well Lennart"
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Phenotyping spinal abnormalities in patients with Neurofibromatosis type 1 using whole-body MRI
2021
Neurofibromatosis Type 1 (NF1) has been reported to be associated with a variety of spinal abnormalities. The purpose of this study was to quantify the prevalence of spinal abnormalities in a collective of NF1 patients that is representative for the general NF1 population, to associate the co-appearance of spinal abnormalities with both NF1 and clinical symptoms and to investigate if different mutations of the
NF1
gene affect the prevalence of these abnormalities. Retrospectively, 275 patients with NF1 and an age- and sex-matched collective of 262 patients were analyzed. The prevalence of spinal abnormalities was recorded. Mutational analysis of the
NF1
gene was obtained in 235 NF1 patients. Associations between spinal abnormalities, clinical symptoms and genotype were investigated by binary logistic regression analysis. Prevalence of all spinal abnormalities was higher in NF1 patients than in the control group. Six characteristics of spinal abnormalities were significantly associated with NF1 (all
p
< 0.05). An influence of scalloping on scoliosis (OR 3.01;
p
= 0.002); of meningoceles (OR 7.63) and neuroforaminal tumors (OR 2.96) on scalloping, and of dural ectasia on neuroforaminal tumors (OR 1.93) was identified. Backpain and loss of motor function were associated with neuroforaminal tumors, spinal tumors and scalloping of vertebral bodies (all
p
< 0.05). Specific mutations of the
NF1
gene were not relevantly associated with the development of spinal abnormalities. These findings can aid clinicians to improve clinical care of NF1 patients by creating awareness for co-appearences of specific spinal abnormalities and associated symptoms.
Journal Article
Genotype-phenotype correlation in neurofibromatosis type-1: NF1 whole gene deletions lead to high tumor-burden and increased tumor-growth
by
Döbel, Kimberly
,
Farschtschi, Said
,
Bannas, Peter
in
Analysis
,
Automation
,
Biology and Life Sciences
2021
Neurofibromatosis type-1 (NF1) patients suffer from cutaneous and subcutaneous neurofibromas (CNF) and large plexiform neurofibromas (PNF). Whole gene deletions of the NF1 gene can cause a more severe phenotype compared to smaller intragenic changes. Two distinct groups of NF1 whole gene deletions are type-1 deletions and atypical deletions. Our aim was to assess volumes and averaged annual growth-rates of CNF and PNF in patients with NF1 whole gene deletions and to compare these with NF1 patients without large deletions of the NF1 gene. We retrospectively evaluated 140 whole-body MR examinations of 38 patients with NF1 whole gene deletions (type-1 group: n = 27/atypical group n = 11) and an age- and sex matched collective of 38 NF1-patients. Age-dependent subgroups were created (0–18 vs >18 years). Sixty-four patients received follow-up MRI examinations ( NF1 whole gene deletion n = 32/control group n = 32). Whole-body tumor-volumes were semi-automatically assessed (MedX, V3.42). Tumor volumes and averaged annual growth-rates were compared. Median tumor-burden was significantly higher in the type-1 group (418ml; IQR 77 – 950ml, p = 0.012) but not in the atypical group (356ml;IQR 140–1190ml, p = 0.099) when compared to the controls (49ml; IQR 11–691ml). Averaged annual growth rates were significantly higher in both the type-1 group (14%/year; IQR 45–36%/year, p = 0.004) and atypical group (11%/year; IQR 5–23%/year, p = 0.014) compared to the controls (4%/year; IQR1–8%/year). Averaged annual growth rates were significantly higher in pediatric patients with type-1 deletions (21%/year) compared with adult patients (8%/year, p = 0.014) and also compared with pediatric patients without large deletions of the NF1 gene (3.3%/year, p = 0.0015). NF1 whole gene deletions cause a more severe phenotype of NF1 with higher tumor burden and higher growth-rates compared to NF1 patients without large deletions of the NF1 gene. In particular, pediatric patients with type-1 deletions display a pronounced tumor growth.
Journal Article
Response to trametinib treatment in progressive pediatric low-grade glioma patients
2020
IntroductionA hallmark of pediatric low-grade glioma (pLGG) is aberrant signaling of the mitogen activated protein kinase (MAPK) pathway. Hence, inhibition of MAPK signaling using small molecule inhibitors such as MEK inhibitors (MEKi) may be a promising strategy.MethodsIn this multi-center retrospective centrally reviewed study, we analyzed 18 patients treated with the MEKi trametinib for progressive pLGG as an individual treatment decision between 2015 and 2019. We have investigated radiological response as per central radiology review, molecular classification and investigator observed toxicity.ResultsWe observed 6 partial responses (PR), 2 minor responses (MR), and 10 stable diseases (SD) as best overall responses. Disease control rate (DCR) was 100% under therapy. Responses were observed in KIAA1549:BRAF- as well as neurofibromatosis type 1 (NF1)-driven tumors. Median treatment time was 12.5 months (range: 2 to 27 months). Progressive disease was observed in three patients after cessation of trametinib treatment within a median time of 3 (2–4) months. Therapy related adverse events occurred in 16/18 patients (89%). Eight of 18 patients (44%) experienced severe adverse events (CTCAE III and/or IV; most commonly skin rash and paronychia) requiring dose reduction in 6/18 patients (33%), and discontinuation of treatment in 2/18 patients (11%).ConclusionsTrametinib was an active and feasible treatment for progressive pLGG leading to disease control in all patients. However, treatment related toxicity interfered with treatment in individual patients, and disease control after MEKi withdrawal was not sustained in a fraction of patients. Our data support in-class efficacy of MEKi in pLGGs and necessity for upfront randomized testing of trametinib against current standard chemotherapy regimens.
Journal Article
Whole-body MRI-based long-term evaluation of pediatric NF1 patients without initial tumor burden with evidence of newly developed peripheral nerve sheath tumors
2024
Background
Patients with neurofibromatosis type 1 (NF1) can develop plexiform neurofibromas (PN). Large tumor burden is a predictor for the development of malignant peripheral nerve sheath tumors. Whole-body magnetic resonance imaging (WB-MRI) is the recommended imaging method for the evaluation of PN. WB-MRI is recommended for NF1 patients at transition from adolescence to adulthood. In the absence of internal PN further follow-up WB-MRI is not considered necessary. PN are often detected in early childhood, leading to the assumption that they may be congenital lesions. It remains unclear whether this invariably applies to all patients or whether patients who initially displayed no tumors can still develop PN over time. Therefore, we retrospectively reviewed WB-MRI scans of pediatric patients with NF1 without initial tumor burden and compared these with long-term follow-up scans for presence of newly developed PN.
Methods
We retrospectively reviewed WB-MRI scans of 17 NF1-children (twelve male; median age at initial scan: 9 [IQR 6.1–11.9] years) who initially displayed no PN. MRI scans with a follow-up interval of at least 6 years (median follow-up interval: 9 [IQR 5.6–12.4] years) were reviewed in consensus by two radiologists regarding the development of new PN over time.
Results
New PN were identified in two out of 17 children without initial tumor burden in follow-up examinations. One of these two patients developed two larger distinct PN of 4.5 cm on the right upper arm and of 2.5 cm on the left thoracic wall between the age of ten and twelve. The second child developed multiple smaller PN along the major peripheral nerves between the age of eleven and 16. In addition, 15 of the children without initial tumor burden did not develop any distinct tumors for a period of at least 6 years.
Conclusion
Our results indicate that PN can be newly detected in pediatric patients over time, even if no PN were detected on initial MRI scans. Therefore, it seems reasonable to perform at least a second MRI in pediatric NF1 patients at transition to adulthood, even if they did not display any tumor burden on initial MRI, and when the MRI was performed significantly under the age of 18. With this approach, tumors that may have developed between scans can be detected and patients at risk for complications can be identified.
Journal Article
Artificial intelligence-based tools for precision diagnosis and treatment of neurofibromatosis type 1 associated peripheral and central glial tumors
2025
Modern Artificial Intelligence (AI) has demonstrated its effectiveness by achieving human-level performance in various complex tasks, including the biomedical field. Cancer research, adapting to a fast-changing world, is leveraging AI as a promising framework to better understand tumor development. Moreover, current AI methods can help predict more suitable and personalized treatment strategies for specific types of tumors. We explored AI methods applied to Neurofibromatosis Type 1, focusing on glial tumors. Additionally, we have reviewed all publicly available datasets to date. Discussion of future challenges is highly desirable since Neurofibromatosis Type 1 is one of the most common hereditary tumor syndromes and is associated with an increased rate of glial tumors as well as a reduced life expectancy due to malignancy.
Journal Article
Radiation dose reduction during adrenal vein sampling using a new angiographic imaging technology
by
Bannas, Peter
,
Adam, Gerhard
,
Lenz, Alexander
in
631/1647/245/1847
,
692/163/2743
,
692/698/1460
2022
To compare the patient radiation doses during angiographic selective adrenal vein sampling (AVS) before and after an imaging technology upgrade. In this retrospective single-center-study, cumulative air kerma (AK), cumulative dose area product (DAP), fluoroscopy time and contrast agent dosage were recorded from 70 patients during AVS. 35 procedures were performed before and 35 after an imaging processing technology upgrade. Mean values were calculated and compared using an unpaired student’s t-test. DSA image quality was assessed independently by two blinded readers using a four-point Likert scale (1 = poor; 4 = excellent) and compared using Wilcoxon signed-rank test. After the technology upgrade we observed a significant reduction of 35% in AK (1.7 ± 0.7 vs. 1.1 ± 0.7 Gy, p = 0.01) and a significant reduction of 28% in DAP (235.1 ± 113 vs. 170.1 ± 94 Gy*cm
2
, p = 0.01) in comparison to procedures before the upgrade. There were no significant differences between the number of exposure frames (143 ± 86 vs. 132 ± 61 frames, p = 0.53), fluoroscopy time (42 ± 23 vs. 36 ± 18 min, p = 0.22), or the amount of contrast medium used (179.5 ± 84 vs. 198.1 ± 109 ml, p = 0.41). There was also no significant difference regarding image quality (3 (2–4) vs. 3 (2–4), p = 0.67). The angiographic imaging technology upgrade significantly decreases the radiation dose during adrenal vein sampling without increasing time of fluoroscopy or contrast volume and without compromising image quality.
Journal Article
Non-contrast free-breathing 2D CINE compressed SENSE T1-TFE cardiovascular MRI at 3T in sedated young children for assessment of congenital heart disease
by
Zhang, Shuo
,
Bannas, Peter
,
Stark, Maria
in
Biology and Life Sciences
,
Care and treatment
,
Children
2024
Cardiac MRI is a crucial tool for assessing congenital heart disease (CHD). However, its application remains challenging in young children when performed at 3T. The aim of this retrospective single center study was to compare a non-contrast free-breathing 2D CINE T1-weighted TFE-sequence with compressed sensing (FB 2D CINE CS T1-TFE) with 3D imaging for diagnostic accuracy of CHD, image quality, and vessel diameter measurements in sedated young children. FB 2D CINE CS T1-TFE was compared with a 3D non-contrast whole-heart sequence (3D WH) and 3D contrast-enhanced MR angiography (3D CE-MRA) at 3T in 37 CHD patients (20♂, 1.5±1.4 years). Two radiologists independently assessed image quality, type of CHD, and diagnostic confidence. Diameters and measures of contrast and sharpness of the aorta and pulmonary vessels were determined. A non-parametric multi-factorial approach was used to estimate diagnostic accuracy for the diagnosis of CHD. Linear mixed models were calculated to compare contrast and vessel sharpness. Krippendorff’s alpha was determined to quantify vessel diameter agreement. FB 2D CINE CS T1-TFE was rated superior regarding image quality, diagnostic confidence, and diagnostic sensitivity for both intra- and extracardiac pathologies compared to 3D WH and 3D CE-MRA (all p<0.05). FB 2D CINE CS T1-TFE showed superior contrast and vessel sharpness (p<0.001) resulting in the highest proportion of measurable vessels (740/740; 100%), compared to 3D WH (530/620; 85.5%) and 3D CE-MRA (540/560; 96.4%). Regarding vessel diameter measurements, FB 2D CINE CS T1-TFE revealed the closest inter-reader agreement (Krippendorff’s alpha: 0.94–0.96; 3D WH: 0.78–0.94; 3D CE-MRA: 0.76–0.93). FB 2D CINE CS T1-TFE demonstrates robustness at 3T and delivers high-quality diagnostic results to assess CHD in sedated young children. Its ability to function without contrast injection and respiratory compensation enhances ease of use and could encourage widespread adoption in clinical practice.
Journal Article
The effect of pregnancy on growth-dynamics of neurofibromas in Neurofibromatosis type 1
by
Jaeger, Anna
,
Farschtschi, Said
,
Kehrer-Sawatzki, Hildegard
in
Comparative analysis
,
Diagnostic imaging
,
Estrogens
2020
Patients with Neurofibromatosis type 1 (NF1) develop plexiform neurofibromas (PNF) and cutaneous neurofibromas. These tumors are a major cause of the patient's morbidity and mortality. An influence of estrogen and progesterone on tumor growth has been suggested but reports on growth or malignant transformation of tumors during pregnancy remain anecdotal. The purpose of this study was to quantify growth of cutaneous and plexiform neurofibromas in NF1 patients during pregnancy, and to assess the onset of NF1 related symptoms.
Retrospectively, 13 mothers with NF1 were included and compared to nullipara, nulligravida, age-matched women with NF1. All women received whole-body magnetic resonance imaging (MRI) before and after pregnancy or after a matched time period. Presence of plexiform and cutaneous neurofibromas was evaluated. PNF were subjected to semi-automated volumetry (MedX). The sum of the longest diameters (SLD) of representative cutaneous neurofibromas was determined for both groups. Clinical symptoms and subjective tumor growth were assessed.
PNF were identified in 12/26 women (46.2%). Follow up showed neither new PNF nor a significant difference in growth rate (median tumor-growth/year: pregnant group-0.38% (IQR -1.1-5.4%) vs control group 3.59% (IQR -2.1-5.5%; P = 0.69). Malignant transformation of PNF was not observed. There was a significant growth of cutaneous neurofibromas in both groups (median SLD increase: pregnant group 17mm; P = 0.0026 / control group 12mm; P = 0.0004) The difference in increase of SLD was not significant (P = 0.48). Singular cutaneous neurofibromas in the pregnant group displayed high levels of tumor growth (>20%/year). NF1-associated symptoms and subjective tumor growth were not significantly increased in pregnant patients.
Growth of plexiform and cutaneous neurofibromas in pregnant patients is not significantly different compared to non-pregnant patients. Cutaneous neurofibromas show a significant increase in growth over time in both, pregnant and non-pregnant patients and NF1 related clinical symptoms do not significantly aggravate during the course of pregnancy.
Journal Article
Blunt traumatic right coronary artery dissection presenting with second-degree atrioventricular block and late-onset severe cardiogenic shock
by
Cramer, Christopher
,
Warncke, Malte Lennart
,
Kluge, Stefan
in
Abdomen
,
Acute myocardial infarction
,
Analysis
2022
Background
Blunt chest injury may induce several cardiovascular traumata, requiring immediate care. Right coronary artery dissection (RCA) is an extremely rare sequela in this setting and is associated with high mortality, if it remains undiagnosed.
Case presentation
We present the case of an RCA dissection after blunt chest trauma in a 16-year-old patient, who initially presented with a second-degree atrioventricular block as solitary manifestation on admission. Typical electrocardiographic findings, such as ST segmental changes or pathological Q waves were absent. Serial echocardiograms excluded segmental motion abnormalities, pericardial effusion or right ventricular strain. Nevertheless, a complementary computed tomography coronary angiography revealed this potentially lethal condition several hours later. The patient underwent an emergency surgical myocardial revascularization under the circulatory support of veno-arterial extracorporeal membrane oxygenation and suffered a prolonged right ventricular insufficiency with severe late-onset cardiogenic shock, due to an extensive myocardial infarction of the inferoseptal ventricular wall.
Conclusion
Right coronary artery dissection after high-speed blunt chest injury constitutes a diagnostic challenge, especially in the absence of typical electrocardiographic and echocardiographic findings in young patients. This condition may dramatically deteriorate in time, leading to severe cardiogenic shock and life-threatening arrhythmias.
Journal Article