Diffuse idiopathic skeletal hyperostosis: Etiology and clinical relevance

Diffuse idiopathic skeletal hyperostosis (DISH) is a systemic bone-forming condition characterized by the presence of at least three bony bridges at the anterolateral spine. The aim of this review was to address the present state of pathophysiological knowledge, the clinical relevance, and diagnosis of DISH. The pathogenesis of DISH is currently unknown. The presence of DISH has been associated with older age, male sex, obesity, hypertension, atherosclerosis, and diabetes mellitus. Because the new bone forms mainly at entheseal sites, local fibroblasts, chondrocytes, collagen fibers, and calcified matrix are probably influenced by genetic, vascular, metabolic, and mechanical factors. Diagnosing the presence of DISH is of clinical importance, because the risk of a spinal fracture increases and associations with the metabolic syndrome, coronary and aortic disease, and respiratory effects are strong. Unravelling the pathogenesis of DISH can impact the field of regenerative medicine and bone tissue regeneration

Pseudohypoparathyroidism mimicking cervical diffuse idiopathic skeletal hyperostosis with dysphagia: A case report and literature review

Dysphagia due to extensive ossification at anterior segments of the cervical spine is a rare occurrence and is usually attributable to diffuse idiopathic skeletal hyperostosis (DISH). We present the case of a 74-year-old female with dysphagia most likely due to ossification in pseudohypoparathyroidism type 1a (PHP1a). PHP1a is a rare, autosomal dominant disorder caused by mutations in the GNAS1 gene. Our patient had characteristic phenotype features of PHP1a, also known as Albright's hereditary osteodystrophy (AHO), which was diagnosed without genetic confirmation. She was conservatively treated with dietary measures and observation, and reported persisting symptoms of dysphagia at six-month follow-up. This is the first case to describe dysphagia in PHP1a with a similar presentation to DISH

Real-time myocardial landmark tracking for MRI-guided cardiac radio-ablation using Gaussian Processes

The high speed of cardiorespiratory motion introduces a unique challenge for cardiac stereotactic radio-ablation (STAR) treatments with the MR-linac. Such treatments require tracking myocardial landmarks with a maximum latency of 100 ms, which includes the acquisition of the required data. The aim of this study is to present a new method that allows to track myocardial landmarks from few readouts of MRI data, thereby achieving a latency sufficient for STAR treatments. We present a tracking framework that requires only few readouts of k-space data as input, which can be acquired at least an order of magnitude faster than MR-images. Combined with the real-time tracking speed of a probabilistic machine learning framework called Gaussian Processes, this allows to track myocardial landmarks with a sufficiently low latency for cardiac STAR guidance, including both the acquisition of required data, and the tracking inference. The framework is demonstrated in 2D on a motion phantom, and in vivo on volunteers and a ventricular tachycardia (arrhythmia) patient. Moreover, the feasibility of an extension to 3D was demonstrated by in silico 3D experiments with a digital motion phantom. The framework was compared with template matching - a reference, image-based, method - and linear regression methods. Results indicate an order of magnitude lower total latency (<10 ms) for the proposed framework in comparison with alternative methods. The root-mean-square-distances and mean end-point-distance with the reference tracking method was less than 0.8 mm for all experiments, showing excellent (sub-voxel) agreement. The high accuracy in combination with a total latency of less than 10 ms - including data acquisition and processing - make the proposed method a suitable candidate for tracking during STAR treatments

Gene expression profiling of bronchial brushes is associated with the level of emphysema measured by computed tomography-based parametric response mapping

Parametric response mapping (PRM) is a computed tomography (CT)-based method to phenotype patients with chronic obstructive pulmonary disease (COPD). It is capable of differentiating emphysema-related air trapping with nonemphysematous air trapping (small airway disease), which helps to identify the extent and localization of the disease. Most studies evaluating the gene expression in smokers and COPD patients related this to spirometric measurements, but none have investigated the relationship with CT-based measurements of lung structure. The current study aimed to examine gene expression profiles of brushed bronchial epithelial cells in association with the PRM-defined CT-based measurements of emphysema (PRM(Emph)) and small airway disease (PRM(fSAD)). Using the Top Institute Pharma (TIP) study cohort (COPD = 12 and asymptomatic smokers = 32), we identified a gene expression signature of bronchial brushings, which was associated with PRM(Emph) in the lungs. One hundred thirty-three genes were identified to be associated with PRM(Emph). Among the most significantly associated genes, CXCL11 is a potent chemokine involved with CD8(+) T cell activation during inflammation in COPD, indicating that it may play an essential role in the development of emphysema. The PRM(Emph) signature was then replicated in two independent data sets. Pathway analysis showed that the PRM(Emph) signature is associated with proinflammatory and notch signaling pathways. Together these findings indicate that airway epithelium may play a role in the development of emphysema and/or may act as a biomarker for the presence of emphysema. In contrast, its role in relation to functional small airways disease is less clear

Application of three-dimensional computed tomography imaging and reconstructive techniques in lung surgery: A mini-review

BACKGROUND: Pulmonary surgery is an innovative discipline with increasing demands for minimally invasive techniques in complicated anatomical resections, warranting adequate preoperative imaging of relevant surgical anatomy to ensure safe and radical resection of target lesions. Over the recent years, the emergence of imaging techniques enabling three-dimensional reconstruction has exerted promising influence on pulmonary surgery, facilitating optimal surgical planning and easier identification of the spatial relationship between bronchovascular structures in the individual patient and aiding the safe resection of target pulmonary lesions. The goal of this mini-review is to provide an overview of three-dimensional computed tomography imaging within pulmonary surgery. METHODS: The authors performed a targeted qualitative review of the literature to identify current trends and to provide better understanding of three-dimensional reconstruction within the boundaries of pulmonary surgery. RESULTS: Three-dimensional reconstructive techniques can be used for resectability assessment, identification of surgically relevant interindividual anatomic variance and may improve perioperative outcomes. DISCUSSION: Three-dimensional reconstruction using computed tomography imaging improves surgical planning and there is evidence that it results in shorter operative times, less intraoperative blood loss and lower rates of surgical conversion, as it can be applied both pre- and intraoperatively

Predictors for progressive fibrosis in patients with connective tissue disease associated interstitial lung diseases

Background: Connective tissue disease associated interstitial lung disease (CTD-ILD) is associated with decreased quality of life and high mortality risk. Outcome and treatment response is unpredictable. This study aimed to identify clinical predictors for CTD-ILD with poor outcome. Methods: We performed a retrospective single centre cohort study in outpatients with CTD-ILD seen between 2004 and 2018. Clinical and biochemical data, pulmonary function tests (PFT) and high-resolution computed tomography (HRCT) results were analysed. Overall survival and progressive fibrosing ILD (PF-ILD, defined as a significant deterioration of PFT or HRCT) after two years of follow-up were assessed. Results: In total, 150 patients with CTD-ILD were included. Thirty (20%) deaths occurred during a median follow-up of 40 months (IQR 27.3–60.8), which were attributed to pulmonary infection in six (4%), respiratory failure due to PF-ILD in ten (7%) and due to other causes in fourteen patients. PF-ILD occurred in 76 (50.7%) patients and was associated with poor overall survival (adjusted HR 5.73, 95%CI 1.17–28.11). Age, smoking, C-reactive protein, and steroid-use were independently associated with increased mortality risk as well. Furthermore, patients with diabetes mellitus (adjusted OR 4.52, 95%CI 1.10–18.51), steroid-use (adjusted OR 2.26, 95%CI 1.04–4.93), and a fibrotic HRCT pattern at baseline (adjusted OR 3.11, 95%CI 1.15–8.38) had a higher risk of PF-ILD. Conclusion: PF-ILD is associated with increased mortality in patients with CTD-ILD. Patients with a fibrotic HRCT pattern at baseline, diabetes mellitus and steroid-use have a higher risk of developing PF-ILD

Diffuse idiopathic skeletal hyperostosis of the cervical spine causing dysphagia and airway obstruction: an updated systematic review

BACKGROUND AND CONTEXT: Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by growing ossifications of spinal entheses and tendons, which may cause trachea and esophagus compression when located anteriorly in the cervical spine. PURPOSE: Our previous systematic review on the epidemiological and clinical knowledge of dysphagia and airway obstruction caused by cervical DISH was updated, with a focus on (surgical) treatment and outcomes. STUDY DESIGN: A systematic review of the literature was performed. METHODS: Publications in Medline and EMBASE from July 2010 to June 2021 were searched. Two investigators performed data extraction and study specific quality assessment. RESULTS: A total of 138 articles (112 case reports and 26 case series) were included, describing 419 patients with dysphagia and/or airway obstruction. The mean age of the patient group was 67.3 years (range: 35–91 years), and 85.4% was male. An evident increase of published cases was observed within the last decade. Surgical treatment was chosen for 66% of patients with the anterolateral approach most commonly used. The total complication rate after surgery was 22.1%, with 12.7% occurring within 1 month after intervention. Improvement of dysphagia was observed in 95.5% of operated patients. After a mean follow-up of 3.7 years (range: 0.4–9.0 years), dysphagia recurred in 12 surgically treated patients (4%), of which five patients had osteophyte regrowth. CONCLUSIONS: The number of published cases of dysphagia in patients with DISH has doubled in the last decade compared to our previous review. Yet, randomized studies or guidelines on the treatment or prevention on recurrence are lacking. Surgical treatment is effective and has low (major) complication rates. Common trends established across the cases in our study may help improve our understanding and management of dysphagia and airway obstruction in cervical DISH

Low-dose CT measurements of airway dimensions and emphysema associated with airflow limitation in heavy smokers:a cross sectional study

Background: Increased airway wall thickness (AWT) and parenchymal lung destruction both contribute to airflow limitation. Advances in computed tomography (CT) post-processing imaging allow to quantify these features. The aim of this Dutch population study is to assess the relationships between AWT, lung function, emphysema and respiratory symptoms.Methods: AWT and emphysema were assessed by low-dose CT in 500 male heavy smokers, randomly selected from a lung cancer screening population. AWT was measured in each lung lobe in cross-sectionally reformatted images with an automated imaging program at locations with an internal diameter of 3.5 mm, and validated in smaller cohorts of patients. The 15th percentile method (Perc15) was used to assess the severity of emphysema. Information about respiratory symptoms and smoking behavior was collected by questionnaires and lung function by spirometry.Results: Median AWT in airways with an internal diameter of 3.5 mm (AWT(3.5)) was 0.57 (0.44 - 0.74) mm. Median AWT in subjects without symptoms was 0.52 (0.41-0.66) and in those with dyspnea and/or wheezing 0.65 (0.52-0.81) mm (pConclusions: Post processing standardization of airway wall measurements provides a reliable and useful method to assess airway wall thickness. Increased airway wall thickness contributes more to airflow limitation than emphysema in a smoking male population even after adjustment for smoking behavior.</p

On the feasibility of cardiac substructure sparing in magnetic resonance imaging guided stereotactic lung radiotherapy

Background: Lung stereotactic body radiotherapy (SBRT) has proven an effective treatment for medically inoperable lung tumors, even for (ultra-)central tumors. Recently, there has been growing interest in radiation-induced cardiac toxicity in lung radiotherapy. More specifically, dose to cardiac (sub-)structures (CS) was found to correlate with survival after radiotherapy. Purpose: Our goal is first, to investigate the percentage of patients who require CS sparing in an magnetic resonance imaging guided lung SBRT workflow, and second, to quantify how successful implementation of cardiac sparing would be. Methods: The patient cohort consists of 34 patients with stage II–IV lung cancer who were treated with SBRT between 2017 and 2020. A mid-position computed tomography (CT) image was used to create treatment plans for the 1.5 T Unity MR-linac (Elekta AB, Stockholm, Sweden) following clinical templates. Under guidance of a cardio-thoracic radiologist, 11 CS were contoured manually for each patient. Dose constraints for five CS were extracted from the literature. Patients were stratified according to their need for cardiac sparing depending on the CS dose in their non-CS constrained MR-linac treatment plans. Cardiac sparing treatment plans (CSPs) were then created and dosimetrically compared with their non-CS constrained treatment plan counterparts. CSPs complied with the departmental constraints and were considered successful when fulfilling all CS constraints, and partially successful if some CS constraints could be fulfilled. Predictors for the need for and feasibility of cardiac sparing were explored, specifically planning target volume (PTV) size, cranio-caudal (CC) distance, 3D distance, and in-field overlap volume histograms (iOVH). Results: 47% of the patients (16 out of 34) were in need of cardiac sparing. A successful CSP could be created for 62.5% (10 out of 16) of these patients. Partially successful CSPs still complied with two to four CS constraints. No significant difference in dose to organs at risk (OARs) or targets was identified between CSPs and the corresponding non-CS constrained MR-linac plans. The need for cardiac sparing was found to correlate with distance in the CC direction between target and all of the individual CS (Mann–Whitney U-test p-values <10 −6). iOVHs revealed that complying with dose constraints for CS is primarily determined by in-plane distance and secondarily by PTV size. Conclusion: We demonstrated that CS can be successfully spared in lung SBRT on the MR-linac for most of this patient cohort, without compromising doses to the tumor or to other OARs. CC distance between the target and CS can be used to predict the need for cardiac sparing. iOVHs, in combination with PTV size, can be used to predict if cardiac sparing will be successful for all constrained CS except the left ventricle