Clinical trials

BACKGROUND Acute appendicitis (AA) in an early stage is difficult to distinguish from other (self-limiting) causes of acute abdominal pain (e.g. constipation and gastroenteritis), resulting in missing 19% of children with AA at first presentation in primary care and 70% of non-AA cases among referrals. OBJECTIVE To evaluate the impact of the use of a diagnostic strategy for acute appendicitis (AA), which consists of a clinical prediction rule (cPR) including C-reactive protein point-of-care test (CRP POCT), on referral efficiency in children with acute abdominal pain in primary care, as compared to usual care. STUDY DESIGN This is a cluster randomized controlled trial in primary care with a process evaluation. GPs in the intervention group will use an externally validated cPR based on symptoms and signs selectively followed by a CRP POCT in the medium risk group. GPs from general practices allocated to the control group will provide care and diagnosis as usual, i.e. following recommendations of the Dutch College of GPs guideline 'abdominal pain in children'. STUDY POPULATION Children aged 4 to 18 years presenting to their general practitioner (GP) with acute abdominal pain. OUTCOME MEASURES Primary outcome: referral efficiency (proportion non-referrals in non-AA patients during 30 days follow-up). Secondary outcomes: safety (proportion of referrals in AA patients during the first consultation or planned reassessment), proportion of children with CRP-POCT, proportion of children with planned reassessment, child anxiety, parent or child satisfaction, quality of life, and costs.

The aim of the data collection is to create an advanced reliable method to remotely monitor patient on chronic home non-invasive ventilation (NIV), both regarding ventilatory efficacy and patient comfort, both in the hospital and at home by assessing gas exchange, lung mechanics and the interaction between the patient and the ventilator. For this purpose, we will set-up of databank of synchronously acquired datasets of already standard care monitored parameters during NIV (transcutaneous monitoring of gas exchange; ventilator data including data on PVA), and newly non-invasively acquired data on patient effort (EMG, patient ratings) and lung (hyper)inflation (EIT), during the set-up and follow-up of standard care chronic NIV.

Rationale: Neonatal hyperbilirubinemia is highly prevalent in very preterm infants born \<30 weeks. Since 2008, uniform Dutch phototherapy thresholds for preterm infants have been used nationwide, largely based on consensus. Consequently, \>80% of very preterm infants receive phototherapy for several days, accompanied by repeated blood sampling and reduced opportunities for skin-to-skin care. The corresponding UK National Institute for Health and Care Excellence (NICE) guideline applies higher (less strict) thresholds, which may reduce overtreatment, but comparative safety for very preterm infants has not been established in a randomized trial. The investigators hypothesize that using NICE thresholds is non-inferior to Dutch thresholds for survival without neurodevelopmental impairment (NDI) at two years' corrected age, while reducing treatment burden. Objective: Primary: To determine whether initiating phototherapy according to NICE thresholds is non-inferior to Dutch thresholds with regard to survival without NDI at two years' corrected age in infants born \<30 weeks of gestation. Secondary: To compare phototherapy exposure (incidence, duration and cumulative exposure) and monitoring burden (e.g., number of bilirubin blood samples, temperature instability, biomarkers of oxidative stress (subpopulation)), and to evaluate parent-infant outcomes (skin-to-skin contact time, parental stress/satisfaction), and nursing workload (time dedicated to bilirubin-related care). Study design: Nationwide multicenter, parallel-group, open-label randomized non-inferiority trial with 1:1 allocation, stratified by center and gestational age category (\<28 weeks and ≥28 weeks). Follow-up continues to the routine neurodevelopmental assessment at two years' corrected age. Planned project duration: 36 months. Study population: Very preterm infants born \<30+0 weeks of gestation, admitted to a participating Dutch NICU within 24 hours after birth. Intervention: Bilirubin monitoring and phototherapy according to one of two threshold strategies: (1) current Dutch phototherapy thresholds (control) or (2) thresholds from the UK NICE guideline (intervention). Phototherapy is delivered using standard NICU devices. Main study parameters/endpoints: Primary endpoint: survival without NDI at two years' corrected age. NDI is defined as Bayley Scales of Infant and Toddler Development, fourth Edition, Dutch Version (BSID-IV-NL) cognitive and/or motor composite score \<85 and/or hearing impairment and/or visual impairment. Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Both strategies reflect accepted standards of care with routine bilirubin monitoring. Incremental burden consists mainly of additional registration (phototherapy use, bilirubin sampling, skin-to-skin contact, temperature instability), parental questionnaires and, in selected centers, collection of stress-related biomarkers from urine, feces, or waste material from routine blood samples to explore the physiological impact of phototherapy. No biobanking for future unspecified research is planned. The investigators will also use routinely collected and stored monitor data to assess sleep (sleep-wake states and sleep fragmentation) in a subset of infants. Neurodevelopmental follow-up at two years corrected age is routine care in Dutch NICUs. Bilirubin levels above thresholds in both groups will be mitigated by routine monitoring and management according to this study protocol. The study is group-related because bilirubin management and potential neurotoxicity thresholds are specific to very preterm infants.

This is a nationwide, multicenter, registry-based prospective cohort study to assess real-world effectiveness of treatment with a pembrolizumab containing regimen in persistent, recurrent, or metastatic cervical cancer. Patients in the observation cohort continue treatment according to standard of care. In the discontinuation cohort, patients discontinue their maintenance treatment with pembrolizumab (with or without discontinuation of bevacizumab). Patients may choose to discontinue pembrolizumab prematurely (with or without discontinuation of bevacizumab) if they achieve a confirmed CR or a confirmed PR to treatment, or on patient's request or due to toxicity. If an eligible patient chooses not to discontinue treatment early they will remain in the observation cohort. The duration of the trial for the individual patient will be until two years from the start of treatment. Survival follow-up will continue for a maximum of 10 years

Rationale: In the Netherlands, traumatic brain injury (TBI) is one of the most frequent neurological diseases and one of the leading causes of disability. Presumably, about half of the total Dutch population will get a TBI during their lifetime. The majority, about 85%, of patients suffers from a mild TBI (mTBI). The incidence of mTBI is estimated at 68,000 patients each year, but this is an underestimation as patients seen at the general practitioner's offices are not taken into account. In general, the prognosis of mTBI is relatively good, however more than 70% of patient still have one or more post-traumatic complaints at six months post-injury influencing resumption of daily (social) activities and return to work/study. Considering the high annual incidence of mTBI the number of patients with incomplete recovery has high social impact accompanied with excessive health care related costs. Post-traumatic complaints in the chronic phase postinjury are considered therapy resistant and so far no evidence based treatment is available. Hence, the most appropriate strategy is to prevent complaints present in the (sub)acute phase after injury to become persistent to improve functional outcome and quality of life. Objective: The main aim of this study is to improve early care for patients suffering from post-traumatic complaints after mTBI through the development of effective symptom-guided tailored interventions. Nowadays, no effective therapy is available and care-as-usual consists of a wait-and-see policy. Early therapy will reduce posttraumatic complaints and facilitate earlier return to daily activities and work or study, consequently quality of life will be improved as well. This in turn will result in less healthcare consumption and lower societal costs. Study design: The investigators propose a prospective three-arm multicenter open randomized controlled trial (RCT), randomizing participants between two interventions and care as usual. The end-point assessment is blinded. Study population: Adults, aged 18-70 years, diagnosed with a mTBI at the Emergency Department (ED) of the participating hospitals within 24 hours after injury are eligible for inclusion. Intervention: At two weeks post-injury the presence, severity, and type of post-traumatic complaints are assessed using the Rivermead Postconcussive complaints Questionnaire (RPQ). If a predefined minimum of complaints is present, a participant is randomised for one of the two interventions or the control group. The first intervention arm consists of symptom-targeted treatment with assignment to physical and/or occupational therapy. The second intervention arm involves psychoeducation about the complaints through telephonic counselling. The interventions are offered during three weeks from week 3-6 week post-injury. Main study parameters/endpoints: The primary outcome measure is the total RPQ sum score at three months postinjury. The secondary outcome measures are functional outcome and quality of life. Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Participants included in treatment arm 1 will undergo three to six therapy sessions with a physiotherapist and/or occupational therapist over a period of three weeks. This regimen may be potentially burdensome by its frequency but the risks associated with these treatments are low. Participants randomised to treatment arm 2 will receive three telephone calls over the course of three weeks, during which psychoeducation will be provided. This intervention is minimally burdensome and risk-free. All participants included in the interventional part of the study will complete questionnaires at three time points after injury and will receive two follow-up telephone calls three and six months post-injury for outcome assessment. This process is minimally burdensome and poses no risk. Finally, participants included in the registry will complete a limited set of questionnaires at three time points, which is also minimally burdensome and riskfree.

The purpose of this study is to understand the effects of mindfulness and fantasizing in reducing perseverative cognition underlying vulnerability for depression.

PulmoPrint is a clinical study at UMCG that investigates why some patients with unresectable stage III lung cancer stop responding to immunotherapy after chemoradiation. To do this, a small dose of a fluorescently labeled version of the immunotherapy drug durvalumab is given via an IV drip, after which a camera bronchoscopy is performed to visualize where and how much of the drug actually reaches the tumor and lymph nodes - before the actual durvalumab treatment starts.

We aim to determine feasibility, safety and efficacy of TDLN-targeted immune checkpoint inhibition in different doses (nivolumab) in patients with cervical cancer.

The goal of this clinical trial is to evaluate the feasibility of WGA-800CW with dedicated imaging systems for detection of invisible esophageal dysplasia in patients with Barrett's esophagus. The main questions it aims to answer are: * What is the optimal dose of WGA-800CW that maximizes the tumor-to-background ratio and enables clear visualization of the tumor? * Can fluorescence endoscopy with WGA-800CW in combination with qFME detect dysplastic esophageal lesions? In this non-randomized, non-blinded, prospective, feasibility intervention study, 49 participants with Barrett's esophagus will be included. Patients will undergo the combined procedure (qFME and/or OCT-NIRF and HD-WLE). WGA-800CW will be topically administered via a spray catheter during gastroscopy procedures and fluorescent signal will be assessed with qFME and/or OCT-NIRF.

Patients with newly diagnosed stage IV non-oncogene addicted NSCLC, who are fit for systemic treatment and don't have any symptoms of brain disease will undergo an MRI of the brain to screen for brain disease.

• Background There is a growing tendency to place a provisional crown immediately following implant placement. Clinical advantages are shortening of treatment duration and soft tissue guiding during healing resulting in better aesthetic outcomes. It was shown that good esthetic results can be achieved on the long term with immediate provisionalization of single-tooth implants placed in either fresh extraction sockets or after alveolar ridge preservation/reconstruction in the maxillary esthetic zone. One recent development in three-dimensional printing is digital press stereolithography (DPS), which overcomes the challenges of printing highly-filled viscous materials. This enables the use of more durable materials than traditional three-dimensionally printed provisional crowns and allows for rapid additive production of prosthetic restorations. Until date, no studies have been described investigating immediate loading of implants in the aesthetic zone using three-dimensional DPS-printers and their impact on patient-satisfaction. * Main research question The purpose of this one-year prospective case series study is to perform an assessment of patient-reported outcomes of single-tooth implants with immediate provisionalization using three-dimensionally printed provisional crowns. * Design (including population, confounders/outcomes) The study design is a prospective, single-arm observational study for evaluation of 30 patients with a failing tooth in the maxillary aesthetic region to be treated with an implant-supported provisional and definitive restoration by means of a provisional and definitive crown. Outcomes: registration of time/complications during the diagnostic/planning/manufacturing process, evaluation of clinical and radiographical performance and aesthetic outcome. * Expected results Satisfying results for patients and professionals (VAS-scores and PES/WES-scores)

Currently, in routine patient care PET/CT scan protocols used on high sensitivity large field of-view (LAFOV) PET/CT systems are based on protocols that historically were developed for standard field-of-view (SAFOV) PET/CT systems with a much lower sensitivity profile. In the current SAFOV-based imaging protocols, the maximum delay between injection and actual scanning is limited by increasing noise (due to radioactive decay) resulting in bad image quality. A major advantage of later time-point imaging in general is, that the target-to background ratio improves. With the high-sensitive LAFOV PET/CT scanner later time-point imaging becomes possible, and higher tumour-to background ratios can be obtained. Specifically for the 18F-Fluoroesradiol tracer, used to image estrogen receptor positive tumors, high physiological uptake in the liver and intestines hampers the visualization and quantification of liver metastases and peritoneal metastases. The aim of this study is to evaluate whether late time point imaging with the 18F-Fluoroestradiol tracer on the LAFOV PET/CT improves visualization and quantification of liver metastases and peritoneal metastases.

In this study, investigators will compare the effect of vicadrostat combined with empagliflozin with the effect of spironolactone combined with empagliflozin on renal function and changes in protein profiles in blood and urine. The hypothesis is that the renal and cardiac responses between vicadrostat and spironolactone differ due to mechanistic differences in their mode of action. Spironolactone is a mineralocorticoid receptor antagonist (MRA) and exerts its effect on a receptor, or a type of "receiver," found on various cells. Vicadrostat is an aldosterone synthase inhibitor (ASI) and inhibits aldosterone production. Therefore, both drugs affect aldosterone. However, studies evaluating the differences between MRAs (such as spironolactone) and ASI (such as vicadrostat) and examining their effects on the kidneys in patients with chronic kidney disease with concurrent cardiovascular disease, and/or heart failure are still lacking. For this study, all participants will be divided into two groups: * Group 1. Participants in this group will receive one tablet of vicadrostat (10 mg) and one tablet of empagliflozin (10 mg) daily for 26 weeks. * Group 2. Participants in this group will receive one tablet of spironolactone (25 mg) and one tablet of empagliflozin (10 mg) daily for the first four weeks. Participants in this group will then receive two tablets of spironolactone (50 mg) and one tablet of empagliflozin (10 mg) daily for the remaining 22 weeks. The spironolactone dosage may be adjusted during the study period (from 12.5 to 50 mg) based on blood test results.

Rationale: There is large heterogeneity in disease states of critically ill patients at ICU admittance and there is also large heterogeneity in their disease severity during ICU stay. Still, some patients may show remarkable similarities in disease patterns. There is a lack of understanding of causal mechanisms that lead to divergent outcomes in critically ill patients, and at the same time different diseases may share common underlying, yet unidentified, causal pathways that could explain similarities between different diseases. Objective: To explore the association between patient characteristics and the severity of organ failure in critically ill patients admitted to the ICU Study design: Prospective cohort study Study population: Adult critically ill patients in the ICU Intervention (if applicable): not applicable Main study parameters/endpoints: Maximum severity of organ failure observed during ICU stay measured by the maximum SOFA score and quality of life at one year follow-up

The goal of this clinical trial is to learn if conduction system pacing works as well as cardiac resynchronization therapy (CRT) post atrioventricular (AV) node ablation in adult patients with symptomatic heart failure and atrial fibrillation that is not suitable for rhythm control. The main question it aims to answer is: Is AV node ablation with conduction system pacing noninferior to AV node ablation with CRT for the hierarchical composite outcome of all-cause mortality, heart failure hospitalization or urgent heart failure visit, and meaningful improvement in heart failure-related quality of life? Participants will undergo: * An AV node ablation and be randomly assigned to receive either a conduction system pacing or a CRT. * Attend follow-up visits (in clinic or by telephone) at baseline, intervention day, 3-month, 12-month, 24-month, and 36-month after the procedure. * Complete questionnaires about heart failure symptoms and quality of life at baseline, 12 months, and yearly. * Have an echocardiogram, an electrocardiogram, and blood tests at baseline and 1 year * At selected centers: they will be asked to wear a bracelet that measures arterial stiffness for 30 minutes and provide a urine sample at baseline and 1 year.

The goal of this clinical trial is to learn if probiotics work to prevent or reduce metabolic side effects caused by antipsychotic medication in adults. The main question it aims to answer is: Do probiotics reduce weight gain, blood sugar levels, and blood fat levels in people using antipsychotics? Researchers will compare a probiotic (Ecologic® Barrier) to a placebo (a look-alike powder without active bacteria) to see if the probiotic is effective. Participants will: Take either probiotics or a placebo daily for 12 weeks (3 months) Dissolve two sachets in water and drink them each morning Visit the clinic (or receive home visits) four times: at the start, after 6 weeks, and after 12 weeks, plus an initial screening visit Undergo physical measurements (e.g., weight, blood pressure), complete questionnaires, and perform a cognitive test at specific visits Provide blood samples and stool samples at the beginning and end of the study Complete two 3-day food diaries during the study

Machine perfusion (MP) has become routine clinical practice in liver transplantation. However, as the field has matured, direct randomized comparisons between distinct MP modalities have become increasingly impractical, given that donor and graft characteristics often predetermine the optimal preservation strategy. Consequently, many studies continue to reference historical benchmark cohorts from the pre-perfusion era, or use risk scores developed before routine utilization of MP. These cohorts, while once valuable, fail to account for the paradigm shift that MP has introduced. Likewise, commonly used donor- and recipient-based risk scores were developed prior to the adoption of MP. While these scores aim to assess survival or morbidity after transplantation, none of them guide decisions about MP use or the most suitable perfusion protocol. As MP technologies continue to evolve there is a critical need for an updated reference framework that accurately reflects current clinical practice and captures the best achievable outcomes across all MP modalities.

Schema therapy helps people understand which emotional needs were not met during childhood, and how they can take care of those needs now. One important part of the therapy is the chairwork exercise, where people imagine talking to different parts of themselves (like the strict parent or the hurt child) using empty chairs. These exercises can be very helpful, but they can also be difficult for people who find it hard to imagine things in their mind. Virtual Reality (VR) can make these exercises easier and more powerful. VR creates a 3D world that feels real, using special equipment like a headset. In this world, people can see and interact with virtual characters that represent different parts of themselves. This can make the therapy more concrete and easier to understand, especially for people who struggle with imagination. In this study, the investigators want to compare the regular imagination-based exercise with the chairwork exercise done in Virtual Reality. Everyone who joins the study will do both versions of the exercise-one with imagination and one with VR. The order will be random. Before and after each exercise, a short assessment will be conducted to see how people feel. At the end, there will also be a short interview about their experience. The whole session will take about 1.5 to 2 hours. The investigators want to know if people experience the VR exercise differently than the regular imagination exercise. The investigators also want to know if these differences depend on how well someone can imagine things in their mind.

This randomized multicenter trial compares coronary artery bypass grafting (CABG) with percutaneous coronary intervention (PCI) in 358 patients with ischemic left ventricular dysfunction and multivessel coronary disease. The study evaluates differences in survival, major cardiovascular events, and quality of life over 4 years, and contributes to the international STICH 3.0 collaboration assessing long-term outcomes.

The cause of infertility can be due to a female factor or a male factor. In case of a male factor, it is often due to poor semen quality. However, the cause of poor quality is often unknown. In previous research, infertility problems in men were related to chemical processes in metabolism causing the formation of free radicals. Free radicals are physiological by-products of our body mechanisms. Free radicals are very reactive and can therefore react with a lot of molecules of cells within our body and cause damage. A balance between free radicals, which are also needed for physiological processes in the body, and antioxidants, which defuses the reactive free radicals, is most desirable. However, as stated in literature, there are a lot of factors that can influence extra free radical production, which causes overloading of the system, resulting in damage on cellular level. Free radicals in semen plasma and on the sperm cell could play a role in male infertility. Nonetheless, free radicals are not used as diagnostic markers due to the lack of detection systems, as free radicals are very short-lived. This study aims to introduce a new technique, called diamond magnetometry, to measure free radicals directly on the sperm cell and in serum. Diamond magnetometry involves very small diamond particles as magnetic sensors that engage a reaction with the free radicals on the sperm cell, causing signals that can be measured. To compare local free radical production with systemic free radical production, other diagnostic biomarkers are also measured in serum. It is hypothesized that the composition of seminal microbiome could influence the free radical concentration. Therefore, this study also aims to explore the microbiota composition and see if this has an influence in semen quality and free radical production. At last, this study also want to correlate standard semen parameters (defined by the World Health Organisation), lifestyle factors and food intake, to detect a role for lifestyle in the production of free radicals.

The goal of this clinical trial is to evaluate whether psilocybin therapy can effectively treat depression and psychological distress in adult patients with COPD, ALS, MS, or APD who have at least 6 months life expectancy. The main questions it aims to answer are: * Can psilocybin therapy safely reduce depressive symptoms compared to low-dose control? * Will the therapeutic effects be rapid and sustained over a 6-month period? Researchers will compare patients receiving two escalating doses of psilocybin (15mg followed by 25mg) against those receiving two low doses (1mg) to see if the higher doses lead to greater improvements in depression, anxiety, demoralization, and quality of life. Participants will: * Attend three preparation sessions with psychotherapists (1-2 hours each) * Undergo two supervised psilocybin dosing sessions (6-8 hours each) * Complete five integration therapy sessions following the dosing sessions * Participate in follow-up assessments at 6 weeks, 3 months, and 6 months * Have access to a digital care platform and peer support groups during the 6-month follow-up period * Optional: Control group participants may receive one high-dose psilocybin session (25mg) after the initial study period

Rationale: Sodium glucose co-transporter 2 (SGLT2) inhibitors are a relatively new class of drugs originally developed for the treatment of diabetes. Cardiovascular outcome trials with these drugs showed also beneficial effects of these agents on heart failure, cardiovascular disease and kidney outcomes. Secondary analyses from these trials demonstrated that these benefits were consistent in patients with or without type 2 diabetes and with or without chronic kidney disease (CKD) with a lower eGFR threshold of 20 mL/min/1.73m2. However, it is not yet clear if these drugs can also be used in patients with severe kidney disease who require dialysis. This is in part explained because SGLT2 inhibitors bind to a transporter which is located in the luminal side of proximal tubes in the kidney. If kidney function is low, and these patients have no or limited filtering capacity, it is possible that the efficacy of these drugs decrease. Notwithstanding, several animal experiments and preliminary clinical data have suggested that these drugs do have kidney and cardiac protective effects in case of severely decreased kidney function. The investigators hypothesize that SGLT2 inhibitors are distributed to several tissues in the body on top of the kidney and therefore the investigators would like to investigate the specific tissue distribution of SGLT2 inhibitors in patients on dialysis with-and without residual diuresis.

When using highly conformal radiotherapy techniques, such as proton therapy, a controlled breathing pattern and a minimal breathing amplitude could greatly benefit the treatment of mobile tumors. This reduction in tumor motion may be achieved with the use of a ventilator that is able to regulate and modulate the breathing pattern. CPAP provides a constant level of positive airway pressure. Compared to spontaneous breathing, the use of CPAP increased lung volume and can result in a significant decrease in tumor movement and a significant decrease in both mean lung and mean heart radiation dose. These results were found in patients treated for limited stage disease, it is not clear if this approach is feasible for patients with more advanced stage of disease that undergo radiotherapy with curative intent. With Bilevel Positive Airway Pressure (BiPAP), tidal volume excursions are determined by the pressure difference between the set inspiratory positive airway pressure (IPAP) and the set expiratory positive airway pressure (EPAP). This mode of ventilation increases lung volume comparable to CPAP, but also to control tidal volumes and breathing frequency. However, BiPAP has never been studied in the setting of motion mitigation during radiotherapy and BiPAP might be more difficult to adjust to for patients compared to CPAP. Therefore, the current study is proposed to evaluate whether or not CPAP or BiPAP is of benefit in patients that undergo radiotherapy for larger intra-thoracic tumor volumes.

Motive: In order to improve the treatment technique, a comprehensive follow-up program is needed to obtain all relevant patient, treatment and toxicity data from lung cancer patients. Goal: To set-up and maintain a database containing treatment results in terms of tumor control, side effects, complications and patient-reported quality of life. A standard database of patients receiving photon treatment will be created. These data are then linked to dose-volume data of radiotherapy, with the aim to build prediction models for both tumor control and toxicity after radio (chemo) therapy that can later be used for selecting patients for proton treatment.

Rationale: Bronchoscopic lung volume reduction using endobronchial valves (EBV) has emerged as a viable treatment option for eligible patients with severe emphysema. In all studies conducted so far, exercise capacity has only been measured using the 6-minute walk distance test (6MWT). It is known that patients with COPD frequently experience problems during ADL, which can lead to avoidance of or care dependency for performing certain tasks and have a significant social impact on their lives. Patients report that it is easier to perform ADLs after EBV treatment. Previously it was found that it was easier for patient to perform these activities after the EBV treatment. However, the physiological load during these ADLs has never been investigated before. Potentially, EBV treatment could improve the metabolic load and consequently symptom perception, thus enhancing the execution of ADLs, which is an important patient-centred outcome. However, this has not been investigated so far. Objective: To investigate the change in exercise physiology during daily activities after EBV treatment. Study design: Observational study in which the study population will be asked to perform some additional test during regular visits for the bronchoscopic lung volume reduction treatment with valves. Study population: Patients with emphysema who are scheduled for a bronchoscopic lung volume reduction treatment using endobronchial valves. Intervention: Not applicable Main study parameters: The change in task-related oxygen uptake measured with a mobile oxygen device during activities of daily life 6 months after EBV treatment.