Clinical Research Directory

Evaluation of the Efficacy of Diagnostic Support Algorithms in Chest X-rays- LuAna Trial

This study aims to evaluate whether the use of AI as a physician support tool is associated with an increase in the detection rate of chest radiographic findings in adults with respiratory complaints, compared to diagnosis performed exclusively by doctors, without AI support. This is a cluster-randomized clinical trial, following the stepped wedge design, and adhering to the guidelines of the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT). In this study, the Diagnostic Support Solution for Chest X-rays - LungAnalysis (LuAna), developed by the Hospital Israelita Albert Einstein (HIAE) within the PROADI-SUS Banco de Imagens, was used. The clinical trial will be conducted in multiple centers with a diverse population from the public health system, to ensure that the algorithms are validated across a broad demographic profile. The expected benefits are significant, providing greater security for patients, increasing doctors' confidence in interpreting chest X-rays, promoting efficiency and cost savings for healthcare services, and offering promising prospects for other AI applications in imaging diagnostics.

Human Learning of New Structured Information Across Time and Sleep

Acting adaptively requires quickly picking up on structure in the environment and storing the acquired knowledge for effective future use. Dominant theories of the hippocampus have focused on its ability to encode individual snapshots of experience, but the investigators and others have found evidence that it is also crucial for finding structure across experiences. The mechanisms of this essential form of learning have not been established. The investigators have developed a neural network model of the hippocampus instantiating the theory that one of its subfields can quickly encode structure using distributed representations, a powerful form of representation in which populations of neurons become responsive to multiple related features of the environment. The first aim of this project is to test predictions of this model using high resolution functional magnetic resonance imaging (fMRI) in paradigms requiring integration of information across experiences. The results will clarify fundamental mechanisms of how humans learn novel structure, adjudicating between existing models of this process, and informing further model development. There are also competing theories as to the eventual fate of new hippocampal representations. One view posits that during sleep, the hippocampus replays recent information to build longer-term distributed representations in neocortex. Another view claims that memories are directly and independently formed and consolidated within the hippocampus and neocortex. The second aim of this project is to test between these theories. The investigators will assess changes in hippocampal and cortical representations over time by re-scanning participants and tracking changes in memory at a one-week delay. Any observed changes in the brain and behavior across time, however, may be due to generic effects of time or to active processing during sleep. The third aim is thus to assess the specific causal contributions of sleep to the consolidation of structured information. The investigators will use real-time sleep electroencephalography to play sound cues to bias memory reactivation. The investigators expect that this work will clarify the anatomical substrates and, critically, the nature of the representations that support encoding and consolidation of novel structure in the environment.

Chemoradiation and Consolidation Chemotherapy With or Without Oxaliplatin for Distal Rectal Cancer and Watch and Wait

Background: Neoadjuvant chemoradiation (nCRT) has been considered the preferred initial treatment strategy for distal rectal cancer. Advantages of this approach include improved local control after radical surgery but also the opportunity for organ preserving strategies (Watch and Wait - WW). Consolidation chemotherapy (cCT) regimens using fluoropyrimidine-based with or without oxaliplatin following nCRT have demonstrated to increase complete response and organ preservation rates among these patients. However, the benefit of adding oxaliplatin to cCt compared to fluoropyrimidine alone regimens in terms of primary tumor response remains unclear. Since oxaliplatin-treatment may be associated with considerable toxicity, it becomes imperative to understand the benefit of its incorporation into standard cCT regimens in terms of primary tumor response. The aim of the present trial is to compare the outcomes of 2 different cCT regimens following nCRT (fluoropyrimidine-alone versus fluoropyrimidine+oxaliplatin) for patients with distal rectal cancer. Methods: In this multi-centre study, patients with magnetic resonance-defined distal rectal tumors will be randomized on a 1:1 ratio to receive long-course chemoradiation (54Gy) followed by cCT with fluoropyrimidine alone versus fluoropyrimidine+oxaliplatin. Magnetic resonance (MR) will be analyzed centrally prior to patient inclusion and randomization. mrT2-3N0-1 tumor located no more than 1cm above the anorectal ring determined by sagittal views on MR will be eligible for the study. Tumor response will be assessed after 12 weeks from radiotherapy (RT) completion. Patients with clinical complete response (clinical, endoscopic and radiological) will be enrolled in an organ-preservation program (WW). The primary endpoint of this trial is decision to organ-preservation surveillance (WW) at 18 weeks from RT completion. Discussion: Long-course nCRT with cCT is associated with improved complete response rates and may be a very attractive alternative to increase the chances for organ-preservation strategies. Fluoropyrimidine-based cCT with or without oxaliplatin has never been investigated in the setting of a randomized trial to compare clinical response rates and the possibility of organ-preservation. The outcomes of this study may significantly impact clinical practice of patients with distal rectal cancer interested in organ-preservation.

Standardizing Right Hemicolectomy for Colon Cancer

A surgical intervention might be highly variable amongst surgeons and centers. This variability has a potential relevance concerning clinical outcomes. For right-sided colon cancer, the laparoscopic right hemicolectomy (LRHC) knows substantial variation. Especially since the surgical technique has been evolving during the latest decade with the introduction of intracorporeal anastomosis, a dissection technique within the correct embryological planes (complete mesocolic excision) and central vascular ligation of the segmental branches at its origin, resulting in an optimal lymph node dissection. Given the insights from recent studies showing the association between quality of surgery and relevant clinical outcomes, there is a great need for a formative quality assessment of LRHC. Detailed objective assessment of the LRHC is currently not performed in clinical practice nor in surgical training. Quality assessment of LRHC has great potential to improve surgical training and furthermore, implementation of a standardized technique will ultimately lead to better quality of care for patients suffering from right-sided colon cancer. The main objective of this study is to improve surgical outcomes for patient with right-sided colon cancer by a prospective sequential interventional cohort study that aims to standardize the surgical technique with subsequent controlled implementation after standardized review of the current practice in a nationwide multicenter setting. The primary endpoint is the 30-day morbidity according to the Clavien-Dindo classification system.