The latest medical research on Radiation Oncology

This study aims to highlight presentations, acute findings and imaging phenotypes of patients presenting to the emergency department (ED) within 30 days of a transcatheter aortic valve replacement (TAVR).

A retrospective review of patients diagnosed with aortic valve disease who underwent a TAVR between Jan 2015 and Nov 2021 at a large academic medical center was completed. From an initial 1271 patients, 146 were included based on their presentation to the ED within 30 days post-TAVR procedure. Patient data, including ED presentation details and imaging results, were recorded and de-identified.

Of the 146 post-TAVR patients, there were 168 ED visits within 30 days. The median time to ED after TAVR was 12 days. Respiratory symptoms were the most common complaint (27%). Neurological (23%) and cardiovascular symptoms (18%) followed. Cross-sectional imaging was conducted 250 times across visits, with an average of 1.7 scans per patient. CTs were most frequently used, followed by ultrasounds, especially echocardiograms and duplex extremity vasculature ultrasounds. 30.1% of patients had acute findings from imaging. Specific findings included heart failure (5.5%), access site complications (5.5%), pneumonia (5.5%), intracranial pathologies (3.4% for strokes and 0.7% for hematoma), and pleural effusion (3.4%). Echocardiograms and CTA chest were most associated with significant acute findings.

Our study highlights the vital role of early and accurate imaging in post-TAVR patients within 30 days post-procedure. As transcatheter approaches rise in popularity, emergency radiologists become instrumental in diagnosing common post-procedural presentations. Continued research is essential to devise post-discharge strategies to curtail readmissions and related costs. Proper imaging ensures prompt, effective care, enhancing overall patient outcomes.

Sickle cell disease (SCD) is a genetic hematological disorder associated with severe complications, such as vaso-occlusive crises, acute chest syndrome (ACS), and an increased risk of thromboembolic events, including pulmonary embolism (PE). The diagnosis of PE in SCD patients presents challenges due to the overlapping symptoms with other pulmonary conditions. Our previous study revealed that nearly 96% of computed tomography pulmonary angiography (CTPA) scans in SCD patients were negative for PE, highlighting a gap in understanding the significance of CTPA findings when PE is absent.

In this retrospective follow-up study conducted at the Salmaniya Medical Complex in Bahrain, we examined SCD patients with HbSS genotypes who underwent CTPA from January 1, 2018, to December 31, 2021, for suspected PE, but the results were negative. The aim of this study was to identify alternative diagnoses and incidental findings from CTPA scans. Experienced radiologists reviewed the CTPA images and reports to assess potential alternative diagnoses and incidental findings, incorporating an additional analysis of chest X-rays to evaluate the diagnostic value of CTPA. Incidental findings were classified based on their location and clinical significance.

Among the 230 evaluated SCD patients (average age 39.7 years; 53% male) who were CTPA negative for PE, 142 (61.7%) had identifiable alternative diagnoses, primarily pneumonia (49.1%). Notably, 88.0% of these alternative diagnoses had been previously suggested by chest radiographs. Furthermore, incidental findings were noted in 164 (71.3%) patients, with 11.0% deemed clinically significant, necessitating immediate action, and 87.8% considered potentially significant, requiring further assessment. Notable incidental findings included thoracic abnormalities such as cardiomegaly (12.2%) and an enlarged pulmonary artery (11.3%), as well as upper abdominal pathologies such as hepatomegaly (19.6%), splenomegaly (20.9%), and gallstones (10.4%).

This study underscores the limited additional diagnostic yield of CTPA for identifying alternative diagnoses to PE in SCD patients, with the majority of diagnoses, such as pneumonia, already suggested by chest radiographs. The frequent incidental findings, most of which necessitate further evaluation, highlight the need for a cautious and tailored approach to using CTPA in the SCD population.

Recent advancements in medical imaging have transformed diagnostic assessments, offering exciting possibilities for extracting biomarker-based information. This study aims to investigate the capabilities of a machine learning classifier that incorporates dual-energy computed tomography (DECT) radiomics. The primary focus is on discerning and predicting outcomes related to pulmonary embolism (PE).

The study included 131 participants who underwent pulmonary artery DECT angiography between January 2015 and March 2022. Among them, 104 patients received the final diagnosis of PE and 27 patients served as a control group. A total of 107 radiomic features were extracted for every case based on DECT imaging. The dataset was divided into training and test sets for model development and validation. Stepwise feature reduction identified the most relevant features, which were used to train a gradient-boosted tree model. Receiver operating characteristics analysis and Cox regression tests assessed the association of texture features with overall survival.

The trained machine learning classifier achieved a classification accuracy of 0.94 for identifying patients with acute PE with an area under the receiver operating characteristic curve of 0.91. Radiomics features could be valuable for predicting outcomes in patients with PE, demonstrating strong prognostic capabilities in survival prediction (c-index, 0.991 [0.979-1.00], p = 0.0001) with a median follow-up of 130 days (IQR, 38-720). Notably, the inclusion of clinical or DECT parameters did not enhance predictive performance.

In conclusion, our study underscores the promising potential of leveraging radiomics on DECT imaging for the identification of patients with acute PE and predicting their outcomes. This approach has the potential to improve clinical decision-making and patient management, offering efficiencies in time and resources by utilizing existing DECT imaging without the need for an additional scoring system.