Algorithm lets cancer patients skip CT scans for pulmonary embolism
A clinically focused algorithm could allow cancer patients with suspected pulmonary embolism to forego CT imaging, new research suggests.
Computed tomography pulmonary angiography (CTPA) is currently the gold standard for diagnosing PE. However, its use entails radiation exposure and often can lead to longer hospital stays, both of which can be problematic for cancer patients. As such, there has been increased interest in finding alternative methods to diagnose pulmonary embolism in this patient population.
The YEARS algorithm can help address this issue; it assesses PE probability based on three clinical items and applies a probability-dependent, D-dimer threshold, with measures under the threshold used to rule out PE. It has been shown to be both safe and effective in multiple patient subgroup.
“Its use in patients with cancer is debated because post hoc analyses have shown that the incidence of new [venous thromboembolism] after excluding acute PE based on the YEARS algorithm was higher in patients with cancer than in patients without cancer,” Menno V. Huisman, MD, PhD, with the Leiden University Medical Center in the Netherlands, and co-authors explained. “Consequently, current guidelines refrain from recommending the use of YEARS or similar clinical decision rules in patients with cancer, and usual practice is often to perform CTPA directly without D-dimer testing.”
The Hydra study sought to assess the efficacy of the YEARS algorithm on a group of patients with active cancer. It included a group of 692 patients divided into two groups—one who underwent CTPA only and another whose treatment was determined based on the YEARS protocol. Outcomes were measured based on instances of centrally adjudicated symptomatic venous thromboembolism or possible PE-related death within 90 days after ruling out PE at baseline. Negative CTPA baseline exams also were included in a secondary analysis.
Around 15% of the patients were diagnosed with PE at baseline; there were fewer instances of adverse outcomes in the YEARS group, with just 1.8% having of the patients in whom PE was excluded having negative outcomes compared to 5.5% in the CTPA-only group. In the intention-to-diagnosis analysis, the absolute risk difference between the YEARS algorithm and CTPA was only −2.6%.
The team suggested that their findings indicate that the YEARS algorithm is likely as safe as CTPA-only strategies in this group of patients.
“Importantly, PE could be excluded without CTPA in a relevant proportion of 22% of patients managed according to the YEARS algorithm, saving costs and decreasing exposure to ionizing radiation,” the authors noted, adding that “the latter of which is of relative importance in this population, and is saving patients from receiving potentially harmful contrast material.”
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In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.