Algorithm allows cancer patients to avoid CT scans for pulmonary embolism

July 14, 2026 - 09:20

A new clinical algorithm may help cancer patients avoid unnecessary CT scans when doctors suspect a pulmonary embolism, a potentially fatal blockage in the lungs. Researchers have developed a decision-making tool that uses simpler, non-radiation-based tests to rule out the condition in certain low-risk cases.

Pulmonary embolism is a common complication for cancer patients, who face a higher risk of blood clots due to both the disease and its treatments. Traditionally, a CT pulmonary angiogram is the gold standard for diagnosis, but it exposes patients to contrast dye and ionizing radiation. For those already undergoing repeated scans for cancer monitoring, this added exposure raises concerns.

The new approach relies on a combination of a blood test called the D-dimer, adjusted for age, and a clinical assessment of symptoms. In a recent study, the algorithm accurately identified which cancer patients could safely skip the CT scan without missing a dangerous clot. The method cut the number of scans by roughly a third in the tested group, while maintaining a high safety margin.

Doctors caution that the algorithm is not for everyone. It works best for patients with stable cancer who are not on active chemotherapy or have no recent surgery. For those with severe symptoms or high clinical suspicion, a CT scan remains necessary. Still, the findings offer a practical way to reduce radiation exposure and healthcare costs, while sparing patients from unnecessary procedures. The research team now plans to test the algorithm in broader hospital settings to confirm its reliability.