Use of Computed Tomography Pulmonary Angiography for Suspected Pulmonary Embolism in Patients with Malignancy- a Single Center Experience

Background: Pulmonary embolism (PE) is a potentially lethal condition commonly suspected in patients with malignancy. Computed Tomography Pulmonary Angiography (CTPA) is increasingly used in the diagnosis of PE, and guidelines have incorporated various screening tools including the Modified Geneva and Wells criteria to facilitate exclusion of pulmonary embolism. There is an increased risk of venous thromboembolism in patients with active malignancy and therefore an increased suspicion in patients who present to the emergency department (ED) with concerning symptoms.

Methods: This is a retrospective analysis at a single tertiary care institution. All patients initially diagnosed with an active malignancy since 2005 and underwent a CTPA between January 2010 and October 2015 were reviewed. Patients were excluded if the CTPA was performed in the setting of trauma, a history of benign malignancy, or if the diagnosis of malignancy was made subsequent to the CTPA. Data collected included patient demographics, clinical presentation, type of malignancy and treatment regimen received. The modified Geneva and Wells criteria were applied to all patients independent from the initial ED risk assessment for a PE.

Results: There were 796 patient records reviewed, of which 162 patients met inclusion criteria. Out of these 162 patients, only 8 (4.9%) were found to have a pulmonary embolism. All patients with a positive CTPA had an intermediate risk per the Geneva criteria while only 62.5% had an intermediate risk per the Wells criteria. Of the 154 patients with a negative CTPA, 71.5% and 78.7% had an intermediate risk; 22.5% and 18.7% were classified as low risk based on Wells and Geneva criteria, respectively. The median age of patients was 59 years old, and the majority were male (58%). The most common malignancies in which a CTPA was ordered were lung cancer (27.7%) followed by breast cancer (14.9%) and prostate cancer (6.8%). Despite a negative CTPA, 82 out of 154 patients (53%) were admitted to the hospital.

Conclusion: Pulmonary embolism is commonly associated with and frequently suspected in patients with active malignancy. The incidence of PE over a 5-year period in oncology patients was 5% in our emergency department. In total, 18.7% to 22.5% of patients could have avoided a CTPA if scoring was based on the Wells or Geneva criteria. Based on the review at our institution, the modified Geneva and Wells criteria are not adequate, and a new tool needs to be developed for risk stratification for the diagnosis of PE specifically in patients with active malignancy.