Coronary CT Angiography Screening in At-risk Cancer Survivors

Coronary computed tomography angiography (CCTA) may be an effective screening method to detect coronary artery disease (CAD) in adult survivors of Hodgkin’s lymphoma. A study published recently in Cancer showed that the imaging modality detected CAD in about 40 percent of survivors; whereas, more traditional screening modalities like echocardiography or treadmill stress testing did not show significant corresponding changes in plaque. 

“CCTA may offer an effective noninvasive tool for the management of at-risk cancer survivors, permitting the identification of those who might benefit from lifestyle and/or medication interventions and those for whom lower levels of monitoring may be appropriate,” wrote study author Daniel A. Mulrooney, MD, MS, of St. Jude Children’s Research Hospital, and colleagues.

Although in the past CCTA exposed patients to about 12 millisieverts of radiation, advances in technology have decreased the average exposure to less than one millisievert in some cases.

In this study, Mulrooney and colleagues examined 31 Hodgkin’s lymphoma survivors; 42 percent of whom had been treated with radiotherapy only and 58 percent were treated with multimodality therapy. The median age of patients was 40 and patients were a median of 24 years old from their initial diagnosis. Patients underwent CCTA, echocardiography, electrocardiography and treadmill stress testing to monitor for CAD, which was defined at 50 percent of greater occlusion of the left main or 70 percent or greater occlusion of the left anterior descending, left circumflex or right coronary arteries.

Overall, the researchers identified 39 coronary artery lesions, 59 percent of which were calcified and 10 percent of which were obstructive. CCTA identified CAD in 39 percent of the survivors. Three of the participants who had been treated with radiotherapy alone had four obstructive lesions; nine patients had nonobstructive lesions. Nineteen patients had their radiation dose archived. The CCTA as measured by dose-length product was 661 milligray-cm.

CCTA identified CAD in 12 patients. However, few positive findings were identified using the other more traditional modalities. Of the 12 patients found to have CAD on CCTA, seven had a positive electrocardiogram, one had a positive echocardiogram and one had a positive stress test. No patient with nonobstructive lesions had a positive stress test or echocardiogram.

“The findings of the current study should be interpreted within the context of evolving therapies for Hodgkin’s lymphoma,” the researchers wrote. “The most severe disease (obstructive lesions) was identified among those individuals with the highest radiation exposures. Doses have been reduced, if not eliminated, in newer protocols, which will hopefully lead to a reduced risk of CAD among survivors of Hodgkin’s lymphoma.”