“I devoted this space in February to a discussion on advancing technology in the echo lab. In that column I spoke of the need for a champion, education and training, implementation plans, and evaluation. I thought it would be encouraging to hear about such a process from a lab which had successfully implemented advanced echo technologies into their daily process. I hope their experience encourages others to look past the barriers and persistently press on to advance technology in the echo lab.” —Elizabeth McIlwain, Council Chair
When most people think of cancer, they might not immediately think of echocardiography, but during certain treatment regimens it is easy to recognize the intricate role that cardiac imaging plays. There is no denying the important link between cancer therapy and cardiac function monitoring, especially when it comes to the use of the most widely used chemotherapy agent. At the University of Texas MD Anderson Cancer Center in Houston, we are proud to say the echocardiography laboratory functions somewhat differently than at most institutions and would like to emphasize how our lab has embraced new technology in ultrasound imaging.
Echocardiography plays a vital role in our institution. People come from all over the world to enroll in our specialized clinical trials. There are over 100 clinical trials which utilize echocardiography as the main imaging modality for research in our institution. In 2012, we were designated an Academic Imaging Core Lab by the ASE. Echoes performed for research purposes are very common in our lab. To be included in a clinical trial, a patient must have a left ventricular (LV) ejection fraction (LVEF) > 50% which is our institutionally defined normal from our echo lab–based variability analysis. Patients with cancer also suffer from a variety of illnesses including the usual spectrum of cardiovascular disorders. We perform approximately 16,000 studies annually. Many patients are routinely referred to the echo lab for assessment and monitoring of LV function prior to and during chemotherapy or immunotherapy and for cardiac evaluation following combined treatment or status post high risk medications.
Our mission is to be the best and most technologically advanced cardiac imaging laboratory in a cancer center and to offer the most accurate assessment of cardiac function to our patients undergoing cancer therapy. Part of achieving this mission is the utilization of advanced cardiac applications such as three-dimensional (3D) imaging and speckle-tracking echocardiography (STE) for strain analysis in the lab on a daily basis. Many types of cancer, such as breast, melanoma, sarcoma, and thyroid, can metastasize to the heart. 3D echocardiography is used to identify the extent, size, and location of cardiac masses, tumors, and thrombus. In pediatrics, even the smallest of our patients have STE studies with strain analysis while they are undergoing treatment.
When we began this process in 2007, none of our sonographers knew about strain and only one knew how to perform 3D imaging. If only one person in the lab is trained to perform any of the advanced imaging modalities, your lab will eventually encounter issues. We decided it was better to intensively train everyone in the lab, including the physicians, on the advanced cardiac applications (3D and STE). We began with 3D imaging. We worked with each and every sonographer as often as possible until he or she demonstrated competency in this modality.
The following year we introduced STE for strain analysis into the lab. The introduction of this new application created anxiety among some sonographers in the lab because the principles of strain imaging were initially daunting. With just one ultrasound system capable of strain analysis (we now have 6), we rotated each sonographer on a daily basis for the purpose of training. This training included proper acquisition protocols (frame rates, sector width, and heart rates), data interpretation, and correlation of strain curves with overall LV function. Introducing this technology resulted in an improvement in the quality of echoes performed. Suddenly, it was extra important to visualize the left ventricle in order to perform strain analysis.
Dr. Jose Banchs has been the medical director since April 2010. He expanded the program extensively. We have worked together systematically to obtain the highest quality of ultrasound imaging possible. We introduced the concept of strain analysis and 3D imaging to the various medical oncology teams at MD Anderson. Dr. Banchs gave presentations to these providers demonstrating how the echo lab uses these measures to accurately assess global and regional cardiac function. The information also included our lab’s established values for normal LV longitudinal strain and how we include this information in the echocardiogram report. We added custom statements regarding strain values to our PACS for ease of physician interpretation. On the echo report, we consistently report two-dimensinoal LVEF (bi-plane method of disks), 3D LVEF, strain values, and whether they are normal or abnormal. Contrast is also heavily utilized for accurate assessment of ejection fraction. The value and quality of echocardiography is demonstrated by the inclusion of such relevant information in the final report.
Our protocol includes strain analysis and 3D imaging for every patient. Analyzing the strain information is done real-time, while the patient is in the room, or immediately after completing the study if the sonographer is confident of the quality of images. We use the bi-plane method of disks to precisely quantify LVEF in addition to 3D LVEF measurements. The LVEF is an important number for the medical oncologist because it helps determine the course of treatment for the patient.
Does the patient qualify for enrollment in a clinical trial based on the echocardiogram results? Has there been a drop in ejection fraction >10% since starting therapy? Has the heart recovered enough to recommence treatment? These are questions answered daily by our cardiology team. Physicians throughout MD Anderson await results prior to staring chemotherapy. Hence every echo is interpreted and finalized on the same day it is performed.
Introducing advanced imaging techniques to the lab was challenging and definitely a stepwise process. We built on a strong foundation of knowledge and directed hands-on practice. It is gratifying to know the work done in our echocardiography lab helps the physicians provide the cardio-protective therapy our patients deserve as a result of our efforts.