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Endoscopic Ultrasound: “A Window to the Inside of Your Body”


In its quest to always providing its patients with the latest and most advanced diagnostic and therapeutic tools, Riverside Medical Clinic (RMC) has recruited gastroenterologist Dr. Eric Choi to develop an endoscopic ultrasound (EUS) program for the greater Riverside community. Having recently joined RMC, Dr. Choi talks about how working with Riverside Community Hospital on this new project will affect patients and the future of an exciting area of cancer diagnosis and treatment.

What is endoscopic ultrasound (EUS)?

Endoscopic ultrasound is a window to the inside of the body. A regular endoscope utilizes fiber optic technology in a thin, flexible tube, equipped with a camera and light source. Once the endoscope is inserted into the body, it allows the physician to look inside the body, along the surface lining of the GI tract, such as in the esophagus, stomach, and colon. EUS is an immensely powerful tool in that it adds an ultrasound catheter to the tip of the endoscope. Ultrasound allows the physician to not only observe the lining of the GI tract, but also to see across the walls of the GI tract to adjacent organs in the body.

Ultrasound is a technology that has been around for a long time. Obstetricians can visualize a growing fetus by placing an ultrasound probe on the abdomen of a pregnant woman, allowing a non-invasive method of studying the developing fetus. Using a similar concept with EUS, we can now visualize numerous structures in the body in high detail in much less invasive ways than were previously available. Since endoscopy allows the ultrasound probe to be placed very close to the organ being examined, the images obtained by EUS are often more useful than images provided by other methods.

What are the primary uses of EUS?

There are literally dozens of applications for EUS, a technology which has steadily been improved and perfected over the past thirty years. Patients will typically be referred to a specialist in endoscopic ultrasound by another gastroenterologist or primary care physician, who has found something suspicious on a radiologic examination, such as a CT scan or MRI. Often these other studies do not provide the clarity or detail necessary to answer a clinical question, and as a result, EUS is requested for a closer and more detailed look. One of the most critical uses of EUS is to diagnose and stage cancers. Often times the prognosis of a patient diagnosed with cancer is closely tied to the stage of the cancer—in other words, how advanced the cancer is. EUS has been demonstrated in a number of studies to be the best test to determine how advanced certain cancers are.

EUS is useful in not only diagnosis but also in providing therapy. For example, EUS can place a very fine needle into a cyst and withdraw fluid, thereby reducing the size of the cyst but also allowing the physician to characterize whether a cyst is a precancerous or even cancerous type cyst. EUS allows the placement of small gold markers, called fiducials, into certain cancers to allow better targeting and to reduce the amount of radiation used during radiation therapy. Since certain masses are difficult to distinguish from the surrounding tissue, implanting these gold markers helps the radiation oncologist to adjust the aim of the radiation, based on the real-time location of the gold markers in the targeted area.

How will using EUS technology benefit patients of RMC and the greater Riverside area?
Endoscopic ultrasound is a really exciting technology with a vast number of applications. Although doctors are getting better at diagnosing and treating cancers, we are always looking for the least invasive, most accurate and safe method to treat our patients. EUS represents a large, bold step in that direction.

I am very excited to be developing this EUS program for the Riverside community. It is a technology that is not yet widely available. In fact, patients are currently referred to hospitals outside the county to undergo EUS. Having this technology locally will allow a greater convenience to patients in obtaining the best care, but additionally allow patients to be treated in a more efficient and timely manner. It truly is an honor to be able to bring this technology to Riverside, and I look forward to providing the best care for the patients of the Inland Empire.

Dr. Eric Choi is a gastroenterologist at the Riverside Medical Clinic. A graduate of Dartmouth College, he completed his medical school training and residency in Philadelphia and is double fellowship-trained in gastroenterology with a focus in therapeutic endoscopy and endoscopic ultrasound. His practice is located at 6405 Day Street in Riverside, and he can be contacted at (951) 697-5464.

Riverside Medical Clinic is the largest private provider of ambulatory care in the Inland Empire. If you’d like to find a primary care physician or a specialist, call the clinic’s physician referral line at (951) 683-6370 or go to http://www.riversidemedicalclinic.com for an online physician directory by location and specialty.