Whether you are a patient, a practitioner, or a concerned relative or friend, you may have specific concerns or unanswered questions about EUS, its uses, or the patient's wellbeing and comfort. Here, we like to give you an opportunity to ask your own questions, and to read the answers to questions frequently asked.
Please take a moment to read the questions we've posted below. If you'd like to see the accompanying answer, just click on the appropriate question.
If you'd like to ask a question of your own, you will have an opportunity to do so at the bottom of this page.
What is EUS?Question:
What is EUS?
Answer:
Endoscopic Ultrasonography, or EUS, joins the medical technique of
endoscopy with the high frequency sound-wave technology you may know as
ultrasound. This state-of-the-art combination allows the doctor to
"microscopically" examine tissue not only within the digestive tract, but
also surrounding it. Like endoscopy, EUS uses a flexible tube called an
endoscope, which works like a periscope. The doctor inserts this tube into
the digestive tract through the mouth or the rectum to examine internal
organs and photograph and videotape the findings. EUS is as comfortable as
regular endoscopy, although it takes longer because it is more precise, and
because there are more details for the doctor to examine and interpret.
Question:
How is EUS different than regular endoscopy?
Answer:
Finding an abnormality with regular endoscopy is like seeing the tip of an iceberg. Endoscopy shows only the inner surface of the digestive tract and cannot show the abnormality beyond the visible surface. But in the same way a ship's sonar can depict the whole iceberg under water, the high-frequency of EUS reveals the full extent and nature of abnormalities, including information that is critical to accurate diagnosis and optimum care. In skilled hands, EUS can even locate abnormalities not detectable by any other means.
Question:
How does EUS differ from Magnatic Resonance Imaging (MRI), Computed Tomography Scan (CT) or a regular sonogram?
Answer:
EUS is done from inside the body, near or even touching the targeted area, so that a finer, higher frequency imaging energy can be used. Sonograms, and MRI and CT scans must image internal organs from outside the body, losing resolution in the process. The superior resolution of EUS shows all five layers of the digestive tract wall, almost like a microscope. No other test can do as well. Because it is video-based, EUS also provides a seamless stream of data, eliminating the unseen and unrecorded gaps between the still images of scans.
Comparing these other tests to EUS is like comparing an enlargement of one person's eye from a class photo to a high-resolution video close-up of just an eye. Regardless of how big the enlargement is, the graininess makes it impossible to count the eyelashes. In a video close-up, you can not only count the lashes, but you can determine their length, follow the eye as the head turns, see how often the eye blinks, and so on. EUS is more like a video close-up than like a still photo enlargement.
Question:
What about thin-slice CT and other new advances like MRI?
Answer:
The theory behind thin-slice CT is that by taking more pictures closer together, a small tumor or abnormality is less likely to be missed in the gaps between shots. But such techniques do not overcome the resolution problem: more pictures don't help if the resolution is too grainy to detect a small abnormality in the first place. Also, most of the digestive organs move so they are always at least somewhat out of focus with CT scan or MRI. EUS is like a movie camera. If you are trying to get a picture of a photo finish of a race, it is almost impossible to take a picture with a still camera. But with a movie camera, you can follow the race across the finish line and then pick the frame showing the photo finish.
Question:
Does getting EUS make a difference? Why get EUS if you have already had a number of other tests?
Answer:
Here's an example of the kind of difference EUS can make: Using EUS, Dr. Snady has a proven 90% accuracy rate for diagnosing potentially removable pancreatic tumors. CT scan accuracy is only about 50% accurate for similar size tumors, the same as flipping a coin.
Even surgery does not provide an accurate diagnosis in about 5% of cases. Using EUS, Dr. Snady has occasionally found malignancies that surgeons have not. That's because surgeons can see only what is visible to the naked eye. With its microscopic focusing ability, EUS can penetrate the layers of the GI tract to detect malignancies that may not otherwise be confirmed until after surgery, when the abnormal tissue that was removed is actually examined with a microscope.
Question:
What good is it to have a more accurate diagnosis?
Answer:
In the past, an accurate diagnosis made little difference for treatment. Since there were few options, the treatment would not have changed with the added information. For example, in cases where localized pancreatic cancer is suspected, it has long been common for patients to undergo diagnostic surgery with the intent that if a tumor is found, it would be removed if possible. In reality, less than half of tumors are removable this way. Unfortunately, even when the tumor is removed at diagnostic or initial surgery, there is little or no improvement in lifespan. In addition, patients are further burdened with an inconvenient and often lengthy recovery period and sometimes hospitalization, so that even if additional treatment is indicated, it cannot be given.
Today, subtle changes in treatment planning may improve patients' quality of life and outcome, many times reducing the time and expense involved in treatment. In cancer cases, Dr. Snady's EUS findings will help determine which of many new treatments to pursue, including new combinations of chemotherapy and radiation therapy that have been shown to dramatically shrink tumors and increase survival. Top surgeons and medical teams know that using these approaches prior to surgical removal makes surgery significantly more effective. Accurate EUS results are critical to using these new approaches to full advantage, because an abnormality can be accurately diagnosed and characterized without surgery. Then, the patient and medical team can make an informed decision as to the best course of action.
Question:
How might treatment change with EUS?
Answer:
In developing a treatment plan, key considerations are whether surgery is
required, and when it would be most effective. When EUS findings indicate that surgery is called for, EUS images, like a map, provide crucial information for the surgeon.
As a result, unproductive or unnecessary surgery is avoided, operating and
recovery time are kept to a minimum, and the best possible patient results
are ensured.
In 1992, a leading medical journal published a report by Dr. Snady showing that the accurate diagnosis arrived at through his EUS findings changed the course of medical treatment for about one-third of patients, and altered treatment plans in about three-fourths of cases. Importantly, patients' overall risk was reduced. Changes typically involved more conservative, less expensive, and less time-consuming treatment, while improving results. Four years after Dr. Snady's report, a joint team of experts from top institutions nationwide were able to attain results similar to his initial findings.
Question:
Does it matter who performs the EUS?
Answer:
It matters for several reasons. To focus on certain areas of the anatomy,
great skill and technical ability is required just to manipulate the EUS
instrument. It takes years of experience and a large caseload to reach a
high level of expertise. The accuracy of results varies widely depending on
the diagnostic skill of the physician, and sub-optimal findings may not provide
dependable direction for guiding treatment. An endosonographer must be
able to document at least an 80% accuracy in diagnosis and staging to
achieve the anticipated 30 - 60% rate of changes in treatment plans.
Dr. Snady's extensive experience and research in sonographic interpretation, along with his clinical skills, allow him an unsurpassed accuracy in diagnosis. He is recognized for his technical ability, his safety record, and his expertise in interpreting sonographic images, and he is often called upon to provide definitive opinions in hard-to-diagnose gastrointestinal (GI)cases. Dr. Snady works closely with your own medical team to discuss treatment options and to help ensure that you receive the best possible care.
Where you have EUS done is also important. Dr. Snady is recognized for having the most experience in the world at performing EUS safely and comfortably in an office setting. Because he does EUS in his own facility, rather than in a teaching hospital, you can be sure that he will personally perform the evaluation. The problems and inconvenience of hospital admissions are avoided, as are the associated hospital fees. The relaxed environment and professional staff have helped achieve a patient satisfaction rate of virtually 100%.
Question:
Why isn't EUS performed by more doctors in the USA?
Answer:
Because EUS combines endoscopy and ultrasound technology, the doctors that use EUS to evaluate patients must be trained and experienced in both. Training in both is not readily available in the USA because here, a gastroenterologist usually performs endoscopy, and a radiologist usually performs ultrasonography. Very few specialists know both endoscopy and ultrasonography. Dr. Snady realized the potential value of EUS and learned the technique when it was just starting to be used in Europe and Japan, where gastroenterologists are typically trained in both disciplines. More U.S. doctors are now being taught EUS, but it takes a minimum of 2 years depending on the number of cases, to achieve an accuracy rate of 75% or greater. If accuracy is less than 75%, the risks of misreading EUS results may outweigh the benefits of having the test.
Question:
Why is EUS better for evaluating the gastrointestinal tract than x-rays?
Answer:
EUS is better than x-ray methods like CT, or other methods such as MRI, particularly when the area affected by the disease is small. Once the diseased area or tumor has already grown large or spread, then other methods can also pick up the disease. One reason EUS is so accurate is that the EUS instrument can be placed right up against the area of disease so that the ultrasound or sound waves used can be very high frequency; much higher in frequency than the sound waves of standard ultrasound used from outside of the body. The precision afforded by these high frequency sound waves provide an image with more detail. (Link available to "When Accuracy Counts"). Another reason is that the intestinal organs are almost always moving so that a picture taken with a "movie camera" (EUS) is better than one taken with a "still camera" (CT Scan, MRI).
Question:
Isn't the best treatment for cancer always surgical removal of a tumor?
Answer:
Although surgical removal of GI tumors seems to make the most sense, in many instances
microscopic remnants of a tumor are left behind because the surgeon cannot see or find
them at the time of the operation. This is particularly true when the tumor has broken
through the intestinal wall or spread to nearby lymph nodes. In such cases, after the
usual 4 to 6 weeks recovery following surgery, a patient may experience a remission for
a few months, only to find that the tumor then progresses at a rate similar to that
prior to surgery. Since there are already many therapeutic options other than surgery
that can help manage symptoms, doctors are discovering ways to improve survival and
quality of life with or even without surgery. For many cancers, new treatments that
shrink tumors before the operation have resulted in dramatic improvements in results. Therefore,
it is more critical than ever to know how advanced a tumor is (tumor stage) before any operation
in order to maximize the chances of successful
treatment. Once patients know their tumor stage, they, with their team of doctors
can define appropriate goals for treatment that can almost always
be achieved. (Link to appropriate papers-)
If you have any additional questions about anything to do with your procedure or your condition, don't hesitate to contact Dr. Snady or any member of our professional staff.