Figure 1. A client taking advantage of educational material via a Mobile Breast Care Center workstation.
Figure 2. Moble Breast Care Center.
As strange as it may seem, the Serbian-Croatian conflict in Bosnia and the detection of breast cancer share a common element: telemedicine. According to U.S. Army personnel, one of the most successful deployments in Bosnia was a teleradiology clinic, complete with satellite communications, medical diagnostics equipment, and trained medical technicians. But instead of bringing every type of medical specialist to Bosnia, diagnostic information was sent via satellite to doctors back in the States, where they formed opinions and suggested the best treatments. More than 100,000 x-rays of injured soldiers and civilians were sent from Bosnia to radiologists in Germany and Walter Reed hospital through this program.
While U.S. cities rarely resemble a war-torn landscape, there are many areas, from the isolated mountains of Tennessee to the remotest regions of Alaska, where medical expertise is almost nonexistent. The fast-developing field of telemedicine can bring cutting-edge diagnostics and medical expertise to these isolated and/or impoverished areas. Thanks to advances in telecommunications, information systems, and digital imaging equipment, the day when the doctor is always in may not be that far away.
Spreading the word about breast cancer
Although telemedicine techniques are being developed around the world, according to many experts the U.S. Army's Medical Research and Material Command (MRMC; Frederick, MD) is a stronghold for the creation of mobile, hardy communication systems and medical expertise. Therefore, when the Public Health Service's Office on Women's Health and the National Cancer Institute looked for a way to bring advanced breast cancer diagnosis, education, and treatment facilities to isolated areas, they looked to the U.S. Army and Fort Deitrick (Frederick, MD).
The goals were ambitious: develop a mobile unit that could bring breast cancer education, evaluation, and diagnosis to the most isolated areas; bring radiologists to the patient without removing the doctor from his or her hospital and do this regardless of the information infrastructure; raise women's awareness, while providing a way to definitively diagnose potential cancer survivors before it's too late; and do all this in an expedient fashion that will not discourage follow-up visits or patient participation.
Trying to fit all that into a single vehicle proved an enormous job. The Mobile Breast Care Center barely fits in an extra-wide semi-tractor trailer. Expandable sides fold out from the trailer to form a breast cancer clinic on wheels that measures 53 x 32 feet.
The mobile center is divided into two main sections -- the clinical and education side and the imaging side. Moveable walls inside the center allow the crew to reconfigure the shape of the education and pre-patient screening sections. "One person can change the setup so that you can have one large area for teleconferencing or teaching a class, or five individual examining rooms, plus two waiting rooms and an imaging room," explained Major Greg Mogel, project leader for the mobile center at MRMC.
As the women enter the building they go through a typical health provider intake procedure to collect biographical and other patient data. "When we begin patient trials, we hope to find out exactly what these [oftentimes underserved] people need. Information on smoking, hypertension, blood sugar analysis, etc." Added Mogel. "We want to make a platform that can do all those things."
After this, the women have access to several different types of educational material, including brochures and online access through seven PC workstations. These workstations are connected to a 100-Mb ethernet LAN that runs throughout the center. Each work station also has a small camera for video teleconferencing where patients can ask specialists about their medical conditions or just get more information. Patient records can also be sent via the same PCP internet protocol, assuming health care providers use this standard.
When her turn comes, the patient enters the clinical portion of the center for physical examinations, and possibly imaging.
Mogel and his associates realized that one of the most ambitious mobile breast care centers was developed several years ago in the UK. That system, which used film mammograms, could examine approximately 15 women an hour. "We realized early that throughput was a critical issue to the success or lack of success for the program. Our goal was to use a completely different paradigm."
That paradigm shift has its source in a new digital x-ray mammographic imaging system developed by GE Corp. R&D (See sidebar). The system allows the mobile care center to transmit, almost instantly, the large 40-MB x-ray images to waiting radiologists. The x-ray information is supplemented by conventional ultrasound equipment also furnished by GE.
Confirmation of suspicious findings on x-rays can be carried out using ultrasound. An ulttrasound performed with an external camera would allow the remote radiologist to see where the technician places the ultrasound transducer.
Depending on the final configuration, images can be sent via the local ethernet to an asynchronous transmission mode telecommunications closet designed and installed by GETT Communications. The closet acts as the gateway for all information coming in or out of the center.
According to Mogel, meeting the bandwidth requirements of video teleconferencing, internet, and audio communications is not terribly hard since each represents around 384 kb/s of data. But when the mammograms are thrown into the equation, bandwidth becomes an issue. "No one has got the nerve to look an attorney in the eye and say, 'Yes, I compressed that [digital mammogram] by a factor of a 100.' And since we're not transmitting overnight and need to do this in real time, we can't take three hours to do it," Mogel said.
Because the center is designed as a prototype test vehicle, it incorporates almost every kind of telecommunication technology from Ku-band satellite hookups to connections for terrestrial communication lines. Breaking down and setting up satellite communications is costly and time consuming "unless you want to carry a telecommunications engineer around with you everywhere you go," Mogel said. "So we've reinforced the lesson that, if we had to choose between the many different modalities, a fixed wireless solution would be the best."
Although wireless may be the solution for the future, the center's first clinical trial -- held in December at Keller Army Community Hospital at the West Point Army Academy campus -- will use two T1 terrestrial telecommunication lines: one for image transmission and a second to handle the internet, audio, and visual telecommunications.
As part of the trial, 50 women will first undergo film mammograms and inspection at the hospital. They will then go out to the mobile center for another examination and a digital imaging session. These images will be compared with the conventional films for accuracy as a precursor to larger clinical trials for the digital mammography system. The trial will also allow the center's crew to work out kinks in the patient intake, counseling, and education procedures.
Into the future
Although the center offers women almost immediate answers, it does not offer every service. In the event that a potentially tumorous region is identified, the patient would still have to travel to a hospital for biopsy and treatment. That could change, however, because the ultrasound examination room has been designed for easy conversion into an invasive diagnostic room where biopsies could be carried out, according to Mogel.
This month, Mogel and his associates will begin to learn just how effective the center, and its digital x-ray mammography equipment, promise to be. This learning experience is neither the first nor the last step in the development of a mobile breast cancer center, according to Mogel. Many questions remain about the imaging equipment, image handling, and telecommunications systems.
Digital mammography awaits FDA approval
General Electric officials expect commercial deployment of a new digital x-ray mammographic device to happen later this year following Food and Drug Administration approval. The device uses a large, 7 x 9-in. silicon detector to transfer x-ray energy into electrical signals. According to Maj. Greg Mogel of the U.S. Army Medical Research and Materials Command (MRMC), the device offers 100 µm resolution. A typical mammogram incorporates four images of 8 to 10 MB per image, resulting in 40-MB digital images for a complete file. Film-based mammograms are measured in line-pairs per millimeter. According to Mogel, researchers are still discussing the appropriate resolution for a digital mammogram. Possible standards range from 25 to 200 µm with particular interest at 50- and 100-µm resolution.
In addition to reducing the patient's wait for an answer, GE representatives say that digital x-ray mammography offers several advantages compared with film systems. At the radiologist's command, the system can increase the image's contrast to reveal hidden details or enlarge portions of the image.
GE's digital mammography system began clinical trials at several U.S. hospitals in 1997. Of particular interest to telemedicine, another study conducted in conjunction with the National Cancer Institute and Massachusetts General Hospital in Boston shows that digital mammograms do not lose quality with satellite transmission. During the study, 96,000 archived digital mammograms were transmitted, under varying weather conditions, between GE's research and development center in Schenectady, NY and the hospital with no noticeable losses.
R. Winn Hardin
R. Winn Hardin is a science and technology writer based in Fairbury, NE.