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PET scans locate tumors Mail Tribune/Drew Fleming Sherry Walker operates the new positron emission tomography (PET) scanner at Rogue Valley Medical Center. The machines give physicians more precise information about the size and location of tumors and display the information in three dimensions on a computer screen. Diagnostic scanning technology has arrived at Rogue Valley hospitals By Bill Kettler A few drops of sugar water help physicians track the course of cancer. It�s not ordinary sugar water, of course. It�s tagged with a radioactive tracer that lets doctors see tumors without invasive surgery. "We can pinpoint where a tumor is in the body," Sherry Walker said as she explained a procedure called positron emission tomography. PET scanners have been used in big-city hospitals for several years, but the technology has only recently come to smaller communities such as the Rogue Valley. How it works Positron emission tomography locates tumors by distributing radioactive fluorine in a patient�s body, but the procedure involves minimal radiation exposure for patients because the material deteriorates quickly. The radioactive fluorine has such a short life that it must be flown to Medford from the Seattle laboratory where it is manufactured, then used quickly before it deteriorates. "As for radiation safety, there�s much less (radiation exposure for a patient) than most X-ray procedures," said Sherry Walker, a nuclear medicine technologist who operates the new PET scanner at Rogue Valley Medical Center. Walker said the radioactivity leaves a patient�s body quickly after the PET scan is finished. It passes to the kidneys and the bladder and is excreted in a patient�s urine. Walker, a nuclear medicine technologist, operates a new PET scanner at Rogue Valley Medical Center, where about 20 scans have been performed since the equipment was installed in November. Providence Medford Medical Center has installed equipment that will also perform diagnostic scans and expects to offer the service within 60 days. PET scans give doctors a whole new level of information about tumors without having to perform surgery. The scans reveal tumors as small as 1 centimeter (about the size of a raspberry) and they show doctors where the disease has spread. Physicians use the information to decide whether the cancer should be attacked with surgery, chemotherapy, radiation or some mixture of the three. "It really helps us make sound decisions about how we�re going to treat people with cancer," said Dr. R. C. Sinnott, a radiologist who has been using the new technology. PET scans use cancer cells� appetite for sugar to ferret out tumors. All human cells consume glucose and other simple sugars, but cancer cells metabolize glucose faster than healthy cells. When a patient is injected with the tagged sugar solution, cancer cells grab more of it than healthy cells. The cancer cells pick up the radioactive tracer, too. A sensitive scanner sees the tracers and converts the information into a three-dimensional picture on a computer screen. Tumors show up as bright "hot spots." Walker can create a precise record of each tumor�s location and size by looking at the images from top to bottom, side to side, or back to front. "That allows us to detect tumors at a very early stage," said John Mayben, another nuclear medicine technologist who operates RVMC�s PET scanner. The procedure is too expensive ($4,000) to use as a cancer screening tool, but it saves money when it�s used to evaluate patients already diagnosed with cancer. Sinnott noted that chest surgery for a lung-cancer patient can cost more than $20,000 and leave a patient in pain for months. A PET scan can tell doctors whether surgery is warranted, and perhaps save a patient months of recovery. Sinnott said cost-saving advantages have made PET scans increasingly attractive to insurance companies. Doctors like its ability to uncover tumors that escape detection under other diagnostic tools. "In two of our first 20 cases, we have found disease where it wasn�t suspected from a CT scan," he said. The procedure requires patients to lie motionless for 90 minutes while two recording heads rotate slowly around their bodies. Patients must fast prior to the test, but at least one local woman said it was easier to endure than other diagnostic scans. "I just really didn�t mind it," said Laurie Ludwig, a Merlin woman undergoing treatment for melanoma. "The thing makes a little bit of noise � a series of clicks and hums � but I found it kind of calming in a way that almost puts you to sleep. "I was a little bit nervous going in," she said. "I had already had a CT scan and an MRI and I didn�t enjoy either of those. "When I went in for an MRI, it sounded like somebody had a sledgehammer and they were beating it all around me for 45 minutes." Ludwig even dozed off during her PET scan, lulled by the scanner�s mechanical rhythms. "You wouldn�t fall asleep during an MRI," she said. Reach reporter Bill Kettler at 776-4492, or e-mail [email protected] Mail Tribune Home | Ottaway Newspapers, Inc. | Dow Jones & Co., Inc. | Privacy | Contact Us Copyright � 2000 Mail Tribune, Inc.