Body Image Improves With PET Scanners
by August 4, 2003 12:00 am 107 views
Advanced imaging technology now being used in Northwest Arkansas is giving doctors their best view yet of the inside of the body. Instead of imaging that detects changes in physical size or structure of internal organs, Positron Emission Tomography detects changes in cellular function.
PET Scanners range in price from $1.5 million-$3 million and often prove too costly for hospitals, especially considering possible advancements in technology that could instantly outdate such equipment. Northwest Arkansas doctors are now using the high-tech tools to get detailed peaks inside the body with PET units at a Fayetteville oncology clinic and, more recently, a Fort Smith hospital.
For two-thirds of the patients who underwent a PET scan in a recent study, the stage of their cancer diagnosis changed, said Kris Gast, radiation oncologist for Fort Smith Radiation Oncology. Forty percent of those diagnosis changes were cancer upstages, she pointed out.
“Some of those patients maybe shouldn’t have had any major treatments,” Gast said.
The new medical imaging technology allows doctors to see three-dimensional images of the body as well as actual images of metabolic functions within the body. The PET Scanner is not only a tool for cancer diagnosis and treatment planning, but it also allows doctors to view images of heart and brain functions.
It uses nuclear technology to scan cross sections of the body.
A PET scan can determine the difference between recurrent, active tumor growth and masses of dead tissue in cancer patients. Epilepsy, stroke, dementia, brain tumors and coronary artery disease are among other diseases doctors are using it to diagnose.
Sparks Goes Mobile
Sparks Regional Medical Center is the first hospital in the region to offer PET scans. Sparks began offering PET scans in June through a mobile imaging service on a contract basis. Alliance Imaging, based in Dallas, has 40 PET units on semi-tractor trailers that serve 170 customers throughout the nation.
“It adds a tremendous amount in caring for our cancer patients,” Gast said. “We convinced the hospital that it’s a tool we needed to complement our care in regard to staging. It’s a major tool in terms of staging, restaging and evaluating response to therapies for cancer patients.”
One young breast cancer patient of Gast’s learned the cancer hadn’t spread and she was able to proceed with her final treatments without concern. Gast said several other patients have had their stage of cancer adjusted after she viewed the PET scan results.
By being able to view how organs with cancer are actually reacting to various treatments, Gast said she’s better able to determine the best course of action for additional treatment.
Doctors have to “pigeon hole” the patient in a stage of cancer and then use varying treatment options for each stage, Gast explained. If the correct stage isn’t diagnosed, then the doctor might prescribe the wrong treatment, she said.
The majority of patients who will use the scanner are cancer patients, but Gast said it’s also useful in heart, stroke and dementia patients. Lung, colorectal, esophageal, melanoma, breast, head and neck, and lymphoma are among the cancers for which doctors have typically prescribed PET scans. Thyroid cancer patients are more recently benefiting from the new imaging.
Still Considered New
Kathie Parker, administrator at Highlands Oncology Group in Fayetteville, said PET scans have been used for about 10 years, but the imaging technology is still struggling to prove itself in some ways. Highlands has had its PET Scanner for about two and a half years. It’s used strictly for cancer patients, but it’s sometimes difficult to get insurance companies to cover it.
Gast said her patients traveled to Fayetteville for scanning at the clinic before Sparks began contracting for the mobile imaging service. The drive isn’t that long, but patients who are elderly and not feeling well often declined to make the trip, she said.
Sparks is also using the mobile scanner for treatment of stroke and heart patients, although it isn’t used as often. Gast said the benefits for cancer patients are great, but heart and stroke patients haven’t yet realized as many benefits.
According to a brochure from GE Medical Systems, which produces the PET Scanner, the technology can measure blood flow in the heart for detecting coronary artery disease, helping doctors determine if a patient will benefit from expensive and highly invasive medical procedures.
Highlands’ PET Scanner isn’t set up to do scans for heart disease or brain function, although it could, Parker said.
“One of the reasons we wanted it was for staging of lung cancer,” Parker said.
The six doctors at Highlands Oncology are better able to treat lung cancer patients if they know in exactly what stage of cancer they are. Before this technology became available, it was much harder to determine, she said.
Highlands was the first private oncology unit in the United States to get its own PET Scanner, Parker said. It cost about $1.5 million and likely hasn’t paid for itself yet in patient fees, but has been well worth the investment, she said. Highlands charges $3,400 for a scan.
The fee is sometimes difficult to get covered by an insurance company, and Highlands now confirms insurance coverage before performing a scan, because of the expense. In many cases, the PET scan will save money for procedures patients don’t really need, but doctors can’t tell without the technology, Parker said. As the technology becomes more accepted it will likely be used more for early diagnosis, she predicted.
“Medicare allows for certain coverages. You have to have a certain diagnosis to be covered,” she said.
Breast cancer and heart muscle scans are now covered by Medicare but were considered experimental previously.
A Little Rock hospital had the closest PET Scanner before Highlands bought its own.
The Process
Jamie Gladson, PET specialist at Highlands, said it takes almost two hours to perform a PET scan. She often scans before and after cancer treatments to determine how the tumor is responding.
Patients are first injected with a radiopharmaceutical that’s allowed to be absorbed by the body for about 40 minutes. Then they are asked to lay on a padded table that is raised and moved slowly through the ring-shaped scanner as images of the body are scanned. It takes about an hour for the scanning, but it can vary, Gladson said.
The radiation received is equivalent to having a couple of chest X-rays and is short-lived in the system.
Gast explained that the radiopharmaceutical attaches itself to glucose in the body and allows the scanner to get images of how the cells are utilizing the nutrients.
“Cancer takes up more of the glucose, and the PET camera detects increased uptake in spots,” Gast said. “We scan from head to toe; any spots taking up more glucose show up.”
Sparks had originally contracted to have the PET unit available every other Friday but within weeks had changed the contract to offer it weekly.