March 31, 2000

The Department of Radiology, working with MGH administration, acquired a new positron emission tomography (PET) camera last summer to step up the hospital's use of the technology for patient care. The newest PET camera is temporarily housed in a medical trailer located across the street from the Massachusetts Eye and Ear Infirmary until renovations are completed on White 2.

PET detects changes in the physical size or structure of internal organs as other imaging technologies do, but PET also detects changes in cellular function. Because these functional changes may take place before physical changes occur, PET can provide more information to make an earlier diagnosis of a disease.

The MGH had been the only hospital in New England to own a PET scanner for about 20 years (Dana-Farber Cancer Institute just installed one). Recently new applications for PET have been approved by the Health Care Financing Administration (HCFA), resulting in the need for a second scanner at the MGH. The HCFA approvals allow the cost of the applications to be reimbursed by Medicare.

"This modality is fantastic," says John Hergenrother, RTN, of Nuclear Medicine. "You can see things that you can't with other modalities, such as MRI or CT scanning. This capability can help physicians make quicker decisions about treatment and also can help avoid more invasive exams or surgery."

Because of the advantages of PET scans, the technique can be used in the early detection of diseases in which CT and standard MRI can detect only structural changes that occur later in the disease process.

According to Hergenrother, PET has proved to be accurate in detecting many neurological and cardiac disorders as well as some cancers in their early asymptomatic stages. Studies have shown that PET provides 10 to 20 percent more accurate detection over conventional approaches.

PET also has proved useful in the assessment of the progress of a disease — a process called staging. For example, when a cancer patient is treated with chemotherapy, PET can detect whether the chemotherapy is affecting the tumor.

HCFA has approved five applications for PET scan use — two for the staging and evaluation of lung cancer in addition to those for colorectal cancer, melanoma and Hodgkins and non-Hodgkins lymphomas. PET also has demonstrated effectiveness in detecting ovarian, breast, pancreatic, thyroid and musculoskeletal cancers and can be useful for diagnosing conditions of the brain such as seizure disorders, stroke and tumors. These applications currently are under review for reimbursement by HCFA.

"The HCFA approvals are encouraging," says George Desko of Radiology. "There is a growing interest among clinicians across the country to examine the use of PET more closely and evaluate the possibilities."

For more information or to schedule a PET scan, call 6-8367.

From left, Hergenrother demonstrates the second PET scanner
with Paul Roy, RTN, an MGH Nuclear Medicine technologist.