"Combining the functional information of PET and the anatomic information of CT is a sophisticated technological accomplishment. It is revolutionizing the diagnosis and treatment of cancer."
Richard D. Newman MD
Chairman, Department of Radiology
"PET takes the diagnosis and treatment of cancer to a whole new level."
Frederick P. Smith MD
Sibley's commitment to cancer diagnosis and treatment continues with acquisition of the revolutionary PET scanner made by GE Medical Systems. PET is the acknowledged gold standard for medical, surgical and radiation oncology. It enables physicians to diagnose cancer early, treat it with extraordinary precision and monitor treatment efficacy quickly and accurately. It will support the medically sophisticated cancer care here at Sibley and it will also be available as a resource to physicians throughout the region.
In addition to cancer care, PET is considered the gold standard for assessing whether a heart muscle is viable for bypass surgery. It can reveal whether the muscle is merely "asleep" or "dead." PET is also used in the diagnosis of and treatment planning for intractable seizure disorders—cases where seizures do not respond to medication.
The How and Why of PET
Both PET and CT enable physicians to "see inside" the body. Computed Tomography (CT) uses radiation to capture highly detailed, high-resolution anatomic information. It enables physicians to identify lesions and masses that may be malignant.
On the other hand, Positron Emission Tomography (PET) reveals metabolic function at the cellular level. Changes in cell processing are the first indications of cancer and they are evident long before structural abnormalities develop. Since PET is highly sensitive to even small changes in cell function, it is invaluable in the early diagnosis of cancer.
In order to take advantage of both the anatomic detail offered by CT and the specificity of PET, some physicians have been working with a CT from one machine and a PET scan from another machine. By considering the information from both sets of images, the physician makes a judgment about whether a mass (as indicated by the CT scan) reveals a high level of metabolic activity (as revealed by the PET scan). Doing this well can be difficult and sometimes impossible because frequently, images from one machine do not align with images from another.
A PET/CT scan performed at one point in time on a single machine provides a fused image that precisely places the information about cellular activity in an accurate anatomical context.
According to Frederick P. Smith MD, a respected Washington-area medical oncologist, PET takes the diagnosis and treatment of cancer to a new level. "We no longer have to make assumptions about what is cancer and what is not. We know for sure and we know early on. We do not have to estimate placement. We can pinpoint it with absolute certainty. This specificity and accuracy lets us define a targeted treatment plan with a very high level of confidence about its potential effectiveness."
Understanding the Technology
PET relies on a tracer called18FDG. It is a combination of a positron emitter and a glucose analog. Tumor cells take up this tagged glucose look-alike more avidly than other cells and they also hold it more tenaciously. The result is that malignant lesions—even as small as a few millimeters—are dramatically highlighted in a PET scan. With a PET, these "hot" areas are presented in an accurate anatomic context.
PET is a proven tool in the treatment and diagnosis of the following:
- Lung Cancer
- Colon Cancer
- Esophageal Cancer
- Breast Cancer
- Pulmonary Nodules
- Coronary Artery Disease
- Intractable Seizure