Mass General Hospital - Department of Radiology - PET

The first PET scans, Positron Emission Tomography, were measured at MGH, and the department continues to be involved in cutting edge research. PET measures radioactive tracers injected into the body. One of the most important PET tracers is a radioactive form of glucose, which is used for energy by living cells. "Cancer cells are typically inefficient, and require more glucose than surrounding cells," explains department head Alan Fischman, MD "Because they use more of the radioactive glucose, cancer cells emit more radioactivity, which shows up on the PET scan. PET scans are also used to study the perfusion of blood in the heart, which helped determine the condition of heart muscle, the and the perfusion of blood in the brain, which helps find sites of seizure activity."

Altropane
The department pioneered the use of Altropane to diagnose and study Parkinson’s Disease, a common neurodegenerative disorder. Altropane is a radioactive form of cocaine that binds to certain dopamine-transporter molecules. It aids in the diagnosis of Parkinson’s disease by visualizing the degree of nerve loss. Altropane images might also be used to track the success of experimental treatments for Parkinson’s and to find people who are presymptomatic, in an effort to learn more about the causes and origins of the disease.

Research
The department is helping with a number of studies on the human brain. PET scans are used for functional imaging of brain activity, a process developed at MGH. The patient inhales a radioactive tracer that reflects blood flow and then performs an action. Scans acquired before and after the action show where the change in blood flow occurs, which indicates what part(s) of the brain are involved in performing the action. Functional imaging has moved into clinical use, but continues to remain a critical tool for basic brain research.

The department is participating in FDA trials of radioactive antibodies for the treatment of cancers. The trials include agents designed to treat ovarian cancer, and non-Hodgkin’s lymphoma. The department also works with pharmaceutical companies to find out where drugs go in the body and in what concentrations.