PITTSBURGH, August 27, 1998 — Doctors’ ability to see into the body for diagnosis and planning treatment may take a big step forward based on technology now under study at the University of Pittsburgh Medical Center (UPMC). By performing both PET (Positron Emission Tomography) and CT (Computer-assisted x-ray Tomography) studies sequentially on the same unit, anatomical and functional information is combined in a single image. A small pilot series of patients is currently being evaluated using a prototype of the new technology.
"Combining PET and CT scanning is a revolutionary breakthrough," says Richard L. Baron, M.D., professor of radiology, University of Pittsburgh School of Medicine and chairman, department of radiology, UPMC. "This new technology not only provides far more information about the state of disease processes, but also reduces the need for invasive diagnostic procedures, such as biopsies, and improves the accuracy of needed procedures by pinpointing precise sites for testing."
Advances in radiology over the past quarter century have provided doctors with alternative methods of seeing inside the body. CT scanning, a system of multiple X-ray data assembled by computer, that was developed in 1972, provides much more accurate and precise images of internal anatomy than even the most advanced single-image X-rays. PET imaging provides detailed information on biochemical processes that physicians use as markers of disease. Until now, correlating these sets of data – showing exactly where in the body diseases exist – has been frustrated by technical difficulty of superimposing these images. Many times the systems in use are incompatible. Additional problems have been the lack of precise points of reference and shifting of the internal organs during the time lapse between images.
The PET/CT scanner will not be available elsewhere for at least a year to a year and a half," says David Townsend, Ph.D., UPMC senior PET physicist, associate professor of radiology, and the chief investigator of this study. Dr. Townsend is an internationally known researcher who has advanced PET technology for more than a decade. He proposed development of the PET/CT scanner in 1995, after working with colleagues in Europe to develop the lower-cost rotating PET scanner. His collaboration with CTI PET Systems, Inc., Knoxville, TN (which pioneered every major commercial advance in PET imaging technology), yielded the prototype now in trial at UPMC.
Important developments in image reconstruction by Dr. Townsend and Paul E. Kinahan, Ph.D., PET physicist and assistant professor, department of radiology, have greatly improved the quality of images from the dual scanner by taking into account patient variation when processing data. Other software refinements resulting from this project will increase the quality of images each technology can produce even when used separately.
"The trial of the first PET/CT scanner at UPMC is designed to validate this new technique through engineering, scientific and software refinements. We are current seeking clinical validation in primarily oncological applications," says Dr. Townsend. "A small pilot series of patients with known cancer masses are being evaluated with the new PET/CT system. The resulting images are being compared with ones taken from separate PET and CT scanners to evaluate the improvement in diagnostic information."
Several patients with pancreatic cancers have been part of the pilot study of the PET/CT scanner. "The information the PET/CT scanner provides is remarkable," says Adam Slivka, M.D., Ph.D., assistant professor of gastroenterology and hepatology, University of Pittsburgh Cancer Institute and co-director, UPMC Center for Pancreatic Diseases.
Dr. Slivka went on to say, "One of the major difficulties in helping patients with pancreatic cancers is that by the time they present with symptoms of the disease, it has already progressed to the point where it is very difficult to treat and cure. Although studies remain to be done that will determine PET/CT's diagnostic accuracy, early experience with this new scanning technology suggests it will assist in diagnosing and staging pancreatic cancer and may become a valuable screening tool. Earlier detection of pancreatic cancer will increase the chances of successful curative therapies."
CTI PET Systems senior vice president and technology director Ronald Nutt, Ph.D., notes that the combined PET/CT scanner is a development of CTI PET Systems, which is a joint venture between Siemens and CTI, Inc., under the umbrella of CPS. CPS is the joint venture formed in 1988 between Siemens Medical Systems, Inc., and CTI, Inc. CPS develops, manufactures and provides marketing for PET tomographs worldwide and provides sales and product services in the U.S. CTI, Inc., the world leader in PET products and services, is dedicated to making positron imaging a widely used primary clinical modality. CTI's product line includes ECAT tomographs, RDS cyclotrons, and LSO, a new scintillator material for photon detection over a wide range of energies. CTI also operates PET pharmaceutical distribution centers through its PETNet Pharmaceutical Services, LLC joint venture. CTI was founded in 1983 and employs about 200 people worldwide.
Development of the PET/CT was facilitated through an $843,000 grant from the National Cancer Institute.
UPMC’s department of radiology received a consulting fee from CTI PET Systems for intellectual contributions Dr. Townsend made to the development of the new system.