Advanced Technology PET/CT Scanner Becomes Operational at The Queen's Medical Center

Sandi Kwee, MD, at the PET/CT scanner computer console.

A Phillips PET/CT scanner, the most advanced available today, became operational the week before last at the Hamamatsu/Queen’s PET Imaging Center, the only hospital based facility in Hawaii have one. The Queen’s Medical Center has the largest and most active nuclear medicine department in Hawaii, combining both clinical nuclear medicine and research.

Both PET (Positron Emission Tomography) and CT (Computerized Tomography) are well established diagnostic imaging tools that physicians use to locate cancer before making treatment recommendations. Both have strengths and limitations. In the past, PET and CT scans were done separately, presenting difficulties in matching the scans due to slightly differing body positions. However, when PET and CT scans are done together and fused, the combined image provides a powerful diagnostic tool that gives complete information on cancer location (structural) and metabolism (physiological).

A patient is first scanned by the CT portion of the scanner and pictures of the body’s internal structures are created, along with the location, size, shape and mass of tumors. The patient, who has been previously injected with a glucose/radioisotope tracer, is then scanned by the PET portion of the scanner. PET images show metabolic hot spots, which often indicate rapidly growing tumors (cancer cells consume glucose faster than normal or benign tissue). Radioisotopes are manufactured at the Liholiho Cyclotron Building at Queen's.

Scheduler Josephine Nable (front) peers through the CT scanner, while PET assistant Lisa Martin looks through the PET scanner at the rear.

The CT and PET images match up perfectly, giving physicians more detailed and accurate information than ever before. In some instances, the CT scan will show that the structure of a tumor has not changed from a previous scan, but the PET will detect where the tumor is growing, indicating that treatment should cover a larger area. The majority of Hamamatsu/Queen’s patients are oncology patients. The PET/CT scanner is used to determine the stage of cancer or the restaging of cancer in response to chemotherapy and/or radiation treatment. The benefits of combined PET/CT scans include earlier diagnosis, accurate staging and localization and precise treatment and monitoring. The system is also capable of doing heart and brain scans.