Positron emission tomography: new hope for early detection of recurrent brain tumors

Positron emission tomography (PET), the newest of the nuclear medicine imaging instruments, is now being used for diagnosis in 20 clinical sites in the United States. Recent approval of third-party reimbursement for PET scans for selected illnesses has set the precedence for wider clinical applications of this advanced diagnostic tool. Most practical of the newest applications of PET in the US is in early detection of recurrent brain tumors. Early detection not only saves lives, but also may save thousands of dollars in unnecessary tests, treatments, and surgeries. PET has two basic advantages over computerized tomography (CT) scans and magnetic resonance imaging (MRI). First, PET creates vastly superior images of metabolic activity, making possible more accurate and detailed diagnoses. Secondly, PET causes very low radiation absorption due to the volatile nature of the radioisotopes used. The rapidly increasing use of PET in clinical situations requires the nurse to become aware of its basic principles and applications, as well as the nursing care involved when a client is scheduled for a PET scan. This study serves to explain basic physical principles employed by PET. The historical development of PET and the comparison of PET with x-ray, CT, and MRI are reviewed. The article concludes with a discussion of future oncologic applications and the latest research developments in clinical use of PET scans.