IMAGING

Issues, controversies, and clinical utility of combined PET/CT imaging: what is the interpreting physician facing?
Blodgett TM, Casagranda B, Townsend DW, Meltzer CC
Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
AJR Am J Roentgenol. 2005; 184 (5 Suppl): S138-45

• Objective: This article identifies the most commonly encountered issues of combined PET/CT and shows the wide variability in perceived possible solutions to these issues. This article will serve as a catalyst to stimulate discussion between experts in both radiology and nuclear medicine.
• Conclusion: Combining a PET tomography and CT scanner into a single unit amounts to advantages that are not merely additive, but synergistic. Even PET/CT skeptics will embrace the technology after becoming acquainted with the possibilities and will accept the reality that there is no return to PET only.
  
  
• Editorial Comment
  Combined PET/CT scanners are rapidly becoming the new standard in oncologic imaging because provides information on the morphology and function of tumors in one examination. This technology incorporates a multislice helical CT (16 or more channels) and high-resolution PET scanners. The information offered by this method has superior diagnostic capabilities and are very useful for staging neoplasms and radiation therapy planning. This an excellent article that discusses with clarity all very important issues related to the application of this new technology. Several interesting issues are discussed such as protocols of examination, how and by whom the scans are interpreted, the variability in reporting methods, where is the best place for the equipment and many other operational, educational and legal issues. The authors emphasizes that at this stage, the best indications of PET/CT are for staging patients with lymphoma, lung and colorectal cancer and for restaging patients who have undergone extensive surgery or who have had significant levels of radiation, both of which tend to distort normal anatomy and cause inflammatory changes (head and neck, colorectal, thyroid and ovarian cancer, and lymphoma). Although at this stage the role of PET/CT in the evaluation of urological malignancies is limited (detection of metastases and recurrences of renal cell cancer, identification of vital tumor tissue after chemotherapy of seminomatous germ cell tumors and detection of nodal metastases from bladder cancer), we still strong recommend the reading of this manuscript which will help the urologist to understand the several complex issues related to the application of this technology.

Dr. Adilson Prando
Chief, Department of Radiology
Vera Cruz Hospital
Campinas, São Paulo, Brazil