Integrated PET-CT: evidence-based review of oncology indications.

Over the past few years, positron-emission tomography (PET) has been increasingly used in oncology. More recently, the fusion of the functional imaging provided by PET with the anatomic information of computed tomography (CT) has resulted in a powerful new imaging tool. In practice, the PET-CT image fusion can be done visually, with the help of special software, or through hardware incorporating both PET and CT. We performed a review of disease-specific studies using integrated PET-CT or PET-CT with visual or software fusion and found that PET-CT offers a significant benefit in improving the diagnosis, staging, and therapeutic monitoring of patients with cancer. Integrated PET-CT improves characterization of equivocal lesions and decreases intraobserver variability; it also has the potential to significantly affect treatment planning by guiding biopsies and surgical interventions, defining target volumes for radiation therapy fields, and monitoring response to treatment. More promising clinical applications will likely be possible with other fluorine-18-based isotopes.