PET/CT fusion scan in lung cancer: current recommendations and innovations.

Combined fluorodeoxyglucose-positron emission tomography (PET)/ computed tomography (CT) imaging has the potential to become the new standard imaging modality for the staging and restaging of patients with lung cancer. PET/CT is superior to PET alone, CT alone, and visual correlation of both techniques separately. In particular, it improves T3 and T4 staging and delineation of tumors associated with atelectasis. CT contrast media enhancement is probably only still needed when a substantial mediastinal tumor component is present and delineation of tumor from vascular structures is relevant. PET/CT is very accurate in detecting mediastinal nodal disease, but false-positive results are sufficiently frequent to require sampling in some positive cases. Whole-body PET/CT is the most sensitive technique for detecting extracranial metastatic disease, unexpected additional primary malignancies, and recurrence. Innovations include therapy monitoring, prognostic information, evaluation of small-cell lung cancer, its use for radiotherapy planning, and four-dimensional respiratory gating acquisition.