Positron emission tomography in nonsmall cell lung cancer

Positron emission tomography (PET) has become a major adjunct to structural imaging for nonsmall cell lung cancer. Established indications are the differential diagnosis of lung nodules, as well as mediastinal lymph node and extrathoracic staging.

More details for small or faint pulmonary nodules became available--information of interest in the era of lung cancer screening trials, in which PET might help to reduce unwanted invasive procedures for benign findings. The strength of PET in mediastinal staging (its high negative predictive value) was confirmed in a randomized study, in which PET reduced the number of invasive procedures without loss of accuracy in staging. Isolated positive lesions that are decisive for radical compared with palliative treatment should be confirmed by other tests, as they may be benign or due to second primary cancer. PET with integrated computed tomography (CT) may guide modern radiotherapy, by improving radiation fields. Integrated PET-CT is a promising tool in the indication for surgery in stage IIIA-N2 patients after induction treatment. Predictive values for lymph node downstaging become in acceptable ranges and PET response in the primary tumor could be clearly linked to pathologic response and survival.

In recent years, PET has seen further refinements in established indications and definition of new indications.