In non-small cell lung cancer (NSCLC), the determination of stage is important in terms of therapeutic and prognostic implications. Careful initial diagnostic evaluation to define the location and to determine the extent of primary and metastatic tumor involvement is critical for the appropriate care of patients. The stage of disease is based on a combination of clinical factors (i.e., physical examination, radiology, and laboratory studies) and pathological factors (i.e., biopsy of lymph nodes, bronchoscopy, mediastinoscopy, or anterior mediastinotomy). CT of the chest is usually considered sufficient for body staging. The CT scan should extend inferiorly to include the liver and adrenal glands and this is the NCCN recommendation.
Patients at risk for brain metastases may be staged with CT or MRI scans. One study randomly assigned 332 patients with potentially operable NSCLC but without neurological symptoms to brain CT or MRI imaging to detect occult brain metastasis before lung surgery. Whether the improved detection rate of MRI translates into improved outcome remains unknown and CT of thte brain is considered fully acceptable. For stage III it is certainly the standard of care.
For PET scanning, see here
Webb WR, Gatsonis C, Zerhouni EA, et al.: CT and MR imaging in staging non-small cell bronchogenic carcinoma: report of the Radiologic Diagnostic Oncology Group. Radiology 178 (3): 705-13, 1991.
Toloza EM, Harpole L, McCrory DC: Noninvasive staging of non-small cell lung cancer: a review of the current evidence. Chest 123 (1 Suppl): 137S-146S, 2003.
Gould MK, Kuschner WG, Rydzak CE, et al.: Test performance of positron emission tomography and computed tomography for mediastinal staging in patients with non-small-cell lung cancer: a meta-analysis. Ann Intern Med 139 (11): 879-92, 2003.