Departments: Interventional Pulmonology in Other Journals
Staging of Non–Small-Cell Lung Cancer with Integrated Positron-Emission Tomography and Computed Tomography
N Engl J Med. 2003;348:2500–2507. Lardinois D, Weder W, Hany TF, Kamel EM, Korom S, Seifert B, von Schulthess GK, Steinhert HC. University Hospital of Zurich, Zurich.
This prospective study was designed to compare the diagnostic accuracy of integrated whole-body positron emission tomography (PET) with fludeoxyglucose F 18 ([18F]fluoro-2-deoxy-D-glucose) and computed tomography (CT) with that of CT alone, that of PET alone, and that of conventional visual correlation of PET and CT in determining the stage of disease in 49 patients (28 men and 21 women; mean ag, 62 y; range, 46–81 y) with proven or suspected non-small-cell lung cancer. The tumor-node-metastasis (TNM) stage was assigned based on image analysis. Nodal stations were identified according to the mapping system of the American Thoracic Society. The standard of reference was histopathologic assessment of tumor stage and node stage. Extrathoracic metastases were confirmed histopathologically or by at least one other imaging method. Approximately 50 minutes after an intravenous injection of 350 to 400 MBq of fludeoxyglucose F 18, patients underwent imaging study during which image acquisition was performed with use of an integrated PET-CT device consisting of a PET scanner and a 4-slice CT scanner. The axes of both systems were mechanically aligned so that shifting the examination table by 60 cm moved the patient from the CT into the PET gantry. The resulting PET and CT images were coregistered on hardware. The analysis of data showed that integrated PET-CT provided additional information in 20 of 49 patients (41%), beyond that provided by conventional visual correlation of PET and CT. Integrated PET-CT also had better diagnostic accuracy than the other imaging methods. Tumor staging was significantly more accurate with integrated PET-CT than with CT alone (P = 0.001), PET alone (P < 0.001), or visual correlation of PET and CT (P = 0.013); node staging was also significantly more accurate with integrated PET-CT than with PET alone (P = 0.013). In metastasis staging, integrated PET-CT increased the diagnostic certainty in 2 of 8 patients. Histologic analysis revealed adenocarcinoma in 28 patients, squamous cell carcinoma in 13, and large-cell carcinoma in 8. The authors conclude that integrated PET-CT improves the diagnostic accuracy of the staging of non–small-cell lung cancer. CT has been the standard imaging procedure to assess thoracic lymph node involvement in patients with proven or suspected lung cancer. However, its ability to differentiate benign from malignant lymph node disease is not accurate. Although the PET scan possesses a higher rate of detection of mediastinal lymph node metastases as well as of extrathoracic metastases, it can be positive in nonmalignant diseases. The study discussed here evaluated the role of integrated PET-CT scanners and found that integrated PET-CT is superior to PET alone, CT alone, or visual correlation of PET with CT in determining the stage of disease in non-small-cell lung cancer. The results also showed significant improvements in tumor staging with integrated PET-CT. According to the authors, once integrated PET-CT becomes more widely available, it will be the preferred approach for determining the stage of disease in non-small-cell lung cancer.