FDG-PET, PET/CT and conventional nuclear medicine procedures in the evaluation of lung cancer

Summary Aim: Currently, the German and Austrian S3 guidelines on the evaluation and treatment of lung cancer are about to be published whereas the American Colleague of Chest Physicians (ACCP) guidelines were already presented in 2007. An important part of the diagnostic workup of lung cancer will be the evaluation of indeterminate lung lesions and the mediastinal and extrathoracic staging using FDG-PET or PET/CT. The results from the literature on FDG-PET and PET/ CT as well as on conventional nuclear medicine staging procedures and the clinical implications are presented. Methods: The literature data was amassed in analogy to the metaanalyses drawn for the current ACCP guidelines. In addition, relevant more recent publications were also considered. To answer the important question for the extent of pathological confirmation needed, the residual risk of mediastinal metastases was calculated for certain constellations of FDG-PET and CT findings. Suggested recommendations were characterized with the level of evidence. Results: FDG-PET (PET/CT) allows the differentiation of indeterminate lung lesions with high accuracy. FDG-PET (PET/ CT) is the most accurate non-invasive procedure to assess the mediastinal nodal stage, for non-small cell as well as for small cell lung cancer. It is justified to omit invasive evaluation of enlarged but FDG-PET negative lymph nodes under certain circumstances. Unexpected extrathoracic metastases detected by FDG-PET imply important changes in therapeutic management. Conclusion: The upcoming S3 guideline on lung cancer will recommend FDG-PET in several indications due to its clinical efficacy well proven by data from literature (high level of evidence). The selected use of conventional nuclear medicine procedures remains beyond doubt. FDG-PET (PET/CT) belongs to the standard of care in lung cancer.