Positronen-emissions-tomographie (PET) mit ¹⁸F-fluorodeoxyglukose in der stadienzuordnung und therapieentscheidung des nichtkleinzelligen bronchialkarzinoms: Stellenwert der PET und der PET/CT-koregistrierung

The high diagnostic accuracy of positron emission tomography (PET) in lung cancer and the acceptance of PET for therapy planning was shown by the observations of the referring physicians, by a large number of clinical studies and by a randomized trial in the Netherlands. The referring physicians reported that PET caused an intermodality management change in 39% of their patients. Regarding the detection of mediastinal lymph node metastases in clinical studies, the mean sensitivity of PET was 86% (95% confidence interval 82 - 90%) and the negative predictive value was 92% (95% CI 88 - 95%). For the detection of distant metastases, FDG-PET correctly changed the tumor stage in 14% of the patients, the percent rate varied with the number of conventional diagnostic tests used. The randomized trial in the Netherlands demonstrated the improvement of the outcome when FDG-PET was added to the preoperative staging: the risk of a futile thoracotomy was reduced from 41% to 21%. The worldwide increasing market of integrated PET/CT machines requires clinical studies to compare CT and PET alone, visually correlated PET and CT, and integrated PET/CT, as done by the working group in Zurich. The PET/CT coregistration reduced the rate of correct but equivocal classifications from 38% to 3% compared with the separate PET and CT interpretation. The visual correlation of PET and CT did not improve the diagnostic accuracy. The acquisition time is halved by the use of integrated PET/CT machines, which is essential for an economic use of capacity of the CT. PET is reimbursed not only in the USA, but also in the most European countries within a broad spectrum of indications. Thus, the worldwide market of integrated PET/CT machines is increasing.