Influence of introduction of positron emission tomography on adherence to mediastinal staging protocols and performance of mediastinoscopy.

Purpose: In this study, we investigated the impact of implementation of [(18)F] fluorodeoxyglucose positron emission tomography (FDG-PET) in daily practice on adherence to mediastinal staging protocols and performance of mediastinoscopy in non-small-cell lung cancer (NSCLC) patients who are possible candidates for surgical resection. Institutional review board approval was obtained.

Patients And Methods: From a nonuniversity teaching hospital and three surrounding community hospitals in Eindhoven, the Netherlands, we studied data from 143 patients with NSCLC who underwent mediastinoscopy and/or thoracotomy in three consecutive periods (1, 0 to 9 months; 2, 10 to 18 months; and 3, 19 to 31 months) after introduction of PET. Mediastinoscopy was indicated in case of enlarged and/or PET-positive nodes. Adherence to these surgical mediastinal staging guidelines and the performance of PET and mediastinoscopy were investigated and compared between the three periods and with our previous study before introduction of PET.

Results And Conclusion: Guidelines for indicating mediastinoscopy were adequately followed in significantly more instances after introduction of PET (80%), compared with the period before PET (66%). Optimal yield (lymph node stations 4, right and left, and 7) of mediastinoscopy (in 27% of patients) was not significantly different from the period before PET (39% of patients). Compared with the historical data, the percentage of positive mediastinoscopies increased from 15.5 to 17.6 (not significant). We found no significant differences between the three consecutive periods with regard to adequacy of indicating and performance of mediastinoscopy. After introduction of PET, adherence to staging guidelines with respect to mediastinoscopy improved. Although fewer mediastinoscopies had an optimal yield, more proved to be positive for metastases. Nevertheless, when a mediastinoscopy is indicated, surgeons must be encouraged to reach an optimal yield because PET positive nodes might be false negative. This occurred in 5% to 6% of all patients.