Integrated PET/CT in non small cell lung cancer staging--clinical and pathological agreement

Abstract

Introduction: Integrated PET/CT has become a fundamental tool in the preoperative assessment of non small lung cancer (NSCLC) providing useful anatomical and metabolic information to characterize tumoral lesions and to detect unsuspected metastatic disease.

Aim: To compare the agreement between clinical and pathological staging before and after the use of PET/CT.

Material and methods: Retrospective study of patients with NSCLC who underwent potentially curative surgery throughout 10.5 years. Cohen's kappa coefficient was used to evaluate staging agreement.

Results: One hundred and fifty patients were evaluated, 78% males, with a mean age of 65 (±9.6) years. Thirteen percent were submitted to neoadjuvant chemotherapy. PET/CT was performed in 41%. Global agreement between clinical and pathological staging was 51% (kappa=0.3639). There was a statistically significant difference between the staging results in patients who underwent PET/CT, when compared to the subgroup who did not (p=0.003). For those with PET/CT false negatives occurred in less 39%, false positives in more 12% and clinical and pathological staging coincided in more 27%. The overall results reflected an improvement in the agreement between clinical and pathological staging in the PET/CT subgroup (67%, kappa=0.5737 vs 40%, kappa=0.2292). PET/CT accuracy was enhanced when patients re-staged after neoadjuvant therapy were excluded and a substantial staging agreement was obtained for those who had the exam only for staging purposes (73%, kappa=0.6323).

Conclusion: Inclusion of PET/CT in NSCLC preoperative assessment improved the accuracy of the clinical staging, with a good level of agreement with pathological staging.