Objective: To correlate 18F-FDG PET metabolic response to therapy with histopathology and survival, in patients with locally advanced (stage III) non-small cell lung carcinoma (NSCLC) receiving induction chemotherapy.

Methods: A retrospective review of all patients with stage III NSCLC planned for induction chemotherapy and surgical resection, in whom pre- and post-chemotherapy FDG-PET at Austin Health between 2004 and 2007 was performed. The staging and positive nodal stations as determined by PET was compared to histopathological findings after resection. The tumour response on serial FDG PET was also compared to overall outcome.

Results: 9 patients were included. There was a 100 % correlation between pre- or post- chemotherapy nodal staging and final histopathological nodal stage. Ninety percent of all positive nodal stations (9/10) seen on histopathology were correctly localised by pre- or post-chemotherapy FDG PET. Only one patient with a metastatic lymph node at nodal station 9R could not be localised by prior PET studies. Of the patients in whom a down-staging in tumour status was observed on the post-chemotherapy FDG-PET, 83% (5/6) of patients were still alive (follow-up range of 8 to 40 months) as compared with 33% (1/3) (follow-up range of 9-13 months) for non-responders.

Conclusion: There is good correlation between pre- and/or post- chemotherapy FDG PET and final histopathology for the nodal staging of stage III NSCLC. There is an overall trend for those patients in whom PET resulted in a down-staging of tumour to have a longer survival.