FDG PET in monitoring response to neoadjuvant chemoradiotherapy in patients with locally advanced non-small lung carcinoma

  • Dr Salvatore Berlangieri, Austin Health, Australia
  • Dr Sze Ting Lee, Austin Health, Ludwig Institute for Cancer Research, University of Melbourne, Australia
  • Dr Andrea Chan, Austin Health, Australia
  • Dr Paul Mitchell, Austin Health, Australia
  • Dr Simon Knight, Australia
  • Dr Malcolm Feigen, Austin Health, Australia
  • Dr Andrew Scott, Austin Health, Ludwig Institute for Cancer Research, University of Melbourne, Australia

    • Aim: The aim of our study was to correlate 18F-FDG PET response to neoadjuvant chemoradiotherapy with histopathology in patients with locally advanced non-small cell lung carcinoma.

    Methods: All patients with stage III NSCLC planned for surgery following induction chemotherapy and/or radiotherapy who underwent pre- and post-treatment FDG-PET between 2004 and 2007 were retrospectively reviewed. The PET scans were performed according to standard protocol. The clinical FDG-PET TNM stage was correlated with the histopathology of the surgical specimens.

    Results: There were 9 patients (6M:3F), median age 59.7 years (range 49 to 73 years). Post-treatment FDG-PET correctly predicted mediastinal pathological N stage in 8/9patients, with one patient having microsopic disease in two nodes. The post-treatment FDG-PET correctly predicted pathological T stage in 7/9 patients, with 2 patients having small volume T4 disease not detected by PET. Post-treatment FDG-PET correctly downstaged 4 patients. Of the 5 patients, incorrectly staged on the post-treatment FDG-PET, one patient had microscopic pN2 disease, 2 had pN1 disease, and 2 had pT4 disease.

    Conclusion: Post-treatment FDG-PET is predictive of pathological nodal stage within the mediastinum in patients with locally advanced NSCLC treated with neoadjuvant chemoradiotherapy. FDG-PET does not detect microscopic or small volume disease, nor is it able to define the boundaries of mediastinal tissue invasion.