Long-term prognostic value of 18F-FDG PET in patients with locally advanced rectal cancer previously treated with neoadjuvant radiochemotherapy

OBJECTIVE. The purpose of this study was to assess the prognostic value of 18F-FDG PET performed at restaging in patients with locally advanced rectal cancer who previously underwent neoadjuvant radiochemotherapy.SUBJECTS AND METHODS. Eighty-eight patients with histologically proven rectal cancer classified at clinical TNM stages II and III were enrolled. Six weeks after radiochemotherapy completion, all patients were restaged by sonography, CT, MRI, endoscopy, and 18F-FDG PET. Surgery was performed in all patients within 8-9 weeks from completion of radiochemotherapy. Median follow-up after surgery was 38 months (range, 6-66 months).RESULTS. The 5-year overall survival and disease-free survival were 83% and 73%, respectively. Cox multivariate analysis showed that only two parameters at restaging were independent prognostic predictors of both overall survival and disease-free survival: pathologic stage and, especially, after radiochemotherapy 18F-FDG PET findings. The 5-year overall survival was 91% in pa...