FDG-PET/CT Imaging for Staging and Target Volume Delineation in Preoperative Conformal Radiotherapy of Rectal Cancer

Imaging with PET/CT for preoperative radiotherapy of rectal cancer may lead to a change in staging and target volume delineation. Stage variation was observed in 12% of cases and a change of treatment intent in 4%. The GTV and CTV changed significantly, with a mean increase in size of 25% and 4%, respectively.