Following resection and treatment, patients do not represent a uniform population of equal risk of recurrence and may require different imaging modalities or colonoscopy to monitor disease progression. CT, PET/CT and MR are routinely used to monitor patients with colon and rectal cancers.8
8. Radiotherapy for Colorectal Cancer: Current Standards and Future Perspectives. Matthias F. Häfnera,b,* and Jürgen Debusa,b Visc Med. 2016 Jun; 32(3): 172–177.