Recent advances in delineation of clinical target volume in radiotherapy for rectal cancer

The delineation of clinical target volume (CTV) is a critical step in planning conformal radiotherapy for rectal cancer. Several guidelines suggest different subvolumes and anatomical boundaries in radiotherapy for rectal cancer, potentially leading to a misunderstanding of CTV definition. This article reviews recent advances in the delineation of CTV in radiotherapy for rectal cancer. Key words: Rectum neoplasms; Radiotherapy; Clinical target volume; Target delineation