2 Indications and current treatments
2.1 Rectal cancer is a common form of bowel cancer. The likelihood of developing it rises sharply with age. Symptoms include rectal bleeding and change in bowel habit, although the early stages may be asymptomatic.
2.2 Surgery is the main treatment for patients with rectal cancer who are treated with curative intent. It involves resection of the affected part of the rectum and the mesorectum. The anal sphincter is preserved whenever possible: a colostomy is formed when this is not possible.
2.3 In some patients, radiotherapy or chemotherapy or both are used before, during or after surgery to decrease the chances of local recurrence and metastatic disease. Radiotherapy may take the form of external beam radiation therapy (EBRT) or brachytherapy. EBRT uses radiation from outside the body, which is focused on the cancer and surrounding lymph nodes. Brachytherapy involves placing a radioactive source (pellet, seed or catheter) directly into or near the tumour. In contact brachytherapy (the Papillon technique) a low energy X‑ray tube is used to deliver radiation to the tumour with limited penetration.
2.4 Preoperative high dose rate endorectal brachytherapy uses localised radiotherapy, with the aim of shrinking the tumour before surgery with fewer side effects than EBRT.