2 The condition, current treatments and procedure
2.1 Rectal cancer is a common form of bowel cancer. The likelihood of developing it rises sharply with age. Symptoms include rectal bleeding, obstruction, perforation, pain and discharge. Symptoms may also result from the tumour invading local structures (such as the bladder). Early stages of rectal cancer may be asymptomatic and between 5% and 10% of patients present with locally advanced disease (stage T3b to T4).
2.2 Surgery offers the best chance for cure in some patients with locally advanced rectal cancer. In patients who elect not to have surgery, or are not fit enough to have it, local surgical resection with systemic or radiation therapies, or both may be given. The aim is to reduce the tumour size, alleviate symptoms and improve quality of life.
2.3 Low-energy contact X‑ray brachytherapy (CXB, or the Papillion technique) for locally advanced rectal cancer may be given with external beam radiotherapy or chemotherapy, or both. It is usually delivered in a day-patient setting. The patient is given an enema before treatment to empty the rectum. With the patient in a knee-to-chest, prone jack-knife or supine position, local anaesthesia and glyceryl trinitrate are applied to the anal sphincter to numb the area and relax the sphincter muscles. A sigmoidoscope is inserted through the anal sphincter to ascertain the size and position of the tumour. Subsequently, a rigid endorectal treatment applicator is inserted and placed in contact with the tumour. A contact X‑ray tube is introduced into the applicator and emits low-energy X‑rays that penetrate tissue by only a few millimetres, minimising damage to deeper tissues.