Preoperative high dose rate brachytherapy for rectal cancer

The procedure

Preoperative high dose rate brachytherapy aims to shrink the tumour before surgery.

The procedure is usually done with the patient under sedation. An enema is given to clear the bowel before treatment starts. A local anaesthetic and a muscle relaxant are applied to the ring of muscle around the anus. A tube (sigmoidoscope) is inserted through the anus into the bowel to see the size and position of the tumour. An applicator containing a source of radiation is placed in contact with the tumour. The radiation only penetrates a few millimetres so that damage to tissues not associated with the cancer is reduced.