Brachytherapy is the placement of radioactive material, usually in the form of tiny rods, into a cancer in order to destroy it. The rods are inserted through a needle that is placed into the tumour or affected organ. This allows the radiation to be delivered in an exact dose to the very centre of the cancer in a way that the chances of total destruction of the cancer can be maximised, while minimising the side effects to surrounding tissues. It may be sued in conjunction with external radiotherapy and chemotherapy.
Moderate to severe cancer of the prostate is the most common tumour to be treated with brachytherapy. About 50 to 100 fine rods or pellets containing radioactive material may be inserted into the prostate. The radioactive material (eg. iridium 192) is removed when no longer required, which varies from 24 to 48 hours. The exact positioning and dosage of the implants is determined by a computerised analysis of the cancer, its position and shape. The results of brachytherapy are often better than with surgical removal of the prostate, and with fewer side effects such as impotence and incontinence. Cure rates in excess of 90% are quoted by some centres that deal with medium severity prostate cancer. The main side effect, which occurs in about 5% of patients, is damage to the urethra (urine tube that passes through the prostate), making it difficult to pass urine.