Brachytherapy is the delivery of radiotherapy by putting the radioactive source in apposition to the malignancy.
Thus a source - usually Caesuim 137 but historically Radium - can be placed into a body cavity like the uterus or implanted into a solid tumour. The source can be afterloaded into a tube created during a previous operation, thus reducing the exposure of the medical personnel to ionising radiation.
The radiation dose falls off as the square of the distance from the source, and therefore the tumour receives a high dose with little radiation reaching the surrounding normal tissue.
Last reviewed 01/2018