Internal radiation

This refers to the use of radiation sources (usually sealed in needles, wires or seeds within a tumour exploiting the physics inverse square law to deliver a huge dose of radiation on the tumour and yet relatively spare the surrounding tissues. The use of such internal radiation is commonplace in tongue and oral cancer, and in prostate cancer therapy.

In cancer of the cervix uteri, the sources are contained within cathaters that are place in the vagina and uterus.

See also 'Brachytherapy'.