Stereotactic radiotherapy (SRT) is a newer type of focused radiation therapy that precisely and accurately delivers high dose radiation to a tumour, while sparing much of the nearby normal organs. The use of stereotactic radiotherapy results in high rates of tumour destruction with minimal side effects which are very well tolerated. Often stereotactic radiotherapy has been used to try to cure patients who have an early stage cancer which has not spread, but there is less experience with using it in patients with cancer which has spread.