Radiotherapy is a treatment using high-energy photon radiation to destroy cancer cells. The technique involves exposing a precisely defined part of the body to radiation with a view to destroying the tumour situated there. A linear accelerator produces radiation that treats the tumour in daily sessions lasting just a few minutes. Sophisticated computer systems direct the rays with the utmost precision. Liaising closely with dosimetrists and medical physicists, the radiation oncologist plans a radiation therapy schedule for individual patients. Each stage of the treatment is subject to stringent quality control.
On-board imaging and cone beam computed tomography enable operators to guarantee reproducible, high-precision radiation dose rates from one session to the next. In addition to external radiation, radiation oncology patients can also benefit from access to other forms of radiotherapy, such as intraoperative radiation therapy (IORT) for early-stage breast cancer and endorectal contact therapy for cancer of the rectum.