External Beam Radiation

Radiation oncology is the use of radiation, a special kind of energy carried by waves or streams of particles, as a method for treating cancerous tumors by destroying a cancer cell’s ability to reproduce. A cancer patient may be treated with radiation alone, or radiation therapy may be part of a patient’s treatment program – which may include surgery (surgical oncology) and/or chemotherapy (medical oncology).

 “Basic” External beam radiation: like an X-ray, the photon beams come in from the head of the gantry (the round top portion of the machine that rotates around the patient). The field can be set clinically or with the help of a CT. Best example is a palliative (to help relieve pain or other symptoms) case to treat a palpable mass. We can feel the mass and give a certain margin around it and thus this is our field. However if we use a CT, we are not drawing any contours or volumes – we can just use it to eyeball the area we want to include. Most of the time, if we do a CT (which is almost always at TCC), we will want to draw in volumes so that our treatment will be more accurate (but this then becomes 3DCRT).

Radiation oncology utilizes a multidisciplinary approach to cancer treatment involving a collaborative effort among physicians, physicists, dosimetrists, nurses, scientists, technologists, and other support staff.

A radiation oncologist may treat cancer using radiation produced by a free-standing machine, i.e. external beam radiation therapy, and radiation may also be administered with radioactive sources that are placed inside the patient, i.e. Brachytherapy of either the prostate or breast.