External radiation is the most common type of radiation therapy used for head and neck cancer. It is used to aim high-energy rays or particles from outside the body into the tumor, thus passing through healthy tissue to varying degrees.
Types of External Radiation
There are multiple types of External Radiation, each is described below. More information about radiation can be found at www.radiologyinfo.org
Intensity Modulated Radiation Therapy (IMRT)
Image-guided radiotherapy (IGRT)
Stereotactic body radiation therapy (SBRT)
Stereotactic Radiosurgery (SRS)
Three-dimensional conformal radiation therapy (3D-CRT)
How long does external radiation treatment take?
For patients with adenoid cystic carcinoma, a primary diagnosis in the head or neck area normally involves daily radiation treatments, 5 days a week (Monday through Friday) for 6 to 7 weeks. Weekend rest breaks allow time for normal cells to recover.
The total dose of external radiation therapy is usually divided into smaller doses called fractions. This is because a large dose given one time can cause more damage to nearby normal tissues. Furthermore, ACC cells normally divide slowly. By spreading out the treatment plan, these cells are exposed to radiation as they divide overtime.
Other radiation schedules are used for other areas of the body such as metastasis the lungs, liver, bones, brain. For instance, radiation therapy might last only a few days (or less) when it’s used in these areas. Factors such as the stage, grade, tumor location, side-effects and general health of the patient are taken into consideration when developing your treatment plan.
