For most cancers, external radiation therapy is given four or five days a week for five to seven weeks. Taking two or three days off a week helps normal cells to recover. The course of treatment is shorter for palliative care and usually lasts two to three weeks.
Research has shown that giving many smaller doses of radiation is better than a few large doses. The treatment is as effective and damage to healthy tissues is reduced. Radiation is usually given once daily, but sometimes the daily dose is divided into two or more sessions. This is called fractionated radiation therapy.
The most common type of machine used for external beam radiation is a linear accelerator. The prescribed dose of radiation is carefully programmed into the radiation therapy machine before your treatment.
For each session, you will change into a hospital gown or robe. Once in the treatment room, you will lie down on a treatment table. The radiation therapist positions you using the marks on your skin and customized molded forms that help you stay in place. The rest of your body is protected by shields placed between you and the machine.
If you need radiation therapy, you may have to travel to a larger hospital or freestanding radiation therapy center. When medically possible, external beam radiation can be provided on an outpatient basis. Patients usually require a short hospital stay for internal radiation.
You may be sent to a radiation oncologist for a consultation. A radiation oncologist is a specialist who prescribes the type and amount of treatment that is right for you. During this visit, you and the doctor will discuss
Both internal and external radiation therapy can be used as:
- Curative therapy, where the goal is to eliminate all signs of cancer.
- Palliative therapy, which relieves symptoms, including pain. Lower doses are given over a shorter period of time.
- Adjuvant Therapy, which means using it in combination with other in combination with surgery, chemotherapy (use of anti-cancer drugs that destroy cancer cells), hormone therapy, or other treatments.
Adjuvant radiation therapy can be used:
Cancer cells reproduce faster than normal cells in the body. Radiation therapy targets these rapidly dividing cells. The radiation reacts with water in the cells and this reaction damages the DNA or genetic material in the cell that controls cell growth.
Normally, cells can repair themselves and continue growing. But since cancer cells can't repair themselves as easily, they die. Although normal cells are also affected, they repair themselves more effectively.
Radiation therapy is one of several treatments used to treat cancer by itself or in combination with other forms of treatment, most often surgery or chemotherapy. Radiation therapy is also called radiotherapy.
You've probably seen an X-ray of your teeth or some other part of your body. At high doses - many times greater than those used for X-ray exams - radiation can kill cancer cells and shrink tumors. More than half of all cancer patients receive some radiation therapy as part of their treatment.
When the U.S. Preventive Services Task Force (USPSTF) recommended against routine mammograms for women 40 to 49 years of age in its revised guidelines for breast cancer screening in November 2009, clinicians and patients alike squirmed with discomfort, and advocacy groups like The American Cancer Society dug in their heels to reject the recommendations. That’s because USPSTF basically said that less might be more when it comes to screening for breast cancer.
A bit of disclosure before I launch into this post: My dermatologist has said the “M” word – as in melanoma, a deadly form of skin cancer– to me more than once after a biopsy of a suspicious spot. I lost a dear, dear uncle to malignant metastatic melanoma nearly two decades ago. He was in his mid-forties. He spent his last weeks at my parents’ house, in horrible pain despite an on-demand morphine drip.
It was an offhand conversation with a neighbor that sent me back to the keyboard today, this time to write about cigarettes and other forms of tobacco, prevention, denial, and death. Said neighbor and his 12-year-old son were building my two-year-old’s new easel, a birthday present from Grandma — a job that would have taken me weeks, and even then I would have probably built it upside-down. An old friend had stopped by, and we were talking about changes in “The Valley,” the frontier community where we live. Another neighbor and friend had passed away shortly after my daughter’s birth.