At the Center for Thoracic Oncology at Boston Medical Center, we specialize in many of the latest and most effective cancer treatments, including radiation. Our team of highly trained and experienced specialists takes a collaborative approach to your treatment. We draw on medical expertise, state-of-the-art facilities, and a patient-centered environment to provide you with not only the best medicine but also the best patient care in New England.
Radiation uses special equipment to deliver high-energy particles—such as x-rays, gamma rays, electron beams, or protons—to kill or damage cancer cells. Radiation (also called radiotherapy, irradiation, or x-ray therapy) can be delivered internally through seed implantation or externally using linear accelerators (called external beam radiotherapy, or EBRT). Radiation may be used as a solitary treatment or in conjunction with surgery and/or chemotherapy.
The equipment used to deliver the radiation therapy is called a linear accelerator. The linear accelerator has a moveable arm, which enables the radiation to be focused on the part of your body where the cancer is located. Developments in EBRT equipment have enabled physicians to offer conformal radiation. With conformal radiation, computer software uses imaging scans to map the cancer three-dimensionally. The radiation beams are then shaped to conform, or match, the shape of the tumor.
Radiation works by breaking a portion of the DNA of a cancer cell, which prevents it from dividing and growing. Radiation therapy can be systemic, meaning it throughout your bloodstream. Systemic therapies are usually given as an injection into a blood vessel or are taken as a pill. Systemic treatments expose your entire body to cancer-fighting medication. Radiation therapy is typically given as a "local" treatment, however, meaning it affects only the part of the body that needs therapy.
The entire dose of radiation given in external radiation therapy typically cannot be given all at once. Although the radiation in external radiotherapy is tightly focused, some damage can occur to normal cells near the cancerous cells. It can also cause more side effects than giving a smaller dose of radiation over a longer period. Therefore, physicians typically divide radiation treatments in to smaller doses, called fractions. Typically, external radiation therapy is delivered 5 days a week for 5 to 8 weeks, which allows any nearby normal tissue a chance to recover during treatment.
How to Prepare
A few days before your first external radiation treatment, your physician will pinpoint the exact location of your cancer through a simulation. You will lie on a table while a radiation therapist uses a special x-ray machine to determine the treatment field, which is the exact place in your body where the radiation beams will be focused. To ensure that the radiation beams are aimed correctly, the therapist will make special molds of your body to help you remain still during treatment. In addition, the therapist may use a pen to mark the treatment fields on your body with dots, which should remain there until you complete your treatment.
What to Expect
External radiation therapy is painless and is similar to having a regular x-ray. Although the actual treatment can take only a few minutes, treatment sessions can last from 15 to 30 minutes because the equipment must be prepared and you must be positioned correctly. Depending on the area to be treated, you may need to undress and parts of your body that are not being treated may be covered with a shield to protect you from unintended radiation (similar to an x-ray).
You will lie on the treatment table, which is next to the linear accelerator. The therapist will then use alignment lasers and the marks on your body to position you correctly. Once you are in position, the radiation therapist will move to another room to operate the linear accelerator. The radiation therapist will be able to monitor you by a video camera and an intercom system. You will be asked to lie still during the therapy. The machine will make whirring or clicking noises while it is active and its arm will move during treatment to aim the radiation beam to different parts of your body.
Radiation is usually performed on an outpatient basis, over the pre-determined period. Most patients experience little to no side effects, and you should be able to resume your normal activities immediately. Call us if you notice anything of concern or if you have questions. Be sure to schedule and attend any follow-up appointments that your physician advises.