Radiation therapy is an effective cancer treatment because it works by damaging cells – normal cells are able to repair themselves, but cancer cells can't repair the damage and die. Many types of cancer can be treated with radiation therapy. Sugar Land Cancer Center uses a state of the art Varian linear accelerator, which allows us to more precisely target tumors while sparing healthy tissue.
Radiation therapy effectively treats many types of cancer, some of which include breast, colorectal, head and neck, prostate and gynecologic. In addition, radiation therapy may also be used to shrink tumors to reduce pain in patients with advanced cancers.
Radiation therapy can be useful in the treatment of cancer in several ways:
- Sometimes, radiation therapy is the only treatment that is needed. For example, many prostate cancer patients are treated with radiation therapy alone.
- Radiation therapy can also be used in conjunction with other treatments, either before or after. For example, radiation may be used before surgery to shrink the tumor so the surgery will be less extensive, but radiation therapy can also be used after surgery to destroy any cancer cells that may have remained.
- For advanced cancer, radiation therapy can be used to slow tumor growth or shrink tumors that interfere with body functions or cause pain (for example, a lung tumor that is making it difficult for a patient to breathe). This type of treatment will not cure the cancer, but may help improve the patient's quality of life.
Types of treatment:
The ultimate goal of radiation therapy is to use enough radiation to kill the cancer cells while minimizing damage to healthy tissue. External beam radiation therapy uses a machine that directs radiation at the cancer – much like a routine x-ray.
External Beam Radiation Therapy
When you are given external beam radiation therapy, the radiation beam is focused on the part of the body where the cancer is to destroy the main tumor and any nearby cancer cells. To minimize side effects, treatments are usually given five days a week, Monday through Friday, for up to seven or eight weeks. This schedule allows enough radiation to get into your body to kill the cancer while giving your healthy cells time to recover.
Our radiation beam is generated by a machine called a linear accelerator. The linear accelerator, or linac, produces high-energy X-rays and electrons to treat your cancer. Your treatment team uses complex treatment planning software to pinpoint the treatment site and plan the size, shape and direction of the beam to best treat your cancer while protecting the surrounding normal tissue.
Several special types of external beam therapy are discussed in the next sections. These are used for specific types of cancer, and your radiation oncologist will recommend one of these treatments if he or she believes it will help you.
Three-Dimensional Conformal Radiation Therapy (3D-CRT)
Tumors come in different shapes and sizes. Three-dimensional conformal radiation therapy, or 3D-CRT, uses computers and special imaging to help pinpoint the size, shape and location of the tumor. Using computer assisted tomography (CT scans), magnetic resonance imaging (MRI scans) and/or positron emission tomography (PET scans), the Dosimetrist creates a treatment plan from detailed, three-dimensional representations of the tumor and surrounding organs. Your Radiation Oncologist then precisely tailors the radiation beams to your tumor with custom fabricated field shaping blocks. Because the radiation beams are so precisely directed, nearby normal tissue receives less radiation and is able to heal quickly.
Intensity Modulated Radiation Therapy (IMRT)
Intensity modulated radiation therapy, or IMRT, is a more advanced form of 3D-CRT that allows the radiation beams to be more precisely shaped to fit the tumor. With IMRT, the beam can be broken into many smaller beams and the intensity of each smaller beam can be adjusted individually. IMRT may help to further limit the radiation that affects healthy tissue near the tumor. In some cases, this may also permit higher doses of radiation to be delivered to the tumor, potentially increasing the chance for a cure.
Electron Beam Therapy
Superficial Electron Beam Radiotherapy offers a non-surgical alternative to treat localized skin cancers - both basal cell carcinomas and squamous cell carcinomas. This therapy is particularly suited to therapy for cancers found on the face - including the nose, ears, and eyelids.
Superficial electron beam radiotherapy should be considered by those facing possible cosmetic alterations from surgery, or for whom surgery could pose a health risk. Superficial electron beam radiotherapy utilizes state-of-the-art linear accelerators to generate a therapeutic beam that can destroy skin cancers while often maintaining excellent cosmetic results. Each treatment takes only minutes, and is entirely painless and requires no anesthesia or cutting. Patients do not need to take any time off work and can continue their lives normally without interruption. There is no need to stop medications (such as blood thinners) during treatment.
Partial Breast Irradiation (PBI)
Partial breast irradiation therapy is indicated in women with early breast cancer that has not spread to the axillary lymph nodes. PBI is given via the linear accelerator using a 3D-conformal radiation therapy (3D-CRT) technique and requires only 1 week of twice daily radiation treatment instead of the usual 6 week, once daily radiation treatment. PBI reduces the treatment area from the entire breast to the area of the breast immediately around the lumpectomy site. This is the part of the breast where most cancers are likely to recur. The goal is to use a less invasive more focused treatment without compromising survival.