Radiation therapy, often abbreviated as XRT, is a medical treatment using high doses of radiation, primarily in oncology, to destroy diseased cells or slow their growth. This localized approach targets specific areas of the body. XRT can be used alone or in conjunction with other therapies to improve outcomes.
Understanding Radiation Therapy
Radiation therapy operates on the principle of damaging the genetic material within diseased cells. It uses high-energy particles or waves, such as X-rays, electron beams, or gamma rays, to disrupt the DNA of these cells. When the DNA is damaged beyond repair, the cells lose their ability to grow and divide, eventually leading to their death. The body then naturally breaks down and removes these damaged cells.
While radiation can affect healthy cells, cancer cells are particularly vulnerable due to their rapid reproduction rate. Normal cells possess a greater capacity to repair themselves from radiation-induced damage. Precision in delivery is important, with treatment planned to maximize the dose to the target while minimizing exposure to surrounding healthy tissues. Advanced techniques refine this targeting, allowing for varying dose intensities to deliver higher radiation to the tumor and lower doses to healthy tissue.
Conditions Treated with XRT
XRT is primarily used for cancer treatment. It can serve as a curative treatment. Radiation therapy is also employed as a palliative measure to shrink tumors and alleviate symptoms like pain when a cure is not possible. It is often integrated with other cancer therapies, used before surgery to shrink tumors (neoadjuvant therapy) or after surgery to destroy any remaining cancer cells (adjuvant therapy), reducing the chance of recurrence.
Beyond cancer, XRT treats several non-cancerous conditions. Benign tumors, though not spreading, can cause symptoms by compressing surrounding structures; radiation therapy can shrink or eliminate these growths. Examples include certain benign tumors. Radiation is also effective for inflammatory or proliferative disorders like keloids, which are raised scars that extend beyond the original wound edges. Superficial radiation therapy, often used after surgical removal, reduces keloid recurrence.
The XRT Treatment Process
The XRT process begins with a consultation where a radiation oncologist evaluates the patient and discusses treatment options. If XRT is chosen, the next step is simulation, an important planning appointment. During simulation, the patient is positioned exactly as they will be for daily treatments, often with the aid of immobilization devices like molds or masks to ensure consistent positioning. CT scans, and sometimes MRI or PET scans, are performed to precisely map the tumor’s location and surrounding healthy tissues. Temporary or permanent skin markings, often tiny tattoos, may be made to guide daily setup.
Following simulation, a multidisciplinary team, including radiation oncologists, medical physicists, and dosimetrists, plans the treatment. They use specialized software to calculate the exact radiation dose and design beams that target the diseased area while sparing healthy tissue. This planning process can take several days to a week.
Actual treatment sessions typically last 10 to 30 minutes, with the radiation delivery itself taking only a few minutes. During external beam radiation therapy, a large machine called a linear accelerator moves around the patient, delivering precise radiation doses without physical contact. Radiation therapists operate the machine from a separate room, maintaining communication with the patient via intercom.
Managing Side Effects
Side effects from radiation therapy are localized to the treated area and can vary depending on the body part receiving radiation and the dose. Acute side effects occur during or shortly after treatment and are temporary, resolving within weeks to months after therapy concludes. Fatigue is a common side effect, affecting individuals regardless of the treated area. Skin changes in the treated area, resembling a sunburn, are also frequent and may include redness, itching, dryness, or peeling.
Other side effects are specific to the treated region; for instance, radiation to the head and neck can cause mouth and throat issues, while abdominal or pelvic treatment might lead to nausea or urinary changes. Hair loss may occur in the treated area, but not elsewhere on the body. Managing these effects involves gentle skin care using mild soaps and moisturizers, avoiding harsh products or excessive rubbing. Patients are advised to protect treated skin from sun exposure and wear loose-fitting clothing. Adequate rest, proper nutrition, and open communication with the care team are also important for managing symptoms and maintaining well-being throughout treatment.