Radiation therapy uses high-energy rays or particles to treat cancer, destroying cancer cells and shrinking tumors. For endometrial cancer, which originates in the lining of the uterus, it aims to eliminate cancer cells or prevent their return, either alone or with other therapies. The application of radiation therapy is a carefully planned process, considering the specific characteristics of the cancer and the patient’s overall health.
How Radiation Therapy Works
Radiation therapy damages the DNA within cancer cells. High-energy beams, often X-rays, are directed at the tumor, breaking the DNA strands of rapidly dividing cancer cells. This damage prevents cancer cells from growing, dividing, and repairing themselves, ultimately leading to their death.
While radiation targets cancer cells, it can also affect healthy cells in the treatment area. However, healthy cells are generally more capable of repairing themselves from radiation-induced damage than cancer cells. The goal of radiation therapy planning is to maximize the dose delivered to the tumor while minimizing exposure to surrounding healthy tissues, allowing these healthy cells to recover.
Advanced technologies precisely shape and direct radiation beams. This careful targeting concentrates the destructive energy on the cancerous region, helping to prevent its spread and shrink existing tumors.
Types of Radiation Therapy for Endometrial Cancer
Radiation therapy for endometrial cancer primarily involves two distinct methods: external beam radiation therapy (EBRT) and brachytherapy. Each method delivers radiation differently and serves specific purposes in treatment. The choice between these types, or their combination, depends on factors such as the cancer’s stage, grade, and location.
External Beam Radiation Therapy (EBRT)
External Beam Radiation Therapy (EBRT) delivers radiation from a machine outside the body. A linear accelerator (linac) directs high-energy beams to the tumor and surrounding tissues. EBRT is often used after surgery to eliminate any remaining cancer cells in the pelvis or as the main treatment for advanced or inoperable cases. Techniques like Intensity-Modulated Radiation Therapy (IMRT) refine EBRT delivery. IMRT divides the radiation into many small, computer-controlled doses, allowing doctors to tailor the radiation dose precisely to the tumor’s size, shape, and location while reducing exposure to nearby healthy organs like the intestines and bladder.
Brachytherapy
Brachytherapy, also known as internal radiation therapy, involves placing radioactive materials directly into or very close to the tumor. For endometrial cancer, a radioactive source is often inserted into the vagina, typically using a cylinder-shaped applicator. This method delivers a high dose of radiation directly to the targeted area, limiting spread to distant healthy tissues.
Vaginal cuff brachytherapy is commonly used after a hysterectomy to prevent cancer recurrence in the upper vagina. High-dose rate (HDR) brachytherapy is a common type, delivering strong radiation for short periods, usually 10 to 20 minutes per session. This localized treatment helps reduce the risk of cancer returning in the vagina.
Navigating Treatment and Managing Side Effects
Before treatment begins, patients typically have a consultation with a radiation oncologist to discuss the treatment plan. A “simulation” appointment follows, where the medical team takes measurements and imaging scans (CT or MRI) to create a personalized treatment map. During simulation, patients are positioned on a treatment table, often using immobilization devices to help them remain still. Small marks are often placed on the skin to ensure the patient is in the same position for each daily treatment session.
Actual treatment sessions are short, lasting around 15 to 20 minutes, and are generally painless. Patients are alone in the treatment room, but the radiation therapists can see and hear them through cameras and microphones. Most external beam radiation treatments are given once a day, five days a week, for a period of four to six weeks. Brachytherapy sessions might be fewer, sometimes two to three sessions, or weekly/daily for at least three doses.
Patients may experience various short-term side effects during and immediately after radiation therapy. Common short-term effects include fatigue, which can be severe and last for weeks after treatment, and skin irritation in the treated area, ranging from redness to peeling. Gastrointestinal issues like diarrhea, nausea, and abdominal cramping are also common, along with urinary changes such as increased frequency or urgency. Vaginal irritation, dryness, or discharge can also occur, particularly with brachytherapy. These side effects are often temporary and managed with medications, dietary adjustments, and self-care practices.
Long-term side effects can emerge months or even years after treatment and depend on the type and dose of radiation received. Vaginal dryness, scarring, and narrowing (vaginal stenosis) can occur, potentially making sexual activity painful. Lymphedema, severe swelling due to fluid blockage, can develop in the legs, especially if pelvic lymph nodes were removed during surgery. Additionally, radiation to the pelvis can weaken bones, increasing the risk of hip or pelvic fractures, and lead to persistent bowel or bladder problems. Healthcare providers offer strategies, such as vaginal dilators for scarring or specialized physical therapy for lymphedema, to help manage these lasting effects.