Radiation Therapy

Radiation therapy uses high-energy radiation to damage the DNA of cancer cells and stop them from growing and dividing. Unlike chemotherapy, which usually works throughout the body, radiation therapy is primarily a local treatment directed at a specific area.

Radiation therapy is widely used for many solid tumors and is also used for certain lymphomas, leukemias, and other blood cancers. Depending on the treatment goal, it may be used as the main treatment, before or after surgery, or in combination with chemotherapy, targeted therapy, or immunotherapy.

Whether radiation therapy is appropriate depends on the cancer type, location, stage, tumor size, extent of spread, and the patient's overall health.

For some solid tumors, including certain head and neck cancers, cervical cancer, prostate cancer, and lung cancer, radiation therapy may be part of curative treatment. It may also be given before surgery to shrink a tumor or after surgery to reduce the risk of local recurrence.

For certain blood cancers, particularly lymphoma, radiation may be used to treat localized disease or as consolidation after systemic therapy. In leukemia, radiation is not usually the main treatment but may be used in selected situations, such as disease involving the central nervous system or specific extramedullary sites.

For advanced cancer, radiation therapy can also help relieve symptoms caused by bone metastases, tumor compression, or bleeding.

Most cancer radiation therapy is delivered using external beam radiation. Before treatment, patients usually undergo CT-based simulation so the treatment team can define the tumor area, nearby organs, radiation dose, and treatment schedule.

External beam radiation is often delivered in multiple sessions, allowing an effective dose to reach the tumor while limiting damage to surrounding healthy tissue. Depending on the cancer, techniques such as stereotactic radiation therapy or brachytherapy may also be used.

Radiation treatment itself is generally painless. During the treatment course, patients are monitored regularly and may undergo imaging or laboratory tests as needed.

Side effects depend mainly on the area being treated, radiation dose, treatment volume, and whether radiation is combined with other cancer therapies.

Fatigue and skin reactions in the treated area are relatively common. Radiation to the head and neck may cause mouth sores, dry mouth, or difficulty swallowing. Chest radiation may cause esophagitis or radiation-related lung injury, while abdominal or pelvic radiation may cause nausea, diarrhea, or bladder irritation.

Many side effects improve after treatment ends, but some late effects can develop months or even years later. Long-term follow-up is therefore an important part of radiation therapy care.