Radiation therapy can be used to treat many types of cancer, including cancers of the breast, prostate, lung, head and neck, brain, cervix, rectum and skin. It may also be used for certain blood cancers and other tumours. The role of radiation varies depending on the cancer's type, stage, location and treatment goals. Radiation oncologists may use radiation alone or as part of a broader treatment plan that includes surgery, chemotherapy or other systemic therapies.

External beam radiation therapy delivers radiation from a machine outside the body and directs it toward the tumour. Different techniques can shape and target the radiation in different ways to limit exposure to nearby healthy tissue. Other approaches include brachytherapy, in which a radioactive source is placed inside or close to the treatment area, and certain forms of systemic radiation therapy that travel through the bloodstream to target specific cancer cells. The appropriate technique depends on the cancer and its location.

Treatment planning begins with understanding the cancer's type, stage, size and location and the surrounding healthy organs and tissues. Imaging, often including CT scans, is used to map the treatment area and determine how radiation should be delivered. The radiation oncologist decides the appropriate dose, treatment technique and schedule while aiming to give the tumour an effective dose and minimize exposure to healthy tissue. The plan is individualized according to the patient's diagnosis, treatment goals and previous or planned cancer therapies.

Side effects depend largely on the part of the body being treated, the radiation dose and the patient's individual response. Fatigue and skin changes in the treatment area are common. Depending on the treatment site, patients may experience symptoms such as hair loss in the treated area, nausea, changes in bowel habits, mouth or throat discomfort or difficulty swallowing. Some effects occur during treatment, while others may develop later. The radiation oncology team monitors patients and can recommend measures to prevent or manage side effects.

Yes. Radiation therapy is frequently combined with other cancer treatments when doing so can improve cancer control. It may be given before surgery to shrink a tumour, after surgery to reduce the risk of recurrence, or together with chemotherapy in cancers where combined treatment is beneficial. Depending on the cancer, radiation may also be incorporated into treatment plans involving immunotherapy or targeted therapy. The sequence and combination are determined by the cancer type, stage, treatment goals and the patient's overall health.

Before treatment begins, your radiation oncology team will explain the purpose of radiation, the area being treated, the expected schedule, potential side effects and how they will be managed. Treatment is usually planned carefully using imaging, and the radiation itself is generally painless during delivery. Ask what you can expect before, during and after each session, whether you need any special preparation, how treatment may affect your daily activities and which symptoms should be reported promptly. Understanding the plan can make treatment more predictable and manageable.