What is Radiation Therapy?
Radiation therapy, also called radiotherapy, is a type of cancer treatment. Radiotherapy is a cornerstone of cancer treatment that uses targeted high-energy X-rays or other types of radiation to destroy or damage cancer cells. It is an essential component of cancer care, and in many cases, it complements surgery, chemotherapy, and other therapies to achieve the best treatment outcomes.
How Radiation Therapy Works Against Cancer?
Radiotherapy works against cancer by using high-energy radiation to target and damage the DNA inside cancer cells. This damage interferes with the cancer cells’ ability to grow and divide, ultimately leading to their destruction. Here’s how radiation therapy works:
- Precise Targeting: Radiation therapy is designed to deliver a highly focused dose of radiation to the specific area of the body where cancer is located. Modern technology, such as computerized tomography (CT) scans and magnetic resonance imaging (MRI), helps create detailed treatment plans to ensure precise targeting.
- Ionizing Radiation: Radiation used in therapy can be X-rays or other types of ionizing radiation. These high-energy particles or waves have enough energy to damage the DNA within cells.
- Damaging DNA: When radiation is delivered to the cancerous area, it interacts with the DNA in cancer cells. This interaction can break the DNA strands, create free radicals, and damage the genetic material within the cells.
- Interrupting Cell Division: Cancer cells are characterized by their rapid and uncontrolled division. The damage to their DNA hinders their ability to divide and reproduce. As a result, the cancer cells may stop growing or die.
- Cell Death: After radiation exposure, some cancer cells will undergo cell death, while others may lose their ability to divide and grow. The body’s natural processes then remove the damaged or dead cells.
- Fractionation: Radiation therapy is often delivered in multiple sessions or fractions. This allows for effective treatment while minimizing damage to healthy surrounding tissues. The cumulative effect of multiple treatments enhances the destruction of cancer cells over time.
- Immune Response: Radiation therapy can stimulate the body’s immune system to recognize and attack cancer cells. This is particularly important in the context of immunotherapy, where the combination of radiation and immunotherapy enhances the body’s ability to fight cancer.
- Tumor Shrinkage: Radiation therapy can also shrink tumors, making them more manageable for surgical removal or other treatments.
Types Of Radiation Therapy
Radiation therapy encompasses several types, each with specific techniques and applications. The choice of radiation therapy type depends on the type of cancer, its location, the stage of the disease, and the patient’s overall health. Here are some common types of radiation therapy:
- External Beam Radiation Therapy (EBRT): In EBRT, a machine outside the body, such as a linear accelerator, delivers radiation beams precisely targeted at the tumor. Various techniques, such as intensity-modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT), enhance the precision of EBRT.
- 3D Conformal Radiation Therapy: This approach uses 3D imaging to shape the radiation beams to match the shape of the tumor, reducing exposure to healthy tissue.
- Image-Guided Radiation Therapy (IGRT): IGRT employs real-time imaging, such as X-rays or CT scans, to ensure the tumor’s exact position during each treatment session. It allows for highly precise targeting, particularly when treating tumors affected by movement (e.g., lung tumors).
- Intensity-Modulated Radiation Therapy (IMRT): IMRT adjusts the intensity of radiation beams at multiple angles, optimizing the dose to the tumor while sparing healthy tissue. This is particularly useful for complex tumor shapes and locations.
- Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT): These techniques deliver high doses of radiation in a single or a few sessions. SRS is commonly used for brain tumors, while SBRT is applied to tumors in the body, such as lung tumors.
- Proton Therapy: Proton therapy uses protons, rather than X-rays, to target tumors. It can deliver a precise dose of radiation while minimizing damage to nearby healthy tissue. Proton therapy is particularly beneficial for pediatric cancers and certain adult tumors.
- Brachytherapy: In brachytherapy, radioactive sources are placed inside or very close to the tumor. This can be used for various cancers, including prostate, cervical, and breast cancer. Brachytherapy can be permanent (seeds left in place) or temporary (sources are removed after treatment).
- Intraoperative Radiation Therapy (IORT): IORT involves delivering a single, high dose of radiation directly to the tumor during surgery. This is commonly used for certain cancers where it’s challenging to separate the tumor from healthy tissue.
- Tomotherapy: Tomotherapy combines radiation therapy with CT scanning in a single machine. It provides detailed imaging and targeted radiation delivery.
- Gamma Knife Radiosurgery: Gamma Knife is a specialized device for delivering highly focused radiation, primarily used for brain tumors and other neurological conditions.
Types of Cancer That Are Treated with Radiation Therapy
Radiation therapy is used to treat various types of cancer, either as the primary treatment or in combination with other therapies. Some of the common types of cancer that can be treated with radiation therapy include:
- Breast Cancer
- Prostate Cancer
- Lung Cancer
- Head and Neck Cancer
- Brain and Central Nervous System Tumors
- Cervical Cancer
- Gastrointestinal Cancers
- Bladder Cancer
- Gynecological Cancers
- Bone Cancer
- Skin Cancer
- Soft Tissue Sarcomas
- Thyroid Cancer
- Pediatric Cancers
These are just some of the many types of cancer that can be treated with radiation therapy. The choice of treatment and the radiation therapy technique used depend on the individual patient’s condition, the type and stage of cancer, and the goals of treatment.