About Radiation Therapy
Radiation therapy, also known as radiotherapy, is a common treatment for cancer that uses high-energy radiation to kill cancer cells.
What is Radiation Therapy?
Radiation therapy, also known as radiotherapy, is a medical treatment that uses high doses of radiation to kill cancer cells and shrink tumors. This therapy works by damaging the DNA within cancer cells, which prevents them from growing and dividing. Over time, the damaged cancer cells die and are naturally eliminated by the body. Radiation therapy can be delivered externally or internally, depending on the type and location of the cancer.
External beam radiation therapy is the most common form of radiation therapy. It involves using a machine called a linear accelerator to direct high-energy beams of radiation at the cancerous area from outside the body. The machine can move around the patient to target the tumor from different angles, ensuring that the maximum dose of radiation is delivered to the cancer cells while minimizing exposure to surrounding healthy tissues.
Internal radiation therapy, or brachytherapy, involves placing a radioactive source directly inside or near the tumor. This method allows for a higher dose of radiation to be delivered to a more localized area, reducing the risk of damage to nearby healthy tissues. Brachytherapy is often used for cancers of the prostate, cervix, and breast.
Radiation therapy can be used at different stages of cancer treatment. It may be employed as the primary treatment to eradicate cancer, or it can be used before surgery (neoadjuvant therapy) to shrink tumors, making them easier to remove. After surgery, radiation therapy (adjuvant therapy) can help eliminate any remaining cancer cells. Additionally, it can be combined with other treatments, such as chemotherapy, to enhance the overall effectiveness.
Radiation therapy is a critical component of modern cancer treatment, with more than half of all cancer patients receiving it at some point during their treatment. Its ability to precisely target cancer cells while sparing healthy tissues makes it an invaluable option for many types of cancer.
Types of Radiation Therapy
Radiation therapy, a cornerstone in cancer treatment, employs various techniques to target and destroy cancer cells. The two primary types of radiation therapy are external beam radiation therapy (EBRT) and internal radiation therapy.
External beam radiation therapy (EBRT) is the most prevalent form. It involves using a machine called a linear accelerator to direct high-energy beams of radiation at the cancer from outside the body. This method is highly versatile and can treat many types of cancer, including those of the brain, breast, lung, and prostate. Within EBRT, there are several advanced techniques:
3D Conformal Radiation Therapy (3DCRT): This technique uses three-dimensional scans to map the exact shape and size of the tumor. Radiation beams are then shaped to match the tumor, minimizing exposure to surrounding healthy tissues.
Intensity-Modulated Radiation Therapy (IMRT): IMRT delivers radiation in varying intensities from multiple angles. This allows for higher doses to be concentrated on the tumor while sparing nearby healthy tissue.
Image-Guided Radiation Therapy (IGRT): IGRT uses imaging during treatment to improve precision. It is particularly useful for tumors that move, such as those in the lungs or liver.
Volumetric Modulated Arc Therapy (VMAT): VMAT delivers radiation in a continuous arc around the patient, allowing for precise targeting and reduced treatment times.
Internal radiation therapy, also known as brachytherapy, involves placing a radioactive source directly inside or near the tumor. This method is often used for cancers of the prostate, cervix, and breast. Brachytherapy allows for a high dose of radiation to be delivered to a localized area, minimizing damage to surrounding tissues.
Another form of internal radiation therapy is systemic radiation therapy, which involves administering radioactive substances orally or intravenously. These substances travel through the bloodstream to target cancer cells throughout the body. This approach is commonly used for thyroid cancer and certain types of lymphoma.
Intraoperative Radiation Therapy (IORT) is a specialized form of internal radiation given during surgery. It delivers a concentrated dose of radiation to a tumor site while sparing surrounding healthy tissues. IORT is often used for cancers that are difficult to remove completely through surgery alone.
Why is Radiation Therapy done?
Radiation therapy is a crucial treatment modality in the fight against cancer, utilized for its ability to target and destroy cancer cells with precision. The primary goal of radiation therapy is to treat cancer by damaging the DNA within cancer cells, which prevents them from growing and dividing. This treatment can be used in various stages and for different purposes in cancer management.
One of the main reasons radiation therapy is employed is as a primary treatment to eradicate cancer. In some cases, it is the sole treatment used to cure cancer, especially for localized tumors that have not spread to other parts of the body. For instance, early-stage cancers of the head and neck, prostate, and cervix can often be effectively treated with radiation therapy alone.
Radiation therapy is also used before surgery (neoadjuvant therapy) to shrink tumors, making them easier to remove surgically. This approach can increase the likelihood of a successful surgery and reduce the risk of cancer recurrence. Conversely, after surgery (adjuvant therapy), radiation therapy can help eliminate any remaining cancer cells that were not removed during the operation, thereby reducing the risk of the cancer coming back.
In addition to its curative potential, radiation therapy plays a significant role in palliative care. For patients with advanced cancer, where a cure is not possible, radiation therapy can be used to relieve symptoms and improve quality of life. It can help shrink tumors that are causing pain, pressure, or other symptoms, such as difficulty breathing or swallowing.
Radiation therapy is often combined with other treatments, such as chemotherapy, to enhance its effectiveness. This combination can be particularly beneficial in treating certain types of cancer, such as head and neck cancers, where the synergy between radiation and chemotherapy can lead to better outcomes.
Moreover, radiation therapy is not limited to cancer treatment. It can also be used to treat non-cancerous conditions, such as benign tumors and certain neurological disorders. For example, it can be used to shrink benign brain tumors or to treat trigeminal neuralgia, a chronic pain condition affecting the facial nerves.