Radiation Therapy

Definition

Radiation therapy is a cancer treatment that uses high-energy particles or waves, such as x-rays, gamma rays, electron beams, or protons, to destroy or damage cancer cells. It is a widely used medical application of radioactivity that can be employed for both diagnostic and treatment purposes.

5 Must Know Facts For Your Next Test

1. Radiation therapy can be used to treat a wide range of cancers, including solid tumors and hematological malignancies.
2. The goal of radiation therapy is to damage the DNA of cancer cells, causing them to die or stop growing.
3. Radiation therapy can be used alone or in combination with other cancer treatments, such as surgery, chemotherapy, or targeted therapies.
4. Radiation therapy can be delivered externally (external beam radiation therapy) or internally (brachytherapy) using radioactive sources.
5. Careful planning and delivery of radiation therapy is crucial to maximize the effectiveness of the treatment while minimizing the risk of side effects.

Review Questions

• Explain how radiation therapy works to destroy cancer cells.
  • Radiation therapy works by delivering high-energy particles or waves, such as x-rays or protons, to the tumor site. These ionizing radiations interact with the DNA of cancer cells, causing damage that leads to cell death or inhibits their ability to grow and divide. The goal is to selectively target and destroy the cancer cells while minimizing the impact on surrounding healthy tissues.
• Describe the different types of radiation therapy and their applications.
  • There are two main types of radiation therapy: external beam radiation therapy, where the radiation source is outside the body, and brachytherapy, where radioactive sources are placed directly into or near the tumor. External beam radiation therapy can be further divided into techniques like intensity-modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT), which allow for more precise targeting of the tumor. Brachytherapy is often used for cancers of the prostate, cervix, or breast, where the radioactive sources can be placed in close proximity to the tumor.
• Analyze the role of radiation therapy in a comprehensive cancer treatment plan.
  • Radiation therapy is often used in combination with other cancer treatments, such as surgery, chemotherapy, or targeted therapies, to maximize the effectiveness of the overall treatment plan. Radiation therapy can be used as a primary treatment to shrink or destroy the tumor, as a neoadjuvant therapy to reduce the size of a tumor before surgery, or as an adjuvant therapy to kill any remaining cancer cells after surgery. It can also be used palliatively to relieve symptoms and improve quality of life for patients with advanced or metastatic cancer. The specific role of radiation therapy in a patient's treatment plan depends on the type and stage of cancer, as well as the overall goals of the treatment.

Related terms

Ionizing Radiation: High-energy radiation that can ionize atoms and molecules, causing damage to cells, tissues, and DNA.

Radiopharmaceuticals: Radioactive substances that are administered to patients for diagnostic or therapeutic purposes, such as in nuclear medicine.

Brachytherapy: A type of radiation therapy where radioactive sources are placed directly into or near the tumor, delivering a high dose of radiation to the cancer cells.