Dr. John A. Greager II is an oncology physician and surgeon working to heal and support his patients on their cancer journey. In the following article, John A. Greager provides a detailed understanding of radiation therapy, its mechanisms, types, procedures, side effects, and the critical role it plays in cancer treatment.
Radiation therapy, a cornerstone in the battle against cancer, employs high-energy radiation to target and destroy cancer cells. As one of the most
common forms of cancer treatment, radiation therapy is used either alone or in combination with other treatments such as surgery, chemotherapy, or immunotherapy.
Dr. John A. Greager Explains More on Radiation Therapy
Radiotherapy uses
high doses of radiation to kill cancer cells and shrink tumors. Unlike x-rays used for imaging, radiation therapy delivers a much higher dose of radiation to target and eradicate malignant cells. The primary goal is to damage the DNA of cancer cells, preventing them from growing and/or dividing. Over time, these damaged cells die off, and the body naturally eliminates them.
How Radiation Therapy Works
Radiation therapy works by damaging the genetic material within cancer cells, thus hindering their ability to reproduce. While radiation affects both cancerous and normal cells, normal cells have a better ability to repair themselves after exposure, whereas cancer cells do not. John A. Greager explains that this differential repair capability is the basis for the selective targeting of cancer cells by radiation therapy.
Types of Radiation Therapy
External Beam Radiation Therapy (EBRT)
External Beam Radiation Therapy
(EBRT) is the most common type of radiation therapy. It involves directing high-energy beams from outside the body onto the cancerous tissues. EBRT can be delivered using various techniques:
- 3D Conformal Radiation Therapy (3D-CRT): Uses imaging technologies to map the shape and size of the tumor precisely, allowing for targeted radiation delivery while sparing healthy tissues.
- Intensity-Modulated Radiation Therapy (IMRT): Adjusts the intensity of the radiation beams and can target tumors with complex shapes more effectively.
- Stereotactic Body Radiation Therapy (SBRT): Delivers highly focused radiation in fewer high-dose treatments, often used for small, localized tumors.
- Proton Therapy: Uses protons instead of x-rays, allowing for more precise targeting with potentially fewer side effects.
Internal Radiation Therapy (Brachytherapy)
Dr. John A. Greager II reports that Internal Radiation Therapy, or Brachytherapy, involves placing radioactive sources directly inside the body or near the tumor. This allows for a higher dose of radiation in a more localized area, minimizing exposure to surrounding healthy tissues. Brachytherapy can be categorized as:
- Interstitial Brachytherapy: Implants radioactive seeds directly into the tumor.
- Intracavitary Brachytherapy: Places radioactive sources within a body cavity close to the tumor site.
The Radiation Therapy Procedure
Planning
The process begins with a planning phase, where the radiation oncology team, including radiation oncologists,
dosimetrists, and medical physicists, conducts a simulation. John A. Greager says that this often involves imaging studies such as CT, MRI, or PET scans to precisely locate the tumor and surrounding tissues.
Simulation
During simulation, the patient is positioned in the same way they will be for treatment. Custom molds, masks, or cushions may be created to ensure consistent positioning. Marks or small tattoos might be placed on the skin to guide the precise targeting of radiation.
Treatment Delivery
Treatment is typically administered over several weeks, with sessions occurring five days a week. Each session lasts only a few minutes, though setup time can be longer. John A. Greager notes that during treatment, the patient lies on a table while the radioactivity machine moves around them to deliver radiation from multiple angles.
Side Effects of Radiation Therapy
Side effects of radiation therapy vary depending on the treatment area and dose. Common side effects include:
- Fatigue: Often occurs due to the body's effort to repair radiation damage.
- Skin Reactions: Redness, irritation, or blistering in the treated area.
- Hair Loss: Only in the treatment area.
- Nausea and Vomiting: Common when the abdomen is treated.
- Loss of Appetite: Can lead to weight loss and nutritional deficiencies.
- Specific Organ-Related Effects: For example, difficulty swallowing when treating the throat or chest.
Most side effects are temporary and can be managed with the help of the healthcare team. Long-term side effects depend on the radiation dose and treatment area but can include tissue scarring, changes in organ function, and secondary cancers.
The Benefits of Treatment
Radiation therapy offers several benefits, including:
- Targeted Treatment: Precision in targeting cancer cells while minimizing damage to healthy tissues.
- Non-Invasive: Particularly with EBRT, the treatment is non-invasive compared to surgical options.
- Combination Therapy: Can be used alongside other treatments to enhance overall effectiveness.
- Palliative Care: Effective in relieving symptoms and improving quality of life in advanced cancer stages.
Advances in Therapeutic Techniques
Dr. John A. Greager II explains that technological advancements continue to improve the efficacy and safety of radiation therapy. Innovations such as adaptive radiation therapy, which adjusts treatment based on real-time imaging, and the use of artificial intelligence to enhance treatment planning are paving the way for more personalized and precise cancer treatments.
Conclusion
Radiation therapy remains a vital tool in the fight against cancer, offering targeted, effective treatment with manageable side effects. Understanding the intricacies of radiation therapy, from its types and mechanisms to the treatment process and potential side effects, empowers patients and their families to make informed decisions about their care. John A. Greager says that as research and technology advance, radiation therapy continues to evolve, providing hope and improved outcomes for countless individuals battling cancer.
